Leongathus Barnard and Drummond

Taylor, Joanne, 2006, A new species of Leongathus from the Tasman Sea collected during the 2003 NORFANZ Expedition (Crustacea: Amphipoda: Phoxocephalidae), Memoirs of Museum Victoria 63 (2), pp. 207-213 : 208

Leongathus Barnard and Drummond

Leongathus Barnard and Drummond, 1978: 532 . – Barnard and

Karaman, 1991: 617.

Type species. Leongathus nootoo Barnard and Drummond, 1978 (by original designation).

Diagnosis. Rostrum unconstricted. Eyes present, weak or absent. Antenna 1 peduncular article 2 of medium length, ventral setae confined proximally. Antenna 2 peduncular article 1 not or scarcely ensiform, article 3 with 2 facial setules, facial robust setae on article 4 in 1 main row, all robust setae thick, article 5 ordinary. Right mandibular incisor with 3 teeth, right lacinia mobilis bifid, flabellate, denticulate, molar partly triturative, with 7+ large teeth; palpar hump medium, apex of palp article 3 oblique. Maxilla 1 inner plate with 4–5 setae, palp 2-articulate. Maxillipeds ordinary, apex of palp article 3 not strongly protuberant, dactyl elongate, apical nail not distinct.

Gnathopods dissimilar, gnathopod 2 strongly enlarged, carpus of gnathopod 1 of ordinary length, free, of gnathopod 2 short, cryptic (posterior margin concealed by the abutment of propodus and merus), palms oblique, gnathopods 1–2 propodus respectively thin and broadened, poorly setiferous anteriorly. Pereopods 3–4 carpus without posteroproximal robust setae, propodus with mostly thin armaments. Pereopod 5 basis of narrow form or broad form (basis equal to or greater than twice width of ischium), but tapering distally, pereopods 5–6 merus-carpus medium to narrow; pereopod 7 unreduced, article 3 not enlarged, dactyl well developed.

Epimera 1–2 with or without long facial brushes of setae, with or without posterior setae, epimeron 3 bearing long setae. Urosomite 3 without dorsal hook. Uropod 1 peduncle without inter-ramal robust setae, without major displaced robust seta (seta that is shifted onto the apical margin disjunctly from the true inner margin), uropods 1–2 rami not continuously setose to apex, without subapical robust setae or nails, uropod 1 inner ramus with 1 row of marginal robust setae. Uropod 2 inner ramus ordinary. Uropod 3 ordinary, outer ramus longer than peduncle, bearing a 2nd article on outer ramus (minute in L. alannah ), with 2 long apical setae. Telson ordinary.

Remarks. To accommodate the new species the diagnosis of Barnard and Karaman (1991) has been expanded to include the traits eyes present; antenna 2 peduncular article 1 not ensiform; right lacinia mobilis flabellate, denticulate; maxilla 1 inner plate with 4–5 setae; pereopod 5 basis of narrow form or broad form; pereopods 5–6 merus-carpus medium to narrow; epimera 1–2 with or without long facial brushes of setae, with or without posterior setae.