Proceedings ofthe United StatesNational MuseumSMITHSONIAN INSTITUTION ? WASHINGTON, D.C.Volume 125 1968 Number 3656Copepod Crustaceans Parasiticon Fishes of Eniwetok Atoll ^
By Alan G. Lewis ^
Copepod parasites of fishes of Eniwetok Atoll, one of the MarshallIslands, have not been previously studied. The only reference dealingwith parasitic copepods from this general region of the Pacific is thatof Heegaard (1943) concerning some caligids from the GUbert Islands.Both Heegaard (1940, 1962) and Kabata (1964, et al), however,have described copepods from fishes from the neighboring Australianregion, some of which are also found on fishes from Eniwetok Atoll,and Hewitt (1963, et al.) and Thomson (1889) have described copepodsfrom fishes of New Zealand. These studies, as weU as those of Lewis(1964a, et al.) concerning copepods from Hawaiian fishes, cover mostof the named species although some of them have previously beendescribed from other areas, prunarHy the western Pacific and theIndian Ocean.The study herein reported is based on two collections made by theauthor during the summers of 1959 and 1961. He is indebted to theU.S. Atomic Energy Commission for the use of the facilities at theEniwetok Marine Biological Laboratory. He is also grateful for the
1 This study was supported by a grant (GB-3932) from the National ScienceFoundation.2 Associate Professor of Zoology and Oceanography, Institute of Oceanography,University of British Columbia, Vancouver, B.C., Canada. 1
2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125
assistance given to him by James Coatsworth, John Shoup, andDavid Au, who were serving as research assistants at the EniwetokMarine Biological Laboratory during the periods when the collectionswere made. Finally, the author appreciates the help given to him bymembers of the Division of Crustacea of the Smithsonian Institutionduring the time of final examination of the specimens in the collections.Methods.?The external surface, gill cavities, buccal cavity, andnasal cavities of the hosts were examined for parasitic copepods.Copepods collected were killed and preserved in 95 percent ethylalcohol. Specimens to be drawn or dissected were placed in 85 per-cent lactic acid to clear and soften them, stained with ChlorazolBlack E dissolved in 85 percent lactic acid, and then placed in benzylalcohol for final clearing and for dissection and drawing.Drawings of the entire animal were made from specimens placedin benzyl alcohol and covered with a cover slip, supported so thatthe shape of the organism was not distorted. A camera lucida wasused in makmg the drawings. The appendages and processes wereTable 1.
?
Armature of hypothetical thoracic leg shown in figure 1
Leg
COPEPODS?LEWISdimHmp nne'dH\nnH
Figure 1.?Hypothetical thoracic leg showing the various armament components (a= ad-hesion pad; C= large plumosities; c= small plumosities; Cl= large spikehke extension ofsegment; cl=small spikelike extension of segment; D= large denticulations; d= smalldenticulations; dH= large spine with denticulations; dh= small spine with denticulations;dm= denticulated membrane; dmH= large spine with denticulated membrane or mem-branes; fH= large spine with frilled membrane or membranes; fm= frilled membrane;H= large spine; h= small spine; IP= interpodal plate; m= membrane; mH= large spinewith simple membrane or membranes; mp= setule with membrane on both sides; mp'=setule with membrane on one side, naked on other; n 1,2,3= endopodite segments one,two, three; P= plumose seta; P'= naked seta; PROT=protopodite; p= plumose setule;p'= naked setule; Q=seta with plumosities on one side, membrane on other; Q'= setawith plumosities on one side, naked on other; r=numerous minute projections givingrugose appearance; rh= spinule; s= hairlike process; x 1,2,3 =exopodite segments one,two, three; Z= spine with frilled membrane on one side, simple membrane on other) .
4 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125segments" and "free pedigerous segments" are used to designate thosethoracic segments that are not fused with the cephalon. The term
"genital segment" is used, with some reservation, to designate thefused sixth and seventh thoracic segments (= fifth and sixth pedigeroussegments) in the Caligidea (Caligoidea of Yamaguti, 1963). The term
"ovigerous" is used to indicate a female with egg strings, the term
"nonovigerous" to indicate a female without egg strings even thoughthe genital segment may contain eggs.The terminology applied to the appendages and processes is thesame as that in Lewis (1967). To facilitate the use of the thoracic legtables, a hypothetical thoracic leg is shown in figure 1, giving thevarious thoracic leg armature elements used in the tables; an analysisof the hypothetical thoracic leg is given in table 1.Order CYCLOPOIDAFamily BomolochidaeNothobomolochus gibber (Shiino)Figures 2-4Bomolochus gibber Shiino, 1957, p. 411, figs. 1-2.Nothobomolochus gibber (Shiino).?Vervoort, 1962, p. 70.Pseudartacolax gibber (Shiino).?Yamaguti, 1963, p. 14, pi. 8, fig. 1.Host and distribution.?Tylositrus giganteus, Japan.Material.?8 females and 2 males (USNM 120739) from the gillcavity of Belones platyura Bennett.Measurements (in mm).?7 females and 2 males:female
COPEPODS?LEWISthoracic leg. Third and fourth pedigerous segments separable ventrally,fused dorsally; dorsal surface topshaped although irregular, greatestwidth shghtly more than that of second pedigerous segment; posteriorsurface overlapping fifth pedigerous (first urosomal) segment.
ai mm.?cr 0.1 mm. 9Figure 2.
?
Nothohomolochus gibber (Shiino, 1957): a, female dorsal view; b, male, dorsalview; c, male, genital segment, ventral view; d, female, genital segment and part of eggstring, ventral view; e, same, dorsal view;/, caudal ramus, ventral view.
6 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125Female fifth pedigerous segment slightly less than half the widthof thu'd and fourth, widest medially, in region of leg attachment.Genital segment (figs. 2d, e) broadest medially, tapered to posteriorand anterior ends. Ovidiical openings situated on lateral dorsalsiu"face, region around openings ornamented with heavily sclerotizedplatelets. Sixth legs situated on dorsal sm"face, adjacent to oviducalopenings, consisting of 3 lightly plumose setae originating from nodule.First segment of female abdomen subrectangular, length approxi-mately three-fourths that of genital segment. Second segment sub-rectangular, fom'-fifths the length of first. Third segment sHghtlylonger than second, tapered posteriorly, posterior siu"face with bilobedanal indentation. Caudal ramus (fig. 2/) subconical, bearing 3 nakedor hghtly plumose setules on outer surface and large, lightly plumoseseta as well as 2 hghtly plumose setules from distal siu-face.Cephalothorax and free second pedigerous segment of male (fig. 26)generally similar to those of female. Third and foiu-th pedigeroussegments chstinct, not fused as in female. Both segments of aboutequal length, third approximately one and one-third times the widthof fom'th. Fifth pedigerous, genital, and abdominal segments similarto those of female.Female and male antennule (fig. 3a) 5-segmented, attached toventral sm-face of inner lobe of bilobed projection at anterior end ofcephalothorax. Segment lengths, in micra, 205:135:90:95:100. Firstsegment vnih base at right angles to rest of segment and appendage,bearing 14 hghtly plumose setae along anterior surface, 3 nakedsetides on posterior distal sm'face. Second through fifth segmentsrodlike; second with 6 Hghtly plmnose and 3 naked setules, thirdwith 3 naked setules, foiu-th with 2 naked setae on distal sm-face.Fifth segment with single, naked setule on distal posterior surface,also with 3 naked setules and one naked seta on cUstal surface.Female and male antenna (fig. 36) 3-segmented, attached slightlyposterior and lateral to antennule base. First segment approximatelyequal to combined lengths of remaining two, tapered towards distalend, with single naked seta distally. Second segment short, unarmed.Third segment with ventrally facing rows of clawHke denticulationsalong entire sm-face and extending on toelike projection of distalsurface. Distal surface also with 2 denticidated spines (one not shownin figure), one clawlike spine, and 5 clawlike setae.Female and male mandible (figs. 2>c,d) 1 -segmented, basal regionenlarged, with heavily sclerotized medial ridge; distal half rodlike.Distal end of segment bearing 1 large and 1 small, flattened spinesserrated along anterior margins. Maxillule (fig. 3c) nodular, situatedimmediately posterior to mandible base, with 2 plumose setae and 2plumose setules. Maxilla (figs. 3c,e) 2-segmented, proximal segment
COPEPODS?LEWIS
C y- 0.1 mm. 9cr e ' 0.1 mm. 9cj'
/ 0.1 mm. 9cfFigure 3.
?
Nothobomolochus gibber (Shiino, 1957), female, ventral views: a, left antennule;h, right antenna; c, left side of oral region, showing labrum, mandible, paragnath, maxil-lule and maxilla; d, right mandible; e, right maxilla;/, left maxilliped.
8 PROCEEDINGS OF THE NATIONAL MUSEUMlarge, irregular; second segment short, rodlike, bearing 2 stiffly plumoseterminal spines and 1 naked subterminal setule. Labrum (fig. 3c)apron-shaped, anterior surface with very fine projections giving fuzzyappearance to surface. Paragnath (fig. 3c) situated medial and poste-rior to maxillule base, bladeshaped, distal half of margins finelydenticulated. Anteriorly V-shaped, posteriorly rounded padlike projec-
0.2 mm. 9CC e ^ 0.2 mm. 9c?Figure 4.
?
Nolhohomolochus gibber (Shiino, 1957), thoracic legs: a, left first, ventral view;b, left second, anterior view; c, right third, anterior view; d, right fourth, anterior view;
e, right fifth, ventral view.
COPEPODS?LEWIS 9tion present immediately posterior to maxilla, extending betweenmaxillae bases.Female and male maxilliped (fig. 3/) 2-segmented, base situatedlateral to maxilla base, body extending anteriorly to antenna base.First segment strongly developed, broad proximally, tapered distally,bearing single, long, finely plumose seta from knob on distal innersurface. Second segment short, inner surface cuplike, outer surfacerounded; distal surface with large, sharply curved claw and finelyplumose seta.Thoracic legs 1-4 biramous, fifth leg uniramous. Ramal count 3-3on first 4 legs. For nature of legs and armature, see figure 4 and table 2.
Table 2.
?
Armature of thoracic legs I-V of the female and male of Nothobomolochusgibber {Shiino, 1967)
Leg
10 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125
3. Part of the surface of the labrum has a "fuzzy" appearance dueto numerous, minute projections. Shiino figures the labrum withoutthe projections.4. Shiino states (p. 415) that, in the first thoracic leg, "both therami (are) fringed by stout long spines with multiserial barbs; . , ."This condition was not evident in the Eniwetok material.5. The antennae of the Eniwetok specimens possess 2 denticulatedsubterminal setae on the third segment while Shiino indicates thatthere is only 1.In spite of these differences, the Eniwetok specimens agree closelywith Shiino's original description and, based on this similarity, arebelieved to be conspecific with A^. gibber.
