PROCEEDINGS OF THE UNITED STATES NATIONAL MUSEUM
Issued
SMITHSONIAN INSTITUTIONU. S. NATIONAL MUSEUM
Vol. 106 Washinglon: 1956 No. 3370A NEW SPECIES OF CANDACIA (COPEPODA: CALANOIDA)FROM THE WESTERN NORTH ATLANTIC OCEAN
T>v Abraham Fleminger and Thomas E. Bowman
The new species of Candacia described below was discovered inde-pendently by the authors while engaged in studies of plankton col-lections made by the U. S. Fish and Wildlife Service (USFWS). Theplankton tows were made off the southern Atlantic coast of theUnited States by tlie Theodore N. Gill and in the Gulf of Mexico bythe Alaska as part of general oceanograpliic surveys of the two regions.In addition to the new species described below, seven known speciesof Candacia have been found in the collections. C. biplnnata Gies-brecht, bispinosa Clans, curta Dana, longimana Claus, pachydactijlaDana, and simplex Giesbrecht occurred in both regions surveyed,whereas a.rmala Boeck has been found only in collections made atsome of the most northern stations occupied by the Gill, off Beaufort,N. C. These stations appear to represent approximately the southernboundary of the distribution of this species along the Atlantic coastof the United States. As pointed out by Thompson and Scott (1903,p. 250), Brady's (1884, p. 68) records from Challenger stations areprobably erroneous. The only other published records from Indo-Pacific or tropical western Atlantic locaUties are contained in C. B.Wilson's Carnegie (1942) and Albatross (1950) reports. Examinationof Carnegie and Albatross specimens in the U. S. National Museum331386590?56
332 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loe(USNM) ideulified by Wilson as C. armata was carried out. Almost allof ^Yilson's determinations proved to be erroneous; C. armata was notpresent at any of the Carnegie stations and onty at Albafrosfi station2195 (lat. :J9?4-i' N., long. 70?03' W., off Cape Hatteras).C. aethiopica Dana, a widespread species in temperate and tropicalwaters of all the oceans, was not found in either the Alaska or Gillcollections. It will probably be found at least in the region coveredby the Gill, since it has been reported from the Bermuda area (Moore,1949), and Mr. Philip St. John (personal communication) has foundit in plankton hauls made otT the coast of North Carolina.Candacia norvegica (Boeck), found in the cooler part of the Noj-thAtlantic Ocean, appears to be limited to waters of lower temperaturethan those surveyed by the Alaska and the Gill. In AVilson's Carnegieand Albatross papers this species was reported to have been found inthe Sargasso and Caribbean regions and in many parts of the PacificOcean. As in the case of C. armata, Wilson's determinations havebeen found to be incorrect. C. norvegica was not present in any ofthe Albatross or Carnegie material in the U. S. National Museum.Candacia paenclongimana, new speciesFigures 1; '2,a-gLocalities and Material: Gulf of Mexico: Lat. 2o?35' N., long.82?23' W. (USFWS Alaska cruise 4, station 29, Jan. 19, 1952, 1 meterdepth of tow, one female); lat. 23?31' N., long. 86?44' AV. {Alaskacruise 4, station 36, Jan. 24, 1952, 1 meter depth of tow, one female).Gulf Stream: Off Florida coast, lat. 27?40' N., long. 79?41' W.