Glossobius Schioedte & Meinert, 1883

Martin, Melissa B., Bruce, Niel L. & Nowak, Barbara F., 2015, Review of the buccal-attaching fish parasite genus Glossobius Schioedte & Meinert, 1883 (Crustacea: Isopoda: Cymothoidae), Zootaxa 3973 (2), pp. 337-350 : 338-339

Glossobius Schioedte & Meinert, 1883

Glossobius Schioedte & Meinert, 1883: 299 .— Bruce & Bowman, 1989: 12.

Ceratothoa .— Richardson, 1905: 283.— Schultz, 1969: 155.— Kussakin, 1979: 287.

Types species. Ceratothoa linearis Dana, 1853 [junior synonym of Glossobius impressus ( Say, 1818) ]; by subsequent designation ( Bruce & Bowman 1989).

Diagnosis (female). Cephalon not immersed in pereonite 1, anterolateral margin concave. Eyes present. Pereonite 1 anterolateral margins minute or projecting laterally, anterior margin straight or slightly convex. Pleonite 1 overlapped by pereonite 7, narrower than pleonites 2–5.

Antennula bases contiguous, peduncle articles 1–3 of similar size and bigger than other articles, peduncle articles 1–3 anterodistal margins produced, terminal articles without setae. Coxae not overlapping adjacent pereonites. Brood pouch arising from coxae 1–4 and 6. Mandible articles 1–3 articulated. Maxilla with welldefined medial and lateral lobes. Maxilliped palp article 3 apex with multiple recurved spines.

Pereopods 5–7 basis with raised carina. Uropod rami not extending beyond pleotelson posterior margin.

Remarks. Glossobius can be recognized by the cephalon not being immersed in pereonite 1; pereonite 1 with minute anterolateral margins or margins projecting laterally; cephalon anterolateral margins concave; antennule bases contiguous; pleopods with transverse ridges, endopods with weak proximomedial lobes, endopods 2–5 with depressions; and expanded posterior margin of pereopods 4–7 bases. For male diagnosis see Bruce & Bowman (1989).

Other similar buccal-attaching genera differ from Glossobius in the following characteristics: Ceratothoa pereonite 1 anterolateral margins projecting forward; pereonite 6 longer than Glossobius ; anterior margin of pereonite 1 indented ( Bruce & Bowman 1989); Cinusa Schioedte & Meinert, 1884 : pereonite 3–4 widest anteriorly; antennae slender ( Hadfield et al. 2010); brood pouch arising from coxae 2–5 (Hadfield 2012); Lobothorax Bleeker, 1857 : pereonite 1 anterolateral margins rounded, with strongly developed lobes, dorsally concave and flattened, extending past rostrum; pleopod exopods with proximolateral lamella ( Yu & Bruce 2006); brood pouch arising from coxae 2–4 and 6 (Hadfield 2012); Cymothoa Fabricius, 1793 : antennula basally widely separated; cephalon rostrum ventrally folded (Hadfield 2012); pleopods with fleshy and thick folds ( Martin et al. 2013); and Smenispa, 2009 : pleopods 3–5 have large folds, and pereon and pleon are co-linear with subparallel lateral margins ( Martin et al. 2014a).

Species of Glossobius (see Table 1 ) are restricted to beloniform fishes. Glossobius arimae Nunomura, 2001 was the only species associated with a non-beloniform fish and did not morphologically agree with the genus; G. arimae is here transferred to the genus Ceratothoa (see remarks in section Ceratothoa arimae ( Nunomura, 2001) comb. nov.). Glossobius species display different levels of host specificity towards beloniform hosts. Glossobius anctus and G. parexocoetii are known from one host species, G. hemiramphi is known from two host species of the genus Hemiramphus , G. impressus is known from six host species of the family Exocoetidae , and G. auritus is known from five host species from two families. Despite the different levels of host preference for Glossobius , all species appear to be cosmopolitan (see comments on distribution for each species).