Species of the Parasitic Isopod Genera Ceratothoa and Glossobius (Crustacea: Cymothoidae) from the Mouths of Flying Fishes and Halfbeaks (Beloniformes) NIEL L. BRUCE and HOMAS E. B0WMA1 I W9\ SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY ? NUMBER 489 SERIES PUBLICATIONS OF THE SMITHSONIAN INSTITUTION Emphasis upon publication as a means of "diffusing knowledge" was expressed by the first Secretary of the Smithsonian. In his formal plan for the Institution, Joseph Henry outlined a program that included the following statement: "It is proposed to publish a series of reports, giving an account of the new discoveries in science, and of the changes made from year to year in all branches of knowledge." 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The publications are distributed by mailing lists to libraries, universities, and similar institutions throughout the world. Papers or monographs submitted for series publication are received by the Smithsonian Institution Press, subject to its own review for format and style, only through departments of the various Smithsonian museums or bureaux, where the manuscripts are given substantive review. Press requirements for manuscript and art preparation are outlined on the inside back cover. Robert McC. Adams Secretary Smithsonian Institution S M I T H S O N I A N C O N T R I B U T I O N S T O Z O O L O G Y ? N U M B E R 4 8 9 Species of the Parasitic Isopod Genera Ceratothoa and Glossobius (Crustacea: Cymothoidae) from the Mouths of Flying Fishes and Halfbeaks (Beloniformes) Niel L. Bruce and Thomas E. Bowman SMITHSONIAN INSTITUTION PRESS Washington, D.C. 1989 A B S T R A C T Bruce, Niel L., and Thomas E. Bowman. Species of the Parasitic Isopod Genera Ceratothoa and Glossobius (Crustacea: Cymothoidae) from the Mouths of Flying Fishes and Halfbeaks (Beloniformes). Smithsonian Contributions to Zoology, number 489, 28 pages, 17 figures, 1989.?New diagnoses are given for Ceratothoa and Glossobius. Three species of Ceratothoa and four species of Glossobius are reported from the mouths of four species of flying fishes and six species of halfbeaks, as follows: Ceratothoa angulata from the Philippines (no host) and Borneo (on Hyporhamphus dussumieri (Valenciennes, 1846)); C. guttata from the Philippines (on "flying fish"), the Gulf of Carpentaria, Australia, Taiwan, and Madagascar (on Parexocoetus brachypterus (Richardson, 1846)); C. retusa from Mozambique (no host), Gulf of Carpentaria, Australia (on Hemiramphus robustus Giinther, 1866), Cobourg Peninsula, Northern Territory, Australia (on Hemiramphus far (Forsskal, 1775)), West Irian (on H. far), and Durban, South Africa (on H. far); Glossobius anctus, new species, from Western Australia, New South Wales, Hawaii, and Japan (on Euleptorhamphus viridis (van Hasselt, 1823)); G. auritus from the Bahamas and the Caribbean (on Cypselurus comatus (Mitchill, 1815)), tropical eastern Pacific (no host), Japan (on Cypselurus agoo (Temminck and Schlegel, 1854)), "Ost Indien" (no host), and Thailand (on Cypselurus sp.); G. hemiramphi from Georgia, Florida, the Bahamas, the Caribbean, the west coast of Africa from Dakar, Senegal, to Luanda, Angola (all on Hemiramphus brasiliensis (Linnaeus, 1758)), and Bermuda (on Hemiramphus bermudensis Collette, 1962); G. impressa, western Atlantic from New Jersey to Rio de Janeiro, Brazil, but not in the Caribbean, and eastern Atlantic from Dakar, Senegal, to off Angola at 10?48'S (host not identified except 1 record from Hirundichthyes speculiger (Valenciennes, 1846)). All 7 isopod species are described and illustrated in detail, and a key is given to the species of Glossobius. Cteatessa and Rhexanella are reduced to synonyms of Ceratothoa. Ceratothoa hemiramphi and C. venusta are placed in synonymy with C. retusa