(USFWS Theodore N. Gill cruise 1, station G, Feb. 17, 1953, 60 metersdepth of tow, one female); oft' South Carolina coast, lat. 32?41' N.,long. 77?03' W. (Gill cruise 1, station 62, Mar. 3, 1953, 75 metersdepth of tow, one female, one male).Measurements: Ail measurements made from dorsal view alongmidsagittal plane; cephalothorax measured from anteriormost marginof forehead to posterior margin of intersegmental fold between thoracicfusion segment IV-V and genital segment; length of abdomen fromanterior margin of genital segment to articulation between fifthinnermost seta and right fureal ramus. Measurements made at lOOXmagnification with aid of ocular micrometer, specimens immersed insolution of 50 i)ercont glycerine, 50 percent water. Slender glass rodsused to support cephalothorax and abdomen in horizontal positionduring measurements of each.The total length and cephalothorax-abdomen ratio, i)resented inthat order, for individuals collected at diflen^it localities are asfollows: Adult females: holotA'pe, 2.92 mm., 4.1 : 1; paratj^pes, 2.54
NEW SPECIES OF CANDACIA?FLEMINGER AND BOWMAN 333
334 PROCEEDINGS OF THE NATIONAL MUSEUISI vol. loelum., 3.9 : 1 (Alaska station 29); 2.57 mm., 3.7 : 1 {Gill station 62)2.06 nmi. {Gill station 6). Adult male: allotype, 2.49 mm., 3.4 : 1.Diagnosis: Adult female; similar to C. longimana (Claus) withrespect to cophalothorax, cephalic appendages, and swimming legs1-4 (fig. \,ej,h,k-n).Abdominal details differing from longimana: Genital segment withsomewhat angular lateral swellings, greatest width anterior to mid-length of swellings (fig. 1,*^/,^^); measured at greatest width, genitalsegment wider than long (0.82-0.85 : 1); second abdominal segmentproduced ventrad in a broad lobiform process (fig. 1 ,c) ; process extendsventrad and somewhat anteriad, almost reaching posteroventralmargin of genital segment.Fifth legs differing from longimana; spines of ramal segment small;ramus with two apical subcqual spines, two appressed spines alonglateral margin; medial margin of ramus with longitudinal row ofabout five small denticles near apex (fig. l,i,j).Adult male similar to longimana Avith respect to cephalic a])pendagesand swimming legs 1-5.Posterior process of right fifth thoracic segment relatively longerand of rather different form than that of longimana. Seen from above(fig. 2,c) process tapers graduall}^ and turns slightly outward at tip;in lateral view (fig. 2,6) it curves upward to tip, which has an expan-sion on its posterior side.Genital segment (fig. 2,a,d) similar to that of longim,ana, butprocess on right side without thickening near the middle as charac-teristic of longimana.Fifth legs (fig. 2,e) like those of longimana in all details.Types: Holotype, USNM 98618, female, Alaska cruise 4, station 36.AUotype, USNAI 98619, male, Gill cruise 1, station 62. Paratj^pes:USNM 98622, female, Alaska cruise 4, station 29; USNM 98621,female. Gill cruise 1, station 6; USNM 98620, female, Gill cruise 1,station 62.Additional Description: Abdominal segments phis furca withfollowing proportions: Female (based on holotype), 48.5, 25.0, 12.0,14.5=- 100; male, 37.5, 30.0, 27.0, 12.5, 20.0=100.Figure 2.
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a-g, Candacia paenelongimana new species, male allotype: a, dorsal view; b,fifth thoracic segment and first abdominal segment, seen from the right side; c, posteriorcorner of right fifth thoracic segment, dorsal view; d, process of first abdominal segment,dorsal view; e, fifth legs;/, right first antenna, segments 15-19, dorsal view; g, right furcalramus, dorsal view, h-l, Candacia longimana (Claus): h, abdomen, dorsal view, male fromSouth Pacific, USNM 80116; i, portion of fifth thoracic and first abdominal segments,dorsal view, male from same lot as h; j, posterior corner of right fifth thoracic segment,dorsal view, male from Carnegie Sta. 66, off Chile, USNM 80115; k, same, lateral view; /,fifth legs, female, Gill Cruise 1, Sta. 71, off North Carolina; m, abdomen, lateral view, samespecimen. ?, Candacia chirura CIcve, abdomen, lateral view, from Farran (1929).
NEW SPECIES OF CANDACIA?FLEMINGER AND BOWMAN 335
5CALK (MM.)
Figure 2.?Explanation on facing page.
