Paraflagitopisa

Ariyama, Hiroyuki, 2015, Three new species of the Eriopisa group (Crustacea: Amphipoda: Eriopisidae) from Japan, with the description of a new genus, Zootaxa 3949 (1), pp. 91-110 : 92

Genus Paraflagitopisa , new

Type species. Paraflagitopisa excavata sp. nov. by monotypy.

Diagnosis. Body depressed laterally