Pseudotaentacanthus speciesFigures 5, 6Material.? 1 adult male (USNM 120740) from the externalsurface of Acanthurus gahhm (Forskal)
.
Measurements (in mm).? 1 male:Greatest length, excluding caudal setae 1. 73Length of prosome 0. 81Width of prosome 0. 63Length of cephalothorax 0. 49Length of genital segment 0. 18Width of genital segment 0. 27Description.?Body (fig. 5a) of general cyclopoid shape: cephalo-thorax of general bell shape, consisting of cephalon, maxilliped-bearing and first pedigerous segments. Anterior end of cephalothoraxrounded although slightly concave medially, set off from rest ofcephalothorax by lateral indentation and line of heavy sclerotizationextending medially and curving posteriorly from lateral indentation.Lateral margins flatly convex, posterior margin irregularly concave.Second pedigerous segment distinct from cephalothorax, widthapproximately nine-tenths that of cephalothorax; lateral surfaceswinglike, lateral margins flatly convex. Third pedigerous segmentdistinct from second, appearing slightly narrower than second althoughof similar shape. Fourth pedigerous segment distinct from third,approximately three-fourths its length, lateral surfaces winglike, asin preceding free pedigerous segments, although lateral margins morerounded.Fifth pedigerous segment without winglike lateral projections,forming first segment of urosome; slightly narrower anteriorly thanposteriorly. Genital segment (fig. 56) barrel-shaped, slightly morethan one and one-half times the length of fifth pedigerous segment;
COPEPODS?LEWIS 11
0.1 mm. d*
Figure S .?Pseudotaeniacanihus species, male: a, dorsal view; b, left side of genital segmentventral view; c, left caudal ramus, ventral view; d, left antennule, ventral view; e, antenna,region showing antennule base (A-1), antennal base (A-2), and adjacent processes;/, right antenna, posterior view.
12 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125lateral posterior region lobate, lobes bearing genital openings andsixth legs. Sixth leg consisting of single finely plumose setule. Foursegments present posterior to genital segment, first approximatelyequal to length of genital segment, second approximately nine-tenthsits length, third and fourth approximately three-fourths its length.Posterior segments narrower than anterior, lateral margins of first 3almost parallel, fourth tapered posteriorly, posterior margin withsmall anal indentation and distinct lateral concavities, at place ofattachment and articulation of caudal rami. Caudal rami (fig. 5c)elongate, subrectangular, with setule-bearing indentation in distalhalf of outer surface; distal surface with 3 naked setae and 1 nakedsetule, additional naked setule present on dorsal surface just proximalto distal end.Antennule (fig. 5d) 6-segmented, attached to anterior-lateral ven-tral surface of cephalothorax, adjacent to small, spikeshaped projec-tion from lateral anterior surface of cephalothorax. First segment(may represent 2 fused segments) strongly flattened proximally,rodlike distally; bearing 19 naked or very lightly plumose setides.Second segment approximately one-third the length of first, with 4naked or lightly plumose setules. Third segment approxunately halfthe length of first, with 3 naked setules. Fourth segment slightlymore than one-third the length of first, bearing 3 naked setules. Fifthsegment slightly less than one-third the length of fu-st, with 2 nakedsetules. Sixth segment slightly more than one-thii-d the length of first,rounded distally, bearing single naked setule from medial posteriorsurface, 5 naked setules from distal surface. Antenna (fig. 5/) 4-segmented, situated posterior and medial to antennule base. Firstsegment strongly developed, distal siu-face with naked setule. Secondsegment approxunately half the length of first, subrectangular. Thirdsegment, excluding terminal processes, slightly shorter than secondwith deep indentation in medial outer surface; distal surface with 2spatulate and one clawlike projection, inner lateral surface of segmentand spatulate process with denticulated membrane or individualdenticulations. Fourth segment arising from indentation in third,rodlike, bearing 7 naked setae and setules distally.Mandible (fig. 6a) 1-segmented, broad proximally, irregularlytapered distally, with spineshaped projection distally; second spine-shaped projection arising from distal half of posterior surface; bothprojections with denticulations, distalmost with single longitudinalrow on posterior surface, proximal projection with 2 rows. Maxillule(fig. 6a) nodidar, situated immediately posterior to mandible base,bearing 4 naked setae. Maxilla (fig. 6a) appearing 2-segmented, firstsegment swollen, nodular, second segment arising from inner lateralsurface of first, rodlike, bearing 2 naked setules and single spatulate
COPEPODS?LEWIS 13
0.1 mm. o? ff I I . . < 1o 0.1 mm. cfFigure 6.
?
Pseudotaeniacanthus species, male, ventral views: a, right side of oral region,showing mandible, paragnath, maxillule, and maxilla; b, left maxilliped. Thoracic legs:
c, right first, posterior view (see table 3 for discussion of position of rami); d, right second,anterior view; e, right third, anterior view; /, left fourth, anterior view; g, left fifth, an-terior view.
14 PROCEEDINGS OF THE NATIONAL MUSEUMprocess distally, spatulate process denticulated distally. Paragnath(fig. 6a) small, nodidar, without distinctive armature.Ventral surface of cephalothorax with numerous heavily sclerotizedknobs, adhesion processes and spikes. Postantennal process (fig. 56)most prominent, extending as ridge from lateral anterior surfaceposteriorly to oral region, terminating as spinelike projection; ridgebearing 2 adhesion pads. Postantennal processes contiguous at basebut not fused. Prominent pair of spinelike projections situated im-mediately lateral to antenna base, in position of postantennal processof many caligoids.
Table 3.
?
Armature of thoracic legs I-V of the male of Pseudotaeniacanthus species
NO. 3656 COPEPODS?LEWIS 15Discussion.?The single male specimen from Eniwetok differs fromthe diagnosis of the genus given in Yamaguti (1963) in the followingcharacteristics:1. The lateral extensions of the second to fifth pedigerous segmentsare not as large.2. The antenna is 4-segmented, not 3-segmented. The conditionexhibited in the third and fourth segments of the antenna of theEniwetok specimen suggests that the terminal segment of the antennaof previously described species may be composed of 2 fused, or par-tially fused segments.3. The postantennal processes are contiguous at their base but arenot fused and do not form the characteristic Y-shaped structure pres-ent on other members of the genus. Additionally, although there are2 adhesion pads on each postantennal process, the projections onthese pads do not have the characteristic brushlike appearance ofthose on other members of the genus. These two differences, however,suggest that the structure, in the group to which the Eniwetok speci-men belongs, is of a primitive nature.In spite of these differences, the specimen is placed in the genusPseudotaeniacanthus not only because the characteristics, other thanthe above, coincide most closely with those previously described forother members of the genus but also because there is an overall simi-larity of the postantennal process of the Eniwetok specimen with thatof the other members. Family PandaridaePandarus cranchii LeachPandarus cranchii Leach, 1819, p. 535.?Lewis, 1966, p. 81, figs. 10-13.?Cressey,1967, p. 9, figs. 27-33.For remaining synonymy, see Lewis (1966) and Cressey (1967).Hosts and distribution.?See Lewis (1966).Material.?4 females (USNM 120746) from the external surfaceof Galeocerdo cuvieri (Lesueur).Measurements (in mm).?4 females:Length of body, excluding caudal setaeLength of cephalothorax, including frontal regionWidth of cephalothoraxLength of genital segmentWidth of genital segmentLength of caudal ramiLength of anal laminaLength of egg strings (6 strings)Description.?See Lewis (1966).
mean
16 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125Family DissonidaeDissonus heronensis KabataFigures 7-9Dissonus heronensis Kabata, 1966a, p. 221, fig. 5.Host and distribution.?"Unspecified fish of the family Balisti-dae" (Kabata, 1966a, p. 221), Heron Island, Queensland, Australia.Material.?7 females and 1 male (USNM 120741) from the gillcavity of Balistoides viridescens (Bloch and Schneider)
.
Measurements (in mm).?5 females and 1 male:emale
COPEPODS?LEWIS 17
Platelike formation of cuticle covering most of dorsal surface, ventralsurface with 2 series of nodules, each nodule bearing bifid hairlikeprojections, anterior series consisting of transverse row of 4 nodules,second series usually forming longitudinal row of 3 nodules on each
Q05 mm. 9cr 0.1 mm Q(fFigure 7.
?
Dissonus heronensis Kabata, 1966, dorsal views: a, male; h, female. Ventralviews: c, male genital segment; d, female genital segment; e, female first, second, and thirdpedigerous segments (P-I, II, HI);/, right caudal ramus; g, right antennule and adjacentfrontal region.283-932?68 2
18 PROCEEDINGS OF THE NATIONAL MUSEUM
side although nodules not always in row. Fifth leg (fig. 9e) situatedon lateral ventral surface in posterior half of segment, consisting ofpalp bearing 4 plumose setules, Abdomen 1-segmented, distinctly-separable from genital segment. Lateral margins, in adult, irregular,anterior surface broader than posterior. Posterior surface flat laterally,broadly bilobed medially, junction of lobes forming anal indentation.Caudal rami (fig. 7/) small, subrectangular, with 3 plumose terminalsetae, 1 plumose setule on inner distal surface, and plumose seta andsetule on proximal lateral surface.Male cephalothorax and free psdigerous segments similar to thoseof female (fig. 7a). Genital segment (fig. 7c) elongate, rounded an-
d 0.1 mm. cf 0.1 mm. 9Figure 8.
?
Dissonus heronensis Kabata, 1966, ventral views: a, female oral region, showingantenna, mouth cone, mandible, maxillule, maxilla base (ma-2), postantennal processand postoral process; b, male left antenna and postantennal process; c, right maxilla;d, male left maxilliped; e, female left maxilliped.
NO. 3656 COPEPODS?LEWIS 19
teriorly, tapered slightly posteriorly; process-bearing nodules presentalthough longitudinal row extending posterolaterally, consisting of 4nodules, not 3 as in female. Fifth leg (fig. 9/) situated on lateralventral surface, consisting of 5 lightly plumose setules originatingfrom slight swelling. Sixth leg (fig. 9^) lappet-shaped, situated onlateral posterior surface of segment, bearing 2 lightly plumose setules.Abdomen 1-segmented, short; narrow anteriorly, flared sharplyposteriorly, posterior surface as in female. Caudal rami as in female.Female and male antennule (fig. 1g) 2-segmented, situated on lateralanterior ventral surface of cephalothorax and adjacent frontal region.Second segment approximately nine-tenths the length of first; firstbroader proximally than distally, lateral margins irregular; anteriorventral surface of first segment bearing approximately 28 lightlyplumose setae and setules. Second segment rodlike, medial posteriorsurface with one naked setule, distal surface with 12 naked setides.Female antenna (fig. 8a) 3-segmented, situated posterior and medialto antennule base. First segment subrectangular, attached to heavilysclerotized padlike projection of cephalothorax. Second segment sub-rectangular, slightly longer than first segment. Third segment in-completely fused to clawlike terminal process, with setule-like acces-sory process proximally. Segments of male antenna (fig. 86) similarto those of female although second with slight indication of adhesionsurfaces (not shown in figure), terminal process of third segment withaccessory claw proximally, segment with second accessory process atindistinct junction with terminal process.Female and male mandible (fig. 8a) 4-parted, distalmost partflattened, inner margin with 10-12 denticulations. Female and malepostantennal process (figs. 8a, h) situated posterior and slightly lateralto antenna base, consisting of 3 minute nodules, each with one or morehairlike processes. Female and male postoral process consisting of long,spatulate spine, male spine with light, spinelike accessory processdistally. Female and male maxillule (fig. 8a) situated immediatelylateral to mouth cone base, consisting of lobate projection, formingbase of postoral process, bearing nodule, with seta and 2 setides, onproximal outer surface. Projection with slight adhesion surface ondistal half of outer surface. Female and male maxilla (fig. 8c) 2-seg-mented, situated lateral and slightly posterior to maxillule. Segmentlengths about equal, first more strongly developed, second rodlike,Avith small membrane on distal inner surface and 2 saber-shapedterminal processes. Innermost terminal process approximately oneand one-half times the length of outermost, both with fine membranes,distal portion of membranes forming denticidations on innermostterminal process.