and C. guttata, respectively. Glossobius albinae is considered a junior synonym of G. auritus. Glossobius hemiramphi has two disjunct populations, a western Atlantic population ranging from Georgia to the Yucatan Peninsula and in the Caribbean; a west African coastal population ranging from Dakar, Senegal, to Luanda, Angola. Western Atlantic specimens are distinctly longer than those from West Africa. OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. SERIES COVER DESIGN: The coral Montastrea cavernosa (Linnaeus). Library of Congress Cataloging in Publication Data Bruce, Niel L. Species of the parasitic Isopod genera Ceratothoa and Glossobius (Crustacea: Cymothoidae) from the mouths of flying fishes and halfbeaks (Beloniformes) / Niel L. Bruce and Thomas E. Bowman, p. cm.?(Smithsonian contributions to zoology ; no. 489) Includes bibliographical references. Supc of Docs, no.: SI 127:489 1. Ceratothoa?-Classification. 2. Glossobius?Classification. 3. Fishes?Parasites. I. Bowman, Thomas E. II. Tide. III. Scries. QL1.S54 no. 489 [QL444.M34] 591 s?dc20 [595.3*72] 89-600236 CIP Contents Page Introduction 1 Abbreviations 1 Acknowledgments 1 Ceratothoa Dana, 1852 1 Ceratothoa angulata (Richardson, 1910), new combination 2 Ceratothoa guttata (Richardson, 1910), new combination 4 Ceratothoa retusa (Schioedte and Meinert, 1883), new combination 8 Glossobius Schioedte and Meinert, 1883 12 Key to the Species of Glossobius 13 Glossobius anctus, new species 13 Glossobius auritus Bovallius, 1885 16 Glossobius hemiramphi Williams and Williams, 1985 19 Glossobius impressus (Say, 1818) 22 Literature Cited 27 in Species of the Parasitic Isopod Genera Ceratothoa and Glossobius (Crustacea: Cymothoidae) from the Mouths of Flying Fishes and Halfbeaks (Beloniformes) Niel L. Bruce and Thomas E. Bowman Introduction Beloniform fishes are infested by cymothoid isopods on the body surface, in the gill chambers, and in the mouth. Only flying fishes have these isopods on the body surface: Nerocila exocoeti Pillai, 1954, on Exocoetus brachypterus, and Nerocila trichiura (Miers, 1877) on Exocoetus evolans.E. volitans, and Cypselurus nigricans (see Trilles, 1975; Kurochkin, 1980; Bruce and Harrison-Nelson, 1988). The gill-infesting isopods, all members of the genus Mothocya, have been treated in detail by Bruce (1986) in a revision of Mothocya that included material from non-Beloniform host families. The mouth- infesting isopods, except for a few specimens of the taxonomi- cally difficult genus Cymothoa not dealt with here, are species of Ceratothoa and Glossobius. Glossobius is fully revised here, and appears to be restricted to hosts in the families Exocoetidae and Hemiramphidae. Members of the genus Ceratothoa infest a much wider range of fish species, and only three of the more than 40 nominal species are recorded herein from hosts in the Exocoetidae and Hemiramphidae. ABBREVIATIONS.?Abbreviations for institutions listed in the "Material" sections are given in the "Acknowledgments" section below, except for the following: AM, Australian Museum, Sydney; ANSP, Academy of Natural Sciences of Philadelphia; CSIRO, Commonwealth Scientific and Industrial Research Organization; FMNH, Field Museum of Natural History, Chicago; MCZ, Museum of Comparative Zoology, Harvard University, Cambridge; USNM, Collections of the former United States National Museum, now in the National Niel L. Bruce, CSIRO, P.O. Box 89, East Melbourne, Victoria, 3002, Australia. Thomas E. Bowman, Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560. Museum of Natural History, Smithsonian Institution, Washing- ton, D.C; UZMC, Universitets Zoologiske Museum, Copen- hagen. In the "Material" sections, isopod specimens separated by commas were collected from the same fish specimen; isopod specimens separated by semicolons were collected from different fish specimens. ACKNOWLEDGMENTS.?This work was supported by a Smithsonian Postdoctoral Fellowship to N.L. Bruce. For the loan of material used in this study we thank Ake Anderson, Naturhistoriska Riksmuseet, Stockholm (RMS), AJ. Bruce, Northern Territory Museum, Darwin (NTM); PJ.F. Davie, Queensland Museum, Brisbane (QM); H.