336 PROCEEDINGS OF THE NATIONAL MUSEUM vol. losCephalothorax-abdomen length ratio of female longimana Clans,according to Giesbrecht (1892, p. 428), approximates 2.9 ?.3:1.However, ratios of longimanna collected by GiM and Alaska similarto range in paenelongimana; a female longimana from Gulf of Mexico(unpublished data; lat. 23?50' N., long. 82?19' W., Jan. 19, 1952,1 meter depth) with ratio of 3.8:1; two longimana females from offCape Lookout (unpublished data; lat. 34?03' N., long. 75?15' W.,Mar. 6, 1953, 35 meters depth) with ratios of 3.6:1 and 4.1 :1. Cephal-othorax-abdomen length ratio, therefore, appears to be of no valuein distinguishing between individual females of the two species.Genital segment tends to be longer and furcal rami shorter infemale paenelongimana as compared to available specimens andGiesbrecht's figures (1892, pi. 39, figs. 4, 6) of longimana.Remarks: The female can be easily recognized by the characteristicventral process of the second abdominal segment. While processesfrom the vental surface of this segment are developed to varyingdegrees in several species of Candacia, the process is directed anteriadonly in paenelongimana. Both Candacia chirura Cleve (fig. 2,n) andO. armata (Boeck) have conspicuous processes, directed posteriad.The male can easily be confused with the male of longimana, butcan be distinguished by the shape of the process on the right side ofthe fifth thoracic segment, especially when examined from the side.In longimana this process is somewhat variable, but is relativelyshorter and heavier than in the single male paenelongimana. Indorsal view (fig. 2,h-^) it is more pointed and usually curves medially.Seen laterally (fig. 2,^) it bends abruptly upwai-d just beyond thethickened middle and narrows uniformly to the pointed distal end. Anumber of male specimens of longimana from both the Atlantic andPacific Oceans have been examined; in none of them did this processclosely resemble that of paenelongimana with its uniform curvatureand expanded apex. Literature citedBrady, Geoege Stewardson1884. Report on the Copepoda collected by H. M. H. Challewjer during theyears 1873-76. Rep. Sci. Res. Voyage of H. M. S. Challenger, Zool.,vol. 8, pt. 23, 142 pp., 55 pis.Farran, George P.1929. Crustacea, pt. 10, Copepoda. British Antarctic (Term Nova) Expedi-tion, 1910, Nat. Hist. Rep., Zool., vol. 8, No. 3, pp. 203-306, 37 figs.,4 pis.Giesbrecht, Wilhelm1892. Systematik und Faunistik der pelagischen Copepoden des Golfes vonNeapel und der angrenzenden Meeresabschnitte. Fauna undFlora des Golfes von Neapel, Monogr. 19, 831 pp., 54 pis.
NEW SPECIES OF CANDACIA?FLEMINGER AND BOWMAN 337Moore, Hilary B.1949. The zooplankton of the upper waters of the Bermuda area of theNorth Atlantic. Bull. Bing. Oceanogr. Coll., vol. 12, art. 2, 97 pp.Thompson, Isaac Cooke, and Scott, Andrew1903. Report of Copepoda collected by Professor lierdman at Ceylon in1902. Ceylon Pearl Oyster Fisheries, Suppl. Rep. No. 7; Rep. toColonial Government, pt. 1, pp. 227-307, pis. 1-20,Wilson, Charles Branch1942. The copepods of the plankton gathered during the last cruise of theCarnegie. Carnegie Inst. Washington Publ. 536, Sci. Res. Cruise 7of the Carnegie during 1928-1929 under the command of Cai:)t. J.P. Ault. Biology-I, v + 237 pp., 16 charts, 136 figs.1950. Copepods gathered by the United States Fisheries Steamer Albatrossfrom 1887 to 1909, chiefly in the Pacific Ocean. U. S. Nat. Mus.Bull. 100, vol. 14, pt. 4, pp. i-ix, 141-441, pis. 2-36.
U. S. GOVERNMENT PRINTING OFFICE; 1956