20 PROCEEDINGS OF THE NATIONAL MUSEUMFemale maxilliped (fig. 8e) 2-segmented, situated immediatelyposterior and medial to maxilla base. First segment irregular, strongly-developed, proximal end fused with cephalothorax; large, shelflikeprojection present on proximal inner surface, receiving distal end ofsecond segment terminal process when segment flexed. Second segmentindistinctly separable from clawlike terminal process, with accessory
0.05 mm. 9 0.05 mm. 0*Figure 9.
?
Dissonus heronensis Kabata, 1966, right thoracic legs, anterior views: a, first;b, second; c, third, d, fourth. Legs, ventral views: e, female right fifth; /, male rightfifth; g, male left sixth.
COPEPODS?LEWIS 21processes. Male maxilliped (fig. 8d) similar to that of female exceptshelflike projection of first segment much smaller.For natm-e of thoracic legs and armature, see figm-es Qa-d and table 4.Discussion.?The male specimen from Eniwetok differs slightlyfrom the description given by Kabata (1966a) for the male specimenfrom Heron Island. The differences are in some of the armatureelements on the thoracic legs and include the absence, on the Eniwetokspecimen, of a small denticulation on the second segment of the endo-podite of the first leg and the presence of a coarsely frilled membraneinstead of 3 spinules on the second segment of the exopodite of thefirst thoracic leg.Table 4.?Armature of thoracic legs I-IV of the female and male of Dissonus heronen-sis Kabata, 1966
Leg
mean
COPEPODS?LEWIS 23plumose, spinelike process. Abdomen 1-segmented, distinct fromgenital segment, lateral margins flatly convex, posterior surfacebiconcave. Caudal rami (fig. lOh) subrectangular, bearing 3 plumosesetae and 1 plumose setule distally as well as plumose seta and setulefrom proximal half of outer surface; inner surface of rami ovoid.Male cephalothorax and free pedigerous segments (fig. 106) similarto those of female. Genital segment (fig. 10c) barrel-shaped, with
0.05 mm. 9e
Figure 10.
?
Dissonus similis Kabata, 1966, dorsal views: a, female; b, male. Ventralviews: c, male genital segment; d, female genital segment; e, processes on female genitalsegment;/, ocular region (dorsal view); g, first, second, and thiixl pedigerous segments; h,caudal ramus.
24 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125
approximately 30 bifid spines on ventral surface. Fifth leg (fig. 12g)situated on posterior medial lateral surface, consisting of slight inden-tation bearing 3 plumose setules and single naked, spinelike projection.Sixth leg (fig. I2h) situated on small projection of ventral lateralposterior surface, consisting of 3 plumose setules. Abdomen short,1-segmented, slightly wider posteriorly than anteriorly. Caudal ramias in female.Female and male antennule (fig. 11a) 2-segmented, situated onlateral anterior ventral sm"face of cephalothorax and adjacent portionof frontal region. Second segment approximately three-fourths thelength of first, first clubshaped, bearing approximately 26 lightlyplumose setules (plumosites not shown in figure) on anterior andanterior ventral surface. Second segment rodlike, with 1 naked setuleon medial posterior surface and 12 on distal surface. Female antenna(fig. 116) 3-segmented, situated posterior and slightly medial toantennule base. First segment dactyliform, attached to padlikeprojection of cephalothorax. Second segment subrectangular, ap-proximately the same length as first segment. Third segment incom-pletely fused to clawlike terminal process, bearing single, setule-likeaccessory process. First and second segments of male antenna (fig.lie) similar to those of female except second with small, earshapedarea of heavy sclerotization on distal posterior surface. Third segmentfused to clawlike terminal process, accessory processes consisting ofspinelike secondary claw and 2 naked, setule-like structures.Female and male mandible (fig. 116) 4-parted, distalmost partflattened, inner margin with 12 denticulations. Female postantennalprocess (fig. 116) situated posterior and slightly lateral to antennabase, consisting of 3 minute nodules, each appearing to have severalhairlike processes. Male postantennal process (fig. lie) consisting of2 nodules (posteriormost of female not visible on male), each withseveral hairlike processes. Female and male maxillule (fig. 116)situated immediately lateral to mouth cone base, consisting of 3naked setules appearing to arise directly from lobate projection fittingover knoblike extension of cuticle. Lobate projection bearing elongate,slightly curved spine forming postoral process, spine with minutenodule on distal inner surface. Lobate projection and spine withoutdistinct indication of adhesion surface on either male or female.Female and male maxilla (fig. lid) 2-segmented, situated lateral andslightly posterior to maxillule. Second segment slightly less thanthree-fourths the length of first (including articulation and muscleattachment surface at proximal end of first). First segment sub-rectangular, more strongly developed than second, second rodlike,w^th pair of denticulated membranes in distal half and pair of saber-shaped terminal processes. Innermost terminal process approximately
COPEPODS?LEWIS 25twice the length of outermost, both with fine membranes, membranesextending to tip of innermost terminal process, forming complexseries of denticulation (fig. ll^;).Female and male maxilliped (fig. 11/) 2-segmented, situated im-mediately posterior and medial to maxilla base. First segment strongly-developed, with long, recurved articulation and muscle attachmentsurface embedded in cephalothorax; inner surface with large, shelflikeprojection, projection (fig. 11^) bearing 2-parted nodule, distal partspherical, with approximately 3 ridges forming roughened surface.Second segment distinct from clawlike terminal process, bearingsingle, minute, setule-like accessory process; terminal process withfine, longitudinal ridges distally.
0.2 mm. 9 d" 0.2mm.9c^Figure 11.
?
Dissonus similis Kabata, 1966, ventral views: a, left antennule; b, female oralregion showing antenna, postantennal process, mouth cone, mandible, maxillule, postoralprocess, and maxilla base; c, male right antenna and postantennal process; d, right maxilla;e, distal region of innermost terminal process of maxilla; /, left maxilliped; g, shelflikeindentation on first segment of maxiUiped.
26 PROCEEDINGS OF THE NATIONAL MUSEUMFor nature of thoracic legs and armature see figures 12a-e and table5. Variation present in armature of second segment of endopodite offirst thoracic leg; basic armature shown in table 5, consisting of 3setae on inner surface, 1 terminal spinelike projection and 6 more orless lobulate projections of outer surface in addition to plumositieson outer surface. Variation exhibited in number of lobulate projectionsand expressed in decrease from basic number.
O.OSmm.cfFigure 12.
?
Dissonus similis Kabata, 1966, right thoracic legs, anterior views: a, first;b, second segment of endopodite of first; c, second; d, third; e, fourth. Legs, ventralviews:/, female left fifth; g, male right fifth; h, male right sixth.
COPEPODS?LEWIS 27Discussion.?The female Eniwetok specimens differ from Kabata'soriginal description (1966a, female only) in several respects:1. The length is less than that given for D. similis by Kabata(average of 2.18 mm for the Eniwetok specimens, 2.84 mm for Kabata'stwo specimens).2. The pad associated with the maxillule is indicated by Kabata(p. 213) to have numerous delicate ridges. These were not clearly seenon the Eniwetok material although they may be visible with phasecontrast.3. The minute process figured on the distal end of the spine associ-ated with the above-mentioned pad is not visible in the Eniwetokmaterial.Table 5.
?
Armature of thoracic legs I-IV of the female and male of Dissonussimilis Kabata, 1966
Leg
28 PROCEEDINGS OF THE NATIONAL MUSEUMplatelike area of heavy sclerotization situated between and immediatelyposterior to these processes.Family EuryphoridaeAlebion gracilis WilsonFigure 13Alebion gracilis Wilson, 1905b, p. 128.?Lewis, 1966, p. 136, figs. 36-38.For synonymy, see Lewis (1966).Hosts and distribution.?See Lewis (1966).Material.?4 males (USNM 120747) from the external surface ofCarcharinus menisorrah (Miiller and Henle); 2 females (USNM120748) from the external surface of C. menisorrah.Measurements (in mm).?2 females and 4 males: malefemaleTotal length, excluding caudal setae 6. 66, 6. 55Length of cephalothorax 3. 81, 3. 59Width of cephalothorax 2. 89, 3. 07Length of genital segment 1. 63, 1. 66Width of genital segment 1. 96, 2. 00Length of genital segment processes 1. 11, 1. 18Length of abdomen 0. 70, 0. 74Length of egg strings (nonovigerous)
mean3. 622.092. 120. 760. 67
0. 56
range3. 52-3. 812. 04-2. 151. 92-2. 220. 70-0. 81(all specimens)
0. 44-0. 67
Description.?Male only (for description of female, see Lewis,1966). Male cephalothorax (fig. 13a) ovoid, consisting of cephalonand first 4 thoracic segments. Frontal region slightly less than one-tenth the total length of cephalothorax, with narrow membrane alonganterior margin; division between frontal region and rest of cephalo-thorax distinct. Lateral margins of cephalothorax smoothly convex,bearing narrow membrane. Posterior lateral region with small, semi-lunar concavity, concavity with fine, hairlike process. Posterior mediancephalothoracic region terminating at level of posterior lateral regions,posterior margin flatly concave medially, posterior surface bearingapproximately 5 spinules laterally. Posterior sinus U-shaped, withfrilled membrane and shelflike projection extending medially fromouter surface, second membrane extending posteriorly from posteriorouter surface. Dorsal surface with major grooves forming irregidarH, anterior longitudinal legs of H terminating lateral to distinctocular region. Median dorsal surface with 3 pairs of spines situatedbetween ocular region and cross bar of H formed by major dorsalgrooves. Free fourth pedigerous segment short, length approximatelyone-third the width, dorsal surface with small, platelike lateral ex-
COPEPODS?LEWIS 29
0.4 mm. d" 0.1 mm. cr 0.05 mm. cTFigure 13.