-E. Gruner, Museum fur Naturkunde der Humboldt-Universitat zu Berlin (MHUB); L.B. Holthuis, Rijksmuseum van Natuurlijke Historic Leiden (RNHL); RJ. Lincoln and J. Ellis, British Museum (Natural History), London (BM(NH)); and M.G. van der Merwe, South African Museum, Cape Town (SAM). Our special thanks go to B.B. Collette, Bureau of Commercial Fisheries Systematics Laboratory, Washington, D.C, who collected and donated the bulk of the material that made this study possible. This manuscript benefitted from careful reviews by R.C Brusca and E.H. Williams. Genus Ceratothoa Dana, 1852 Ceratothoa Dana, 1852:303; 1853:747-752.?Schiocdte and Meincrt, 1883:322-323.?Bowman, 1978:217.?Brusca. 1981:177. Codonophilus Haswell, 1881:471; 1882:283.?Hale, 1926:223. Rhexana Schioedte and Meinert, 1883:289. Cteatessa Schioedte and Meinert, 1883:296. Meinertia Stebbing, 1893:354; 1900:642; 1910a:103.?Richardson. 1905:236.?Menzies, 1962:116.?Schultz, 1969:156. Rhexanella Stebbing, 1911:179. SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY Not Ceratothoa.?Richardson, 1905:236.?Schultz, 1969:155.?Kussakin, 1979:287. [= Glossobius Schioedte and Meinert, 1883.] DIAGNOSIS OF FEMALE (provisional).?Body narrow, about 2.5 to 3.5 times longer than wide, frontal margin of cephalon extended ventrally as short, blunt, triangular rostrum, not separating antennules. Pereonite 1 with anterolateral margins encompassing cephalon. Pleonite 1 much narrower than pleonites 2-5. Antennules with basal articles in contact, proximal articles broad and flattened. Pereopod 1 short, pereopods 2 and 3 longer and more slender than 1; pereopods 5-7 basis with prominent posterior expansion. Pleopods decreasing in size posteriorly, rami with pockets or depressions separated by ridge; pleopod 1 not operculate. MALE.?The same as Glossobius male. TYPE SPECIES.?As Bowman (1978) indicated, the type species, not designated by Dana (1852), must be either Cymothoa gaudichaudii Milne-Edwards, 1840 or Cymothoa parallela Otto, 1828, the two species originally assigned to Ceratothoa by Dana. The presumed holotype of C. gaudi- chaudii is damaged, unrecognizable, and held at the Museum National d'Histoire Naturelle, Paris (Trilles, 1973b). We do not know where the type material of C. parallela is held, or indeed if it is extant Consequently we do not designate a type species for Ceratothoa; this action is best deferred until a generic revision is undertaken. REMARKS.?Since the majority of species of Ceratothoa are still poorly known, and since we have not studied a designated type species for the genus, the diagnosis given here is provisional. Ceratothoa and Glossobius are very similar. However, the characters that separate adult females of the two genera are unambiguous, and it seems prudent to maintain their integrity. Examination of type material of Cteatessa retusa, type species of the genus Cteatessa, reveals no characters by which Cteatessa can be distinguished from Ceratothoa. Schioedte and Meinert (1883) proposed a monotypic new genus for C. retusa. A comparison of their diagnoses of Cteatessa and Ceratothoa shows that they distinguished these two genera by the head size (large to moderate in Ceratothoa, small in Cteatessa), the eyes (distinctly developed in Ceratothoa, obscure in Cteatessa), antenna 1 (dilated, rarely compressed in Ceratothoa, com- pressed in Cteatessa), and the dactyls of the pereopods (usually short in Ceratothoa, very long in Cteatessa). These are mainly quantitative rather than qualitative differences, and we do not believe them to be significant at the generic level. Hence, we consider Cteatessa to be a junior synonym of Ceratothoa. Although we have not examined type material of Rhexana verrucosa Schioedte and Meinert (placed in Rhexanella by Stebbing, 1911), Schioedte and Meinert's (1883) diagnosis fails to distinguish their genus from Ceratothoa. We also place Rhexanella in synonymy with Ceratothoa. Within the genus Ceratothoa species can be grouped according to their pereopod morphology. A feature of the genus, generally considered typical, is the prominent expansion of the basis of the posterior pereopods. Most Ceratothoa species, including the two initially placed in the genus by Dana (1852), have this character. But Ceratothoa gilberti (Richard- son, 1904) (see Brusca, 1981) has no trace of this basal expansion, and it is only weakly developed in Ceratothoa steindachneri Koelbel, 1879 (see Trilles, 1973a). Another pereopodal character that is unequally distributed within the genus is the expansion of the ischium of the posterior pereopods. This occurs in Ceratothoa guttata (Richardson, 1910) and C. carinata (Bianconi, 1870) (see Trilles, 1972). Ceratothoa angulata (Richardson, 1910), new combination FIGURES 1,2 Meinertia angulata Richardson, 1910:22, fig. 21. Codonophilus angulatus (Richardson).?Nierstrasz, 1931:132. MATERIAL.?PACIFIC OCEAN: Philippines: Luzon, Port San Pio (= Port San Pio Quinto, 18?54'N, 121?51'E), near mouth of a small stream, 20 ft. seine, ovigerous 9, 21.5 mm (holotype, USNM 41008). Indonesia: Borneo, ex Hyporhamphus dussumieri (Valenciennes) (Division of Fishes, USNM 218692), non-ovigerous 9, 17.5 mm and cT, 7.0 mm (USNM 240023). TYPE.?Holotype, USNM 41008. TYPE LOCALITY.?See "Material." DESCRIPTION OF FEMALE.?Length/width: holotype 2.5, Borneo 3.2. Width, including coxae, greatest at pereonite 5. Cephalon triangular, rounded anteriorly, lateral margins ante- rior to eyes slightly concave in holotype, nearly straight in Borneo 9. Eyes moderate-size, outlines fairly distinct. Pereo- nite 1 shoulders reaching level of anterior margins of eyes, anterior margins round-truncate, lateral margins shallowly sinuate, anterior one-third to one-half raised into ridge; medial to each ridge is a subcircular depression. Pereonites 2-5 subequal, about two-thirds length of pereonite 2, pereonites 6 and 7 progressively shorter; coxae rather narrow, shorter than pereonites, margins not elevated. Length of pleon as percent of total length: holotype 15.0, Borneo 13.4. All pleonites visible and subequal in length; pleonite 5 equal in width to pleotelson anterior margin. Pleotelson length/width: holotype 0.53, Borneo 0.55, widest at base; lateral margins evenly rounded, posterior margin shallowly emarginate. Antennule composed of 7 dorsoventrally flattened articles. Antenna about as long as antennule, more slender, composed of 8 articles. Antennules and antennae extending to middle of eye, posterior to anterior margin of pereonite 1 shoulders. Labrum crescent-shape. Mandible palp articles all distinct. Maxillule with 2 longer and 2 shorter apical spines. Maxilla with partly fused medial and lateral lobes each armed with 6 recurved spines. Maxilliped palp article 3 with 2 recurved apical spines and 2 more slender straight spines on medial margin. NUMBER 489 FIGURE 1.?Ceratolhoa angulata (non-ovigerous 9, 17.5 mm, Borneo): a, dorsal view; b, pereon, lateral view; c, buccal area; d, maxillule apex; e, maxilla;/, maxilliped; g-m, pereopods 1-7; n-q, pleopods 1-4; r, pleopod S, anterior view; s, pleopod S, posterior view. SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY FIGURE 2.?Ceratothoa angulata (a,