?
Alehion gracilis Wilson, 1905, male: a, dorsal view; h, genital segment, ventralview; c, right antenna, ventral view; d, right maxilliped, ventral view; e, distal region ofsecond segment of exopodite of right first thoracic leg, anterior view; /, exopodite ofsecond thoracic leg, anterior view; g, right fifth leg, ventral view; h, right sixth leg, ventralview.
30 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125tensions, each with approximately 4 spinules posteriorly. Divisionbetween fourth pedigerous and genital segments distinct, complete.Male genital segment (fig. 136) with convex lateral margins an-teriorly, tapered posteriorly. Anterior and posterior halves each withcluster of spinules and spines laterally. Posterior margin flat dorsaUy,bilobed ventrally. Fifth legs (fig. 13g) situated at break betweenanterior and posterior halves, consisting of node bearing 3 nakedsetules. Sixth legs (fig. ISh) situated on posterior end of lobe onventral surface, consisting of 3 naked setides. Abdomen, 2-segmented,distinct from genital segment. First segment subrectangular, ap-proximately five-eighths the length of second segment, medial lateralsurfaces with cluster of spines and spinules. Second segment con-tinuous with caudal rami, slightly wider posteriorly than anteriorly,anal indentation distinct. Caudal rami subrectangular plumosealong distal inner siu-face. Rami bearing 3 plumose terminal setae,1 plumose seta on lateral distal surface, and 2 plumose setules, firston distal inner surface, second just medial to outermost seta. Outersiu-face of rami mth several minute spinules.Male antennule similar to that of female although second segmentapproximately half the length of first, not one-third as in female.Antenna (fig. 13c) 3-segmented, situated posterior and medial toantennule base. First segment u-regular, with ridgelike adhesion processproximally. Second segment clubshaped, with 2 knoblike adhesionprocesses on distal outer surface, anteriormost continuous withspikeshaped projection. Third segment continuous mth clawliketerminal process, with node proximally bearing weakly sclerotized,spinelike projection; setulelike accessory process present at probablejunction of segment and terminal process. Terminal process withsecondary spine proximally.Mandible, maxillide, maxilla, postantennal process and postoralprocess similar to those of female. Maxilliped (fig. 13d) 2-segmented,situated posterior and medial to maxilla base. First segment stronglydeveloped, with narrow, somewhat recurved proximal articulationprocess. Distal inner surface of first segment wdth serrated ridgeforming adhesion process. Second segment incompletely separablefrom clawlike terminal process, bearing setalike accessory processfrom distal inner surface.Thoracic legs I-IV similar to those of female. Two major differencesevident. Innermost terminal spine of second segment of exopodite ofmale first leg bifid (fig. 13e), female with simple spine. Spine on outerdistal surface of second segment and spine on proximal outer surfaceof third segment of exopodite of male second thoracic leg (fig. 13/),with denticulations, not enlarged and hookshaped as in female.
NO. 3656 COPEPODS?LEWIS 31Family CaligidaePseudanuretes pomacanthi, new speciesFigures 14, 15Material.?1 female (holotype, USNM 120749) from the gillcavity of Pomacanihus imperator (Bloch).Measurements (in mm).?1 female:Total length, excluding caudal setae . 97Length of cephalothorax 0.74Width of cephalothorax 0.61Length of fused genital segment and abdomen 0.23Width of genital segment 0.31Length of egg strings (strings broken)Description.?Cephalothorax (fig. 14a) consisting of cephalon andfirst 4 thoracic segments, anterior end blmitly pointed. Frontalregion narrow, forming approximately one-sixteenth the length ofcephalothorax, partially covered by adjacent portion of cephalothorax;with narrow membrane projecting from anterior ventral surface.Lateral surfaces of cephalothorax flatly convex, with fine, ventrallyprojecting membrane. Posterior lateral regions forming narrow,slightly projecting lobe, posterior sinus minute, without membrane.Posterior median cephalothoracic region broad, forming 90 percentof posterior surface, covering indistinct free fourth pedigerous segmentand anterior end of genital segment. Major dorsal cephalothoracicgrooves extending anteriorly from junction of posterior lateral andposterior median cephalothoracic regions, terminating on lateralsurface in anterior third of cephalothorax; transverse groove absent.Ocular region distinct, situated well anterior to termination of dorsalgrooves.Free fourth pedigerous segment appearing as narrow annulus,indistinctly separable from cephalothorax but distinct from genitalsegment. Genital segment (fig. 145) broad, lateral surfaces convex,posterior surface knobby, depressed medially. Fifth legs (fig. 15/)situated on posterior lateral surface, consisting of 4 plumose setules,1 slightly anterior to other 3. Abdomen fused with genital segment,situated in posterior depression of segment. Anal opening distinct,between small caudal rami. Caudal rami (fig. 14c) short, bearing 4plumose terminal setae.Antennule (fig. 14c?) 2-segmented, attached to cephalothorax im-mediately lateral to frontal region; segments flaccid, poorly sclerotized.First segment approximately one and one-half times the length ofsecond, margins irregular, anterior ventral surface bearing approxi-mately 13 naked or lightly plumose setae, distal ventral surface bearing
32 PROCEEDINGS OF THE NATIONAL MUSEUM
0.1 mm. ij 0.1 mm. 9Figure 14.
?
Pseudanuretes pomacanthi, new species, female: a, dorsal view; c, caudal rami,same view. Ventral views: h, genital segment, right side; d, right antennule and adjacentsection of frontal region; e, oral region, left side showing antenna, mouth cone, mandible,maxillule, maxilla base (ma-2), and associated processes, adhesion pad (ad), and maxillipedbase (mxpd);/, left maxilla; g, left maxilliped.
NO. 3658 COPEPODS?LEWIS 333 setae. Second segment rodlike, with single naked setule from middleof segment, approximately 9 naked setules from distal sm*face.Antenna (fig. 14e) 3-segmented, situated posterior and slightly medialto antenniile base. First segment generally ringshaped, heavilysclerotized, with spikelike projection from posterior sm-face. Secondsegment well developed, broader proximally than distally. Thirdsegment and clawlike terminal process continuous, with knoblikearticulation surface proximally and knoblike projection on medial innersurface; accessory processes not evident.Mandible (fig. 14e) 4-parted, rodlike, distalmost part denticulatedalong inner margin. Postantennal process evident as small, lightlysclerotized area surrounded by ringlike area of heavy sclerotizationsituated lateral and posterior to antenna base, area with 3 nodule-likestructures although "typical" hairlike processes not evident. Postoralprocess absent. Postoral adhesion pad present as barshaped projectionof heavily sclerotized rod in sternal region, immediately anterior tomaxilliped base. Maxillvde (fig. 14e) minute, nodular, situated lateraland posterior to mouth cone, slightly posterior to antennal base.Nodule bearing 2 poorly sclerotized, naked setae. Maxilla (fig. 14/)2-segmented, situated posterior and lateral to maxillule, adjacent to(though not associated with) large, naked seta (maxillary whip ofKabata, 1965b). First segment approximately one and one-fourthtimes the length of second, elongate, tapered to minutely bilobedproximal articulation process. Second segment elongate, with small,spikelike subterminal process and long, setalike terminal process.MaxilUped (fig. 14^) 2-segmented, situated medial and slightlyposterior to maxilla base. First segment well developed, proximal endnarrow, reciu-ved slightly. Second segment incompletely separablefrom clawlike terminal process, accessory process not evident. Sternalfurca absent.Thoracic legs I-III biramous although endopodite of first legrudimentary, fourth thoracic leg uniramous, small, poorly sclerotized,3-segmented. For nature and armature of thoracic legs, see figuresI5a-e and table 6.Discussion.?The female of Pseudanuretes pomacanthi, new species,differs from the females of the two other recognized members of thegenus, P. chaetodontis Yamaguti (1936) and P. fortipedis Kabata(1965b) (for a note on P. schmitti Rangnekar, 1957, see below), intwo respects:1. The antenna is simple and does not have an accessory spine.2. The structure and armature of the fourth thoracic leg. The legof P. pomacanthi is similar in structure to that of P. fortipedis but has2 terminal setae instead of 1 The leg of both species is either 2- or3-segmented while that of P. chaetodontis is only 1-segmented.28a-932?68 3
34 PROCEEDINGS OF THE NATIONAL MUSEUMKabata (1965b, p. 30) questions the inclusion of P. schmittiRangnekar (1957) in the genus Pseudanuretes because of the presenceof postantennal processes as well as the apparent absence of a maxillarywhip. Whether the species belongs to the genus Pseudanuretes or
/ t I I I I >0.1 mm. ^Figure 15.
?
Pseudanuretes pomacanthi, new species, female, thoracic legs: a, right first,posterior views; b, right second, anterior view; c, right third, posterior view; d, rami ofright third, posterior view; e, left fourth, ventral view;/, right fifth, ventral view.
COPEPODS?LEWIS 35somewhere else can only be determined after the type material isreexamined.There are several unique characteristics found in P. pomacanthiand, to some extent (reference to endopodite of second thoracic legand to third thoracic leg), in P. chaetodontis (and presumably in P.fortipedis) which suggest a change from the general makeup of othercaligids
:
1. The second thoracic leg, which the present author believes isone of the more stable "elements" in caligids, lacks several armatureelements in P. pomacanthi ("m," "p," and "s" on the protopodite;
"c" on the inner surface of the second segment of the endopodite).2. The third thoracic leg, which, in P. pomacanthi and P. chaetodontisTable 6.
?
Armature of thoracic legs I-IV of the female of Pseudanuretes poma-canthi, new species
Leg
mean
COPEPODS?LEWIS 37Measurements (in mm).?16 females and 1 male:female
38 PROCEEDINGS OF THE NATIONAL MUSEUM
of lateral surface, at origin of fifth legs. Fifth legs (fig. 16/) lobate,short, bearing 3 plumose setules, additional setule present just an-terior to base of lobe. Sixth legs (fig. 16^) lobate, approximatelytwice the size of fifth legs, situated on posterior ventral surface ofgenital segment, bearing 3 plumose setules. Abdomen 1-segmented,
0.2mmFigure 16.
?
Lepeophtheirus plectropomi? Nunes-Ruivo and P. Fourmanoir, 1956, dorsalviews; a, female; b, male. Ventral views: c, female genital segment and fifth leg;d, male genital segment, fifth, and sixth legs. Legs, ventral views: e, female fifth;/, malefifth; g, male sixth.
COPEPODS?LEWIS 39
short, length and width about equal, flared slightly towards posteriorend. Caudal rami as in female.Female and male antennule (fig. 17a) 2-segmented, first segmentstrongly developed, approximately one and one-half times the lengthof second. Irregular articulation surfaces on proximal end of first
0.2 mmFigure 17.
?
Lepeophtheirus plectropomP. Nunes-Ruivo and P. Fourmanoir, 1956, ventralviews (except b): a, left antennule; b, process on distal posterior surface of first segment ofmale antennule; c, female left antenna; d, male right antenna; e, left mandible; /, post-antennal process; g, female left maxillule and postoral process; h, male oral region, showingmouth cone, mandible, maxillule, postoral process, and postoral adhesion pad; i, leftmaxilla; /, left maxilliped.
40 PROCEEDINGS OF THE NATIONAL MUSEUM 'fol. 125segment articulating on platelike process extending posteriorly fromfrontal region, terminating in cephalothorax posterior to frontalregion. Anterior ventral and anterior lateral surfaces of first segmentbearing 24 plumose setae and se tides, bifurcate process (fig. 176)present on posterior edge of distal surface. Second segment elongate,bearing single naked seta from middle of posterior surface, 12 nakedsetae from distal surface. Female antenna (fig. 17c) 3-segmented,situated posterior and medial to antennule base. First segment broad,irregular, bearing spikelike projection on inner posterior surface.Second segment short, well developed. Third segment and terminalprocess indistinctly separable or continuous, clawlike, seta-likeaccessory process present at indistinct junction of segment and ter-minal process. Male antenna (fig. 17d) 3-segmented, positioned as infemale. First segment elongate, with large adhesion surface ventrally;length of second segment approximately the same as first, segmentwell developed, with several irregular, spikelike projections and 2adhesion surfaces, one on anterior medial region, second on broad,irregular projection of inner medial region. Third segment distinctfrom bifurcate terminal process, bearing single seta-like accessoryprocess on inner surface, at junction of segment and terminal process.Mandible of female and male (fig. 17e) 4-parted, rodlike, distalmostpart curved inward, flattened, bearing 11-12 denticulations. Femaleand male postantennal process (fig. 17f) situated lateral and slightlyposterior to antenna base, consisting of spikelike projection and 3nodules, each bearing several hairlike processes. Two nodules presenton base of spikelike projection, third situated immediately posteriorto base. Female postoral process (fig. 17^) consisting of bifurcateprojection immediately posterior to maxillule, male process (fig. 17h)spikeshaped, with poorly sclerotized accessory spine from distal halfof inner ventral surface. Female and male maxdlule (figs. 17g,h)consisting of nodule bearing 3 seta-like processes. Female and malemaxilla (fig. 17i) 2-segmented, situated lateral and slightly posteriorto postoral process. Both segments elongate, first approximatelyfour-fifths the length of second. Rodlike second segment with 2membranes on medial inner surface (one folded, appearing spinelike)and 2 saber-like terminal processes, innermost slightly more thantwice the length of outer, with frilled membrane along both margins,outermost process with frilled membrane on outer margin only.Male with lobate postoral adhesion surface (fig. 17h), surface similarto adhesion surface on first segment of antenna although plates not asdistinct.Maxilliped of female and male (fig. 17j) 2-segmented, situated pos-terior and medial to maxilla base. Fu*st segment strongly developed,length slightly more than one and one-half times that of combined
COPEPODS?LEWIS 41
second segment and terminal process. Second segment continuouswith clawlike terminal process, bearing single, seta-like accessoryprocess on inner surface, at junction of segment and terminal process.Female and male sternal furea situated between and slightly posterior
Figure 18.
?
Lepeophtheirus plectropomP. Nunes-Ruivo and P. Fourmanoir, 1956, thoraciclegs, anterior views: a, right first; b, distal region of second segment of exopodite of first;
c, portion of median terminal spine of second segment of exopodite of first; d, right second;e, right third;/, right fourth; g, enlarged portion of denticulated region of fourth- h, jointof protopodite and first segment of exopodite of fourth.
42 PROCEEDINGS OF THE NATIONAL MUSEUMto maxilliped bases, tines angled outward slightly, bluntly pointeddistally. Basal region of furca with lateral projection on each side,length of projections variable although projection on left usuallylonger than that on right.Thoracic legs I-III biramous although endopodite of first legrudimentary, fourth thoracic leg uniramous, 4-segmented. For natureof appendages and armature, see figures 18a-;; and table 7.Discussion.?The identification of the Eniwetok specimens asL. plectropomi is questioned for three reasons:1. The incomplete original description makes identification difiicult.2. The rami of the sternal furca of the Eniwetok specimens arethinner than those figured for L. plectropomi.3. The membrane on the inner 2 terminal spines on the secondsegment of the exopodite of the first thoracic leg is figured as reachingTable 7.
?
Armature of thoracic legs I-IV of the female and male of Lepeophtheirusplectropomi? Nunes-Ruivo and Fourmanoir, 1956
Leg
NO. 3656 COPEPODS?LEWIS 43
2. The antenna of the adult male of L. plectropomi (providing theEniwetok specimens are members of this species) has several spinelikeprojections on the second segment. The antenna of the adiilt male ofL. dissimulatus does not have these. The only projecting process onthe antenna of this species is a dactyliform adhesion process thatusually is \vrapped around the distal portion of the segment.Lepeophtheirus dissimulatus WilsonLepeophtheirus dissimulatus Wilson, 1905, p. 631, pi. 22.?Lewis, 1964a, p. 178,figs. 11, 12.Hosts and distribution.?See Lewis (1964a, 1967).Material.? 1 female (USNM 120752) from the gill cavity ofParupeneus cyclostomus? (Lac^pede).Measurements (in mm).?1 female:Total length, excluding caudal setae 2. 38Length of cephalothorax 1. 75Width of cephalothorax 1. 62Length of genital segment 0. 58Width of genital segment 0. 83Length of abdomen 0. 14Length of egg string (1 string) 1. 75Description.?See Lewis (1964).Pseudocaligus similiSf new speciesFigures 19-21Material.?1 female (holotype, USNM 120753) from the gillcavity of Fistularia petimba Lacepede; 1 male (allotype, USNM120754) from the gill cavity of F. petimba; 1 male (paratype, USNM120755) from the gill cavity of F. petimba; 7 females (2 damaged)(paratypes, USNM 120756) from the buccal cavity of F. petimba;8 females and 5 males (retained by author) from the gill cavity ofF. petimba.Measurements (in mm).?14 females, 5 males:
females males
44 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125Description.?Female cephalothorax (fig. 196) ovoid, consistingof cephalon and first 4 thoracic segments. Frontal region approximatelyone-eleventh the total length of cephalothorax, anterior surfacebilobed, with membranous margin; division between frontal regionand remaining cephalothorax incomplete. Lunules (fig. 19^) distinct,extending posteriorly, on ventral surface, to posterior portion offrontal region. Lateral cephalothoracic margins irregular, with narrowmembrane extending laterally, second membrane extending medially,on ventral surface. Posterior lateral regions lobate, with small,socket-like depression. Posterior sinus (fig. 19e) distinct, semi-V-shaped, with fine membrane on outer surface. Posterior mediancephalothoracic region extending slightly past lateral regions, posteriormargin irregular. Major dorsal cephalothoracic grooves forming irreg-ular H, anterior legs of H terminating in narrow bands of heavysclerotization. Ocular region distinct, just anterior to anterior end ofH -shaped groove system.Female free fourth pedigerous segment distinct from cephalo-thorax, indistinctly separable from genital segment. Approximatelength slightly more than two-thirds the width, lateral margins irreg-ularly convex. Genital segment (fig. 19d) elongate, irregularly taperedanteriorly, lateral posterior surface lobate. Fifth legs (fig. 21g) situatedon posterior lateral surface, consisting of 4 plumose setules, 2 fromnodule, remaining 2 arising from surface of genital segment adjacentto nodule.Female abdomen elongate, 2-segmented, indistinctly separablefrom genital segment. First segment more than 4 times the lengthof second, lateral margins irregular; second segment with flatlyconvex lateral margins, posterior surface concave laterally, bilobedmedially, at anal indentation. Caudal rami (fig. 19/) attached to con-cave lateral posterior surface of second segment of abdomen, shapesubrectangular, with small convex projection on distal inner surface.Armature consisting of 2 plumose setules from distal outer surface,3 plumose setae from outer distal surface, single plumose setule frominner distal surface, and plumosities on convex projection of distalinner surface.Male cephalothorax (fig. 19a) similar to that of female. Free fourthpedigerous segment slightly more than twice as wide as long, distinctfrom both cephalothorax and genital segment. Genital segment (fig.19c) wider anteriorly than posteriorly, lateral margins flatly convexin anterior half, flatly concave in posterior half; dorsal posteriorsurface projecting posteriorly slightly past junction of genital segmentand abdomen. Fifth legs (fig. 21A) situated on middle of lateralventral surface, consisting of nodule bearing 3 plumose setules. Sixthlegs (fig. 21i) situated on posterior ventral surface, slightly anterior
COPEPODS?LEWIS 45
0.2 mm. 9cf
Figure 19.
?
Pseudocaligus similis, new species: a, male, dorsal view; h, female, dorsal view;
c, male fourth pedigerous and genital segments, ventral view; d, female, same; e, posteriorcephalothoracic sinus, dorsal view;/, right caudal ramus, ventral view; g, right lunule andantennule (see text for differences between female and male), ventral view.
46 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125to genital opening, consisting of 2 plumose setules. Abdomen distinctfrom genital segment, 2-segmented, first segment approximatelythree-fourths the length of second, both segments subrectangular.Caudal rami similar to those of female although small convex projec-tion on distal inner surface more distinct in male.Female antennule (fig. 19^) 2-segmented, attached to lateral post-erior ventral surface of frontal region and adjacent ventral surface ofcephalothorax. First segment slightly less than twice the length ofsecond, broad proximally, tapered toward slightly constricted distalend, anterior ventral and anterior surface bearing 24 naked andlightly plumose setae and setules. Second segment rodlike, with singlenaked setule from middle of posterior surface, approximately 1 1 nakedsetules from distal surface. Male antennule similar to that of femaleexcept second segment longer, first segment only 1.4 times the lengthof second. Female antenna (fig. 206) 3-segmented, situated posteriorand medial to antennule base. First segment short, distal surface sub-triangular, inner posterior surface with small, spikelike projection.Second segment short, slightly wider proximally than distally. Thirdsegment continuous with clawlike terminal process, bearing 2 setule-like accessory processes, 1 proximally, 1 medially. Male antenna (figs.20a,c) 3-segmented, first segment longer than that of female, spikelikeprojection minute. Second segment longer than that of female, withone adhesion pad on proximal inner surface, another forming ridgelikeprojection from distal posterior surface. Third segment short, suborbi-cular, distinct from short, beakshaped terminal process, bearing 2setule-like accessory processes, 1 on either side of terminal process.Female and male mandible (figs. 20a,b) rodlike, 4-parted, distalmostpart flattened, curved inward, inner margin with 12 denticulations.Female and male maxillule (figs. 20a,b) palplike, situated posterior andslightly lateral to mandible base, with naked terminal setule and seta.Female and male maxilla (fig. 20d) 2-segmented, situated posterior andlateral to maxillule. First segment slightly less than half the length ofsecond, with spikeshaped projection from inner proximal surface; seg-ment curved inward slightly toward distal end. Second segment elon-gate, with small, membranous, subconical projection from distal halfof inner surface, distal surface bearing 2 seta-like processes, innermostslightly less than twice the length of outermost, wdth fine membranealong inner surface, outer terminal process w4th fine membrane alongouter margin.Female postantennal process (fig. 206) situated posterior and slightlylateral to antenna base, consisting of 3 nodules bearing several hairlikeprocesses and short, spikeshaped projection originating from round,heavily sclerotized plate. Anterior 2 nodules situated on plate, third
COPEPODS?LEWIS 47located slightly posterior and medial to plate. Plate and projection ofmale postantennal process (fig. 20a) much larger, projection falciform,process bearing nodules present on plate of female not visible on male,nodule posterior to plate of female present on male. Female and malepostoral process (figs. 20a,b) spikeshaped, situated slightly posterior tomaxillule base. Postoral adhesion pads present in male (figs. 20a,/)although not rugose, consisting of pair of heavily sclerotized, U-shapedridges on median longitudinal axis slightly posterior to maxilla bases.
Q2 mm. c^ 02 mm. 9 ^Figure 20.
?
Pseudocaligus similis, new species, ventral views: a, oral region of male,showing antenna, mouth cone, mandible, maxillule, maxilla base (ma-2), postantennalprocess, postoral process, and postoral adhesion pad; b, same of female (postoral adhesionpads missing in female); c, third segment and distal region of second segment of rightantenna of male; d, right maxilla; e, female left maxilliped; /, male postoral adhesionpads and left maxilliped; g, sternal furca.
48 PROCEEDINGS OF THE NATIONAL MUSEUMFemale maxilliped (fig. 20e) 2-segmented, situated posterior andmedial to maxilla base. Fii-st segment strongly developed, with small,ridgelike projection on medial inner surface. Second segment distinctfrom clawlike terminal process; inner surface longer than outer, withsetulelike accessory process distally. Male maxilliped (fig. 20/) similar
0.1 mm. 9 tf" 0.1 mm. 0.1 mm. (1? 0.1 mm. ccFigure 21.
?
Pseudocaligus similis, new species, right thoracic legs, anterior views (exceptf): a, first; b, distal region of second segment of exopodite of first; c, second, d, third,e, exopodite of third;/, left fourth (posterior view). Right legs, ventral views: g, female,fifth; h, male, fifth; i, male, sixth.
COPEPODS?LEWIS 49to that of female although larger and first segment bearing 3 knoblikeprojections adjacent to ridge described for female. Sternal furca(fig. 20^) U-shaped, associated with trilobate platelike structureposterior to maxilliped bases; tines of furca sharply rounded distally.For nature and armature of thoracic legs I-IV, see figures 21a-fand table 8. Second segment of exopodite of fu-st thoracic leg withonly single plumose setule on inner surface. Pair of padlike structurespresent posterior to interpodal plate of first thoracic leg.Discussion.?Pseudocaligus similis most closely resembles P.Ustulariae PUlai (1961) and P. tenuicauda Shiino (1964), both of whichare also found on Fistidaria. The similarities are not only in the overallbody shape (especially the elongate, 2-segmented abdomen in thefemale and the shorter 2-segmented abdomen in the male) but also inTable 8.
?
Arvnature of thoracic legs I-W of the female and male of Pseudocaligussimilis, new species
Leg
50 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125The species name is derived from the Latin word for "like" or
"resembling" and alludes to the similarity of P. similis to P. tenuicaudaand P. jistulariae.Caligus coryphaenae Steenstnip and LiitkenCaligus coryphaenae Steenstrup and Liitken, 1861, p. 360, pi. 4, fig. 7.?Lewis,1967, p. 101. figs. 37-39.Hosts and distribution.?See Lewis (1967).Material.?4 females and 2 males from the external surface ofEuthynniis yaito (Jordon and Evermann) ; 4 females and 1 male fromthe external surface of Sarda orientalis (Schlegel) ; 1 male from theexternal surface of Grammatorcynus bilineatus (Riippell) ; 2 femalesfrom the external surface of Caranx melampygus? Cuvier and Valen-ciennes ; 7 females and 1 male from the external surface of Katsuwonuspelamis (Linnaeus). (All specimens retained by author.)Measurement (in mm).?15 females, 5 males:females malesmeanTotal length, excluding caudalsetaeLength of cephalothoraxWidth of cephalothoraxLength of genital segmentWidth of genital segmentLength of abdomenLength of egg strings (13 strings) 4. 67 4. 22-5. 70Description.?See Lewis (1967).Remarks.?The size of the Eniwetok specimens is less than that ofthe specimens described from Hawaii. The reasons for this differencewarrant further study. One possible source for the reasons may bethat the specimens were all taken from fishes captured in the atolllagoon; no host specimens were available from the open ocean outsidethe lagoon. Caligus productus DanaCaligus productus Dana, 1853, p. 1354, pi. 94 (fig. 4).?Lewis, 1967, p. 116, figs.43-45.Hosts and distribution.?See Lewis (1967).Material.?2 females (USNM 120759) from the gill cavity ofSarda orientalis (Schlegel) ; 1 female and 2 males from the gill cavityand buccal cavity of S. orientalis; 5 females and 2 males from the gillcavity and buccal cavity of S. orientalis.
6 females, 3 males:
52 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125Description.?See Lewis (1967).Remarks.?Based on the examination of the Eniwetok material anda comparison of this material with the Hawaiian specimens (USNM112912, 112913), two additions should be made to the description inLewis (1967):1. There are 2 adhesion processes on the male antenna, the first(op. cit., p. 136) is a ridged, lappet-like adhesion pad on the distalinner sm-face of the second segment while the second (not previouslydescribed) extends, as a narrow band, from the proximal anteriorsurface to the distal inner sm-face of the second segment. This ad-hesion band is more distinct in the Eniwetok specimens than in thosefrom Hawaiian fishes.2. The positioning of the denticulations shown on the secondsegment of the endopodite of the second thoracic leg in Lewis (1967,fig. 51c) is incorrect for the appendage in situ. For detailed examina-tion and camera lucida drawings, the thoracic legs are normallyremoved and mounted under 9 mm cover slips. This technique fre-quently causes the arrangement of the denticulations on the secondsegment of the endopodite of the second thoracic leg to be distorted.In the appendage in situ, on both Hawaiian and Eniwetok specimens,the denticulations are typically arranged in pairs (except for thesingle proximalmost denticulation), straddling the outer surface ofthe segment (as shown in Kabata, 1965c, fig. 1e).Caligus ligatus LewisCaligus ligatus Lewis, 1964a, p. 164, figs. 8-9; 1967, p. 163, figs. 62-64.Hosts and distribution.?6 host records:locality hosts referenceHawaiian Islands Acanthurus dussumieriNaso hexacanthus Lewis (1964a)Dascyllus albisellaAulostomus chinensisHolocentrus xantherythrusPranesus insularumi Lewis (1967)Material.?7 females and 3 males (USNM 120764) from thebuccal cavity of Holocentrus spinirfer (Forsk?.l) ; 14 females and4 males from the buccal cavity of H. spinijer (retained by author).
COPEPODS?LEWIS 53Measurements (in mm).?19 females, 6 males:female male
locality
COPEPODS?LEWIS 55
0.2 mm. 9 0.2 mm. 9
56 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125Posterior sinus (fig. 22c) distinct, frequently closed posterly; outeriormargin bearing fine membrane, dorsal cephalothoracic surface adjacentto anterior and inner surfaces of sinus with minute, ridgelike roughen-ings. Posterior surface of median cephalothoracic region projectingslightly past posterior surfaces of lateral cephalothoracic regions,division between free foiu-th pedigerous segment and cephalothoraxdistinct. Major dorsal cephalothoracic grooves forming irregular H,anterior legs terminating well posterior to distinct ocular region presenton median longitudinal axis of body, in anterior third of cephalothorax.Free fourth pedigerous segment subtriangular, anterior regionnarrowest; medial constriction evident in some specimens, not inothers; fourth pedigerous and genital segments fused. Genital segment(fig. 226) narrow anteriorly, broad posteriorly, lateral margins stronglyconvex anteriorly, almost parallel posteriorly. Fifth leg (fig. 23g)situated on ventral posterior surface, consisting of slight swellingbearing nodule with 3 pliunose sefcules. Genital segment and abdomenfused.Abdomen 1-segmented, broad anteriorly, narrower posteriorly,lateral margins fiatly convex. Caudal rami (fig. 22d) attached toposterior ventral surface of abdomen, paddle-shaped, distal innersurface plumose. Distal surface of rami bearing 3 plumose setae and1 plumose setule, additional plumose seta and setule present onslight indentation of middle of outer lateral surface.Antennule (fig. 22g) 2-segmented, attached to knoblike cuticularprojection of lateral anterior ventral surface of cephalothorax. Firstsegment subrectangular, approximately two-thhds the length ofsecond segment, anterior ventral and anterior surfaces with 21 nakedor lightly plumose setules and setae; second segment rodlike, withnaked setule from distal third of posterior surface, 11 naked setiUesfrom distal surface. Antenna (fig. 22/) 3-segmented, situated posteriorand medial to antennule base. First segment flattened, irregularin outline; second segment subrectangular, with small, subtriangidarprojection from outer anterior surface. Third segment and terminalprocess indistinctly separable, clawUke, with setule-like accessoryprocess medially, at junction of segment and terminal process; addi-tional, lobate process present on proximal portion of segment.Mandible (fig. 22/) rodlike, 4-parted, distalmost part flattened,curved inward, with 12 denticulations along inner surface. Postanten-nal process (fig. 22/) situated posterior and lateral to antenna base,consisting of plate bearing posteriorly directed spine and shorter,medially dhected spine; 3 nodules present, 2 on plate, third slightlyposterior to plate, all with several hairlike processes. Postoral process(fig. 22/) with broad base, irregularly tapered to bifid distal end, inner-most tine approximately one-third the length of outer. Maxillule
COPEPODS?LEWIS 57
0.2 mm. 9
Figure 23.?Caligus confusus? Pillai, 1961, female, right thoracic legs, anterior views: a,first; h, distal region of second segment of exopodite of first; c, second; d, third, e, exopoditeof third;/, fourth. Left fifth leg: g, ventral view.
58 PROCEEDINGS OF THE NATIONAL RIUSEUM
(fig. 22/) nodular, situated lateral and slightly posterior to mandiblebase, bearing single naked seta and 2 naked setules. MaxiUa (fig. 22gr)2-segmented, situated lateral and slightly posterior to maxillule.First segment approximately four-fifths the length of second, taperedproximally and distally to articulation surface. Second segmentrodlike with U-shaped membrane on distal half of inner surface;distal surface v/iih 2 saber-shaped processes, innermost approximatelyone and one-half times the length of outermost, both with fine mem-branes along outer and inner margins. Postoral adhesion pads (fig.22/) evident as V-shaped ridges of heavy sclerotization adjacent tomedian longitudinal axis of body, slightly posterior to maxilla bases.Maxilliped (fig. 22^) 2-segmented, situated posterior and slightlymedial to maxiUa base. First segment strongly developed, innerTable 9.
?
Armature of thoracic legs I-IV of the female of Caligus confusus? Pillai,1961
Leg
NO. 3656 COPEPODS?LEWIS 59postoral process, and one on the outer margin of each ramus of thesternal furca. The Eniwetok specimens do not have any of thesemembranes although the edge of these structures is thin and semi-transparent and unless closely examined, gives a membrane-likeappearance,2. Pillai figures a blunt secondary projection on the proximal innerportion of the postoral process that is not present on the Eniwetokspecimens.The identification of the Eniwetok material as C. conjusus Pillai isquestioned because of the two differences mentioned above and theabsence of an adequate first description of the species.Both Pillai (1961) and Kktisinghe (1964) list Wilson's (1937a,b)and Shiino's (1959a) "Calligus constrictus" as a synonym of G. conjususbecause of the very similar morphology of the figured specimens.There are some differences in the morphology that could be consid-ered to be of a minor nature (e.g., shape of the postoral process), butthere is a difference in the size of the specimens that should be evalu-ated with sufficient material. Pillai's female specimen(s) are 2.9 mmwhile Shiino's are 3.75 mm and Wilson's 5.0 mm in length. Even thefemale specimen (s) of Kirtisinghe (1964), from Ceylon, measure 4.5mm in length, more than 1.5 times the length of PHlai's specimen (s)from southern India. Because of the difference in size, as well as theother characteristics, it is felt that there is some question (as noted inthe synonymy) about the inclusion of Wilson's and Shiino's materialand perhaps even that of Kirtisinghe.Caligus pseudokalumaif new speciesFigures 24, 25Material.? 1 female (holotype, USNM 120765) from the externalsm-face of Gymnosarea nuda Giinther.Measurements (in mm).?1 female:Total length, excluding caudal setae 2. 89Length of cephalothorax 2. 04Width of cephalothorax 1. 48Length of genital segment 0. 81Width of genital segment 0. 89Length of abdomen 0. 19Length of egg strings (strings broken)Description.?Cephalothorax (fig. 24a) ovoid, consisting of ceph-alon, maxilliped-bearing and first 3 pedigerous segments. Frontal regionapproximately one-ninth the length of cephalothorax, anterior surfacewith narrow membrane. Lunules (fig. 24g) continuous with membranealong anterior margin, extending posteriorly, on ventral surface, tojunction of frontal region and rest of cephalothorax. Lateral edge of
60 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125
cephalothorax smooth, with sUght indentation in anterior third, bearingnarrow membrane and several hairhke processes. Posterior lateralregion with small, cupshaped indentation. Posterior sinus (fig. 24c)distinct, anterior end sharply angled, lateral margins flatly concave,outer lateral surface bearing filmy membrane. Posterior median regionof cephalothorax extending posteriorly well past lateral regions, pos-terior margin flatly convex in dorsal view; pair of minute, hairlikeprojections present, slightly anterior to posterior margin. Majordorsal cephalothoracic grooves forming irregular H, posterior legsflatly convex, anterior flatly concave, cross groove extending anteriorlyfrom junction with legs of H. Ocular region distinct, in anteriorfourth of cephalothorax.Free fourth pedigerous segment distinct from cephalothorax althoughanterior half overlapped by posterior median cephalothoracic region.Fourth pedigerous and genital segments fused dorsally and ventrally.Surfaces of genital segment (fig. 246) irregular; anterior region ofsegment broad, posterior bilobed, lobes extending posteriorly to caudalrami. Fifth legs (fig. 25g) situated on ventral surface, at beginning ofposterior lobes, consisting of 2 nodules, anteriormost bearing single,lightly plumose setule, posterior bearing 2 plumose setules.Abdomen 1-segmented, distinct from genital segment, lateral mar-gins smooth, posterior margin V-shaped, almost covered by proximalsurface of caudal rami. Caudal rami (fig. 24(1) broad, lobate, widthalmost twice the greatest length. Inner surface plumose, distal surfacebearing 3 plumose setae; inner distal surface with 1 plumose setule,distal outer surface with 2 plumose setides.Antennule (fig. 24^) 2-segmented, attached to lateral posteriorventral surface of frontal region and adjacent surface of cephalothorax.First segment of general parallelogram shape, anterior and anteriorventral sm^face with 21 naked and lightly pliunose setae and setules.Second segment clubshaped, length slightly less than two-thirds thelength of anterior sm-face of first segment, with single naked seta fromdistal half of posterior surface, 13 naked setae from distal surface.Antenna (fig. 24/) 3-segmented, situated posterior and medial toantennule base. First segment squat, irregular, with narrow, dagger-like projection from posterior surface. Second segment slightly broaderproximally than distally, distal surface irregular. Third segment andterminal process continuous, clawlike, with small, setule-like accessoryprocess on proximal inner surface, second on medial surface.
Figure 2i.?Caligus pseudokalumai, new species, female: a, dorsal view; c, posterior cephalo-thoracic sinus, same view. Ventral views: b, fourth pedigerous and genital segments;d, left caudal ramus; e, left lunule and antennule;/, oral region, showing antenna, mouthcone, mandible, maxillule, maxilla base (ma-2), postantennal, and postoral processes;g, right maxilla; h, right maxilliped; i, sternal furca.
COPEPODS?LEWIS 61
0.2mm.. ? 0.2 mm. 9
62 PROCEEDESTGS OF THE NATIONAL MUSEUM vol. 125Mandible (fig. 24/) rodlike, 4-parted, distalmost part curved inwards,inner surface mth 12 denticulations. Postantennal process (fig. 24/)situated posterior and lateral to antenna base, consisting of heavUysclerotized clawlike projection with 2 nodules proximally, third presentjust posterior to base of projection; nodules each bearing single, large,hairlike process. Postoral process (fig. 24/) dagger-like, immediatelyadjacent to maxUlule. Maxillule (fig. 24/) situated lateral and slightlyposterior to mouth cone base, consisting of node bearing 2 short andone long seta-like projections. Maxilla (fig. 24^) 2-segmented, situatedlateral and slightly posterior to maxillule. First segment slightly morethan three-fourths the length of second, proximal articulation andmuscle attachment surface directed at sharp angle to axis of segment.Second segment rodlike, bearing small, horsehoe-shaped membranefrom medial inner surface and 2 saber-shaped terminal processes. Innerterminal process approximately tmce the length of outer, both withfine membrane along inner and outer surfaces.MaxUliped (fig. 24h) small, 2-segmented, situated posterior andslightly medial to maxilla base. First segment narrow, mth small,spikelike projection from proximal posterior surface. Second segmentrodlike, distinct from short, clawlike terminal process, with setule-likeaccessory process on distal inner siu-face. Sternal furca (fig. 24'i)situated on median longitudinal axis of body posterior to maxillipedbases. Basal region of furca subconical, tines flattened, chisel-shapeddistally.Thoracic legs I-III biramous although endopodite of first legrudimentary. Fourth thoracic leg uniramous, 3-segmented. For na-ture and armature of legs, see figures 25a-/ and table 10.Discussion.?Caligus pseudokalumai most closely resembles C.kalumai Lewis (1964a) recorded from Acanthurus guttatus from theHawaiian Islands. The relatively minor differences between the twospecies include the following:1. The cephalothorax is more elongate in C. pseudokalumai, and theposterior median cephalothoracic region projects posteriorly past theposterior lateral cephalothoracic regions more than twice as far as itdoes in C. kalumai (0.36 mm to 0.16 mm). As a percent of the lengthof the cephalothorax, this equals 12 and 9 respectively.2. The postantennal and postoral processes as well as the sternalfiu-ca are bulkier and more heavily sclerotized in C. kalumai. Evenwith this, however, the 3 nodules associated with the postantennalprocess each bears a single large (in comparison with other speciesof the genus), hairlike process (not 2 as stated in Lewis, 1964a, p.175) as do those in C. pseudokalumai.3. The first segment of the endopodite of the second thoracic legbears a tuft of plumosities in C. kalumai but does not in C. pseudo-
COPEPODS?LEWIS 63
005 mm. 9
Figure 25.
?
Caligus pseudokalumai, new species, female, right thoracic legs, anteriorviews: a, first; b, distal region of second segment of exopodite of first; c, second; d, third;e, exopodite of third; /, fourth. Left fifth leg; g, ventral view.
64 PROCEEDINGS OF THE NATIONAL MUSEUIVIkalumai. The plumosities on the outer margin of the second and thirdsegments of the endopodite are heavier in C. pseudokalumai than inC. kalumai.4. The first segment of the exopodite of the fom-th leg bears afilamentous (or slightly denticulated) membrane at the base of thespme in C. pseudokalumai which is missing in C. kalumai.With one possible exception, these do not appear to be gross differ-ences and the apparent close relationship between the two speciesshould be more closely examined when larger collections are available.The single difference that may be of a relatively gross nature is thetuft of plumosities (or their absence) on the first segment of theendopodite of the second thoracic leg. This is the easiest characteristicto use in separating the two species and, because of the relativelystable nature of the second thoracic leg, may indicate more divergencethan is presently believed.
Table 10.
?
Armature of thoracic legs I-IV of the female of Caligus pseudokalumai,new species
Leg
female
66 PROCEEDINGS OF THE NATIONAL MUSEUM
shape, fifth legs (fig. 28^) situated on posterior lateral surface, con-sisting of 2 setule-bearing nodules, anteriormost ^nth single plumosesetule, posterior with 2 plumose setules; sixth legs (fig. 28^) situatedon posterior surface, adjacent to junction of genital segment andabdomen, consisting of nodule bearing 3 plumose setules. Abdomen
h ^W H-H?I 1 1 t^?I , ,
' 'lo'mm.' V ' '^ 0,3 mm. 9 03 mm. c?
1.0 mm. q)
h-*H y.0.2 fTira 0.1 mm. 9 S 0.3 mm. 2 ^Figure 26.?Caligus alaihi, new species, dorsal views: a, female; b, male; e, posteriorcephalothoracic sinus. Ventral views: c, female fourth pedigerous and genital segments;d, male fourth pedigerous, genital, and first abdominal segments;/, right caudal ramus;g, left lunule and antennule.
COPEPODS?LEWIS 672-segmented, distinct from genital segment dorsally, indistinctly-separable ventrally. Fii-st segment short, slightly more than half thelength of second, lateral margins flatly convex; second segmentconstricted anteriorly, margins parallel posterior to constriction,posterior sm'face angular, as in female. Caudal rami as in female.Female and male antennule (fig. 26g) 2-segmented, attached to bothlateral ventral surface of frontal region and lateral anterior ventralsurface of cephalothorax. First segment broad proximally, tapered tonarrow distal end, anterior and ventral anterior surface with ap-proximately 20 naked and lightly plumose setae and setides. Second
0.2 mm. cC 0.2 mrri. 9 0.2 mm. 9 d"Figure 27.?Caligus alaihi, new species, ventral views: a, female oral region, showingantenna, mouth cone, mandible, maxillule, maxilla base (ma-2), postantennal, andpostoral processes; b, male right antenna and postantennal process; c, right maxilla;d, male right maxilliped; <f, female right maxilliped; /, sternal furca.
68 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 125segment rodlike, approximately four-fifths the length of first segment,posterior surface with single naked setule distally, distal surface with12 naked setae and setules. Female antenna (fig. 27a) 3-segmented,situated posterior and medial to antennule base. First segment short,squat, outline subtriangular. Second segment subrectangular; thirdsegment and incompletely fused terminal process clawlike, with sub-conical accessory process proximally, setule-like, accessory processmedially, at indistinct division between segment and terminal process.Male antenna (fig. 276) 3-segmented, situated posterior to antennulebase. First segment elongate, fused i)roximally mth cephalothorax,angled ventrally toward distal end. Second segment well developed,broader proximally than distally, with adhesion pad on distal half ofinner surface. Third segment fused with short, bifurcate terminalprocess, tines of terminal process pointed; setule-like accessory processpresent, arising just proximal to terminal process.Female and male mandible (fig. 27a) rodlike, 4-parted, distalmostpart curved inward, flattened, inner surface with 12 denticulations.Female postantennal process (fig. 27a) situated lateral and slightlyposterior to antenna base, consisting of short, clawlike projection and3 nodules, first 2 on base of projection, third slightly posteiior tobase, all 3 with several hairlike processes. Male i)ostantennal })roc-ess (fig. 276) as in fenuile except clav.like i)rojection much longer.Female postoral process (fig. 27a) spinelike, situated immediatelyposterior to maxilkde, spine projecting from middle of base, distalend rounded. Male postoral process as in female except spine project-ing from outer portion of base. Female and male maxillule (fig. 27a)nodular, situated lateral and slightly posterior to mandible base,nodule bearing 2 short and 1 long, seta-like processes. Female andmale maxilla (fig. 27c) 2-segmented, located posterior and lateral topostoral process; both segments slender although first approximatelytwo and one-half tunes the diameter of second, length slightly morethan four-fifths that of second. Second segment rodlike, with smallflapshaped membrane on distal third of outer surface, bearing 2 saber-like terminal processes, innermost longer than outer, both with finemembrane along outer and inner margins.Female maxilliped (fig. 27^) 2-segmented, situated posterior andslightly medial to maxilla base. First segment strongly developed,with slightly recurved proximal region terminating in knoblike proxi-mal end; inner medial surface with small, shelflike projection (notshown on figure) receiving distal end of terminal process of secondsegment when segment flexed. Second segment distinct from clawliketerminal process, bearing setule-like accessory process on distal innersurface. Male maxilliped (fig. 27d) similar to that of female exceptfirst segment more strongly developed and recurved proximal end
COPEPODS?LEWIS 69
02 mm. 2 O" 0.1 mm. cf 0.1 mm. 9
P'iGURE 28.
?
Caligus alaihi, new species, right thoracic legs, anterior views: a, first; b, distalregion of second segment of exopodite of first; c, second; d, third; e, exopodite of third(posterior view);/, fourth. Legs, ventral views: g, male left fifth and sixth; h, femaleright fifth.
70 PROCEEDINGS OF THE NATIONAL MUSEUM
reduced. Female and male sternal fiirca (fig. 27/) well developed,Y-shaped, distal ends of rami rounded.Thoracic legs I-III biramous although endopodite of first legrudimentary; fourth thoracic leg unirmaous, 3-segmented. For natureand armature of thoracic legs, see figures 28a-f and table 11.Discussion.?The diagnostic characteristic of Caligus alaihi isthe combination of a 2-segmented abdomen on the male, denticulationson the second segment of the endopodite of the second thoracic leg(but not on the first segment), and the presence of only 1 plumoseseta on the inner surface of the second segment of the exopodite ofthe first thoracic leg. Of these three, the most uncommonly foundfeature in other members of the genus is the presence of a singleseta on the inner surface of the second segment of the exopodite ofTable 11.
?
Armature of thoracic legs I-IV of the female and male of Caligusalaihi, new species
Leg
NO. 3656 COPEPODS?LEWIS 71
is not disfcriuible from the single female in the collection of copepodsfrom Eniwetok fishes.The species name is derived from the Hawaiian name, "alaihi," forseveral of the holocentrid fishes, the family to which the host of thiscopepod belongs.
Caligiis laticaudus ShiinoFigures 29, 30Caligus laticaudus Shiino, 1960, p. 482, figs. 5, 6.?Pillai, 1961, p. 91, fig. 3.?Yamaguti, 1963, p. 55, pi. 68, fig. 4.Hosts and distribution.?3 host records:locality liost referenceJapan Pagrosomus major Shiino, 1960South India Polynemus heptadactylusRhahdosargus sarba Pillai, 1961Material.? 1 female (USNM 120769) from the external surface ofAcanthurus olivaceous Bloch and Schneider.]\Ieasurements (in mm).? 1 female:Total length, excluding caudal setae 2. 46Length of cephalothorax 1. 24Width of cephalothorax 1-21Length of genital segment 0. 56Width of genital segment 0. 72Length of abdomen 0. 41Length of egg strings (not present, condition suggests specimen animmature adult)Description (female only).?Cephalothorax (fig. 29a) ovoid, con-sisting of cephalon, maxilliped-bearing and first 3 pedigerous segments.Frontal region approximately one-ninth the length of cephalothorax,with narrow membrane along anterior margin. Lunules (fig. 29e)distinct, extending posteriorly, on ventral surface, to posterior por-tion of frontal region, of relatively simple construction in comparison^nth those of Caligus coryphaenae. Division between frontal regionand rest of cephalothorax distinct. Lateral margin of cephalothoraxflatly convex, bearing single, narrow membrane extending laterally;posterior lateral surface lappet-shaped, ^^dth small, cupshaped in-dentation bearing 2 clusters of hairlike processes. Posterior sinus(fig. 29c) U-shaped, with membrane along outer margin. Medianposterior surface of cephalothorax extending slightly past lateralposterior surfaces, posterior margin irregular on single specimen incollection. Major dorsal cephalothoracic grooves forming u-reg-ular H,anterior legs of H terminating well posterior to ocular region. Ocularregion distinct, in anterior third of cephalothorax.
72 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 12.-.
0.1 mm. 9Figure 29.
?
Caligus laticaudus Shiino, I960, female: a, dorsal view; d, right caudal ramus,same view. Ventral views: b, posterior region of genital segment and adjacent surface ofabdomen, showing fifth leg and attached spermatophore; c, posterior cephalothoracicsinus; e, left lunula and antennule;/, oral region, showing antenna, mouth cone, mandible,maxillule, maxilla base (ma-2), postantennal, and postoral processes; g, right maxilla; h,left maxilliped; ;", sternal furca.
Nc. 3656 COPEPODS?LEWIS 73Free fourth, pedigerous segment distinct from cephalothorax,indistinctly separable from genital segment; segment widest medially,at junction with fourth thoracic legs, tapered anteriorly and poster-iorly. Genital segment (fig. 296) subovoid, posterior region irregularin single available specimen. Fifth legs (fig. 30g) situated on posteriorlateral surface of segment, consisting of node bearing 2 or 3 plumosesetules (2 present on specimen, indication of additional broken setule)and nodule bearing single plumose setule (== sixth leg of Shiino,1960, p. 485).Abdomen indistinctly 2-segmented, distinct from genital segmentventrally, indistinctly separable dorsally. First segment with flatlyconvex lateral surfaces, second tapered slightly to posterior surface.Division between segments consisting of break in cuticle of lateralregions only, muscle-segment associations not distinct enough toindicate segmentation. Caudal rami subpalmate, bearing 3 plumosesetae and 1 plumose setule distally, plumose seta and setule presenton distal half of outer lateral surface; distal half of inner surfaceplumose.Antennule (fig. 29e) 2-segmented, attached to anterior lateralventral surface of cephalothorax and adjacent surface of frontalregion. First segment approximately twdce the length of second,broad proximally, tapered distally; anterior surface sharply angleddistally. First segment bearing approximately 22 lightly plumose andnaked setae and setules. Second segment rodlike, bearing single nakedsetule from distal half of posterior surface, 1 1 naked setae and setules(including 1 bifurcate seta) distally. Antenna (fig. 29/) 3-segmented,situated posterior and slightly medial to antennule base. First segmentsquat, subtriangular from ventral viewpoint; second segment welldeveloped, broad proximally, tapered slightly to distal end. Thirdsegment and terminal process fused, with falciform outline; single,setule-like accessory process present on node at proximal end of fusedsegment and terminal process.Mandible (fig. 29/) rodlike, 4-parted, distalmost part curved inward,flattened, inner surface with 12 denticulations. Postantennal process(fig. 29/) situated lateral and slightly posterior to antenna base, con-sisting of spikelike projection and 3 nodules bearing '^everal hairlikeprocesses. Projection arising from small, subtriangular, heavilysclerotized plate, plate also bearing 2 of 3 nodules, third nodule immedi-ately posterior to plate. Postoral process (fig 29/) spinelike, curving out-ward slightly. Maxillule (fig. 29^) nodular, situated immediately anteri-or to postoral process, nodule bearing 1 long, 2 short, naked seta-likeprocesses. Maxilla (fig. 29^) 2-segmented, situated immediatelyposterior and slightly lateral to postoral process. First segment ap-proximately nine-tenths the length of second, second elongate, with
74 PROCEEDINGS OF THE NATIONAL MUSEUM
0.05 nnm. 9
Figure 30.
?
Caligus lalicaudus Shiino, 1960, female, right thoracic legs: a, first, anteriorview; b, distal region of second segment of exopodite of first, anterior view; c, second,posterior view; d, third, anterior view; e, exopodite of third, posterior view; /, fourth,posterior view. Right fifth leg: g, ventral view.
COPEPODS?LEWIS 75fine membrane on distal half of outer surface, distal surface bearing 2saber-shaped processes, innermost approximately one and one-fourthtimes the length of outermost, both fringed with fine membrane.Maxilliped (fig. 20^) 2-segmented, situated posterior and slightlymedial to maxilla base. First segment strongly developed, irregular inoutline; widest medially, proximal end narrow, distal approximatelyhalf the greatest width; segment with socket-like shelf on medial innersurface, receiving distal end of second segment terminal process whensegment flexed. Second segment distinct from clawlike terminalprocess, bearing setule-like accessory process on distal inner surface.Sternal furca (fig. 29i) situated between and slightly posterior tomaxilliped bases, bifurcations flattened anteroposteriorly, lobate inoutline.Table 12.
?
Armature of thoracic legs I-IV of the female of Caligus laticaudusShiino, 1960
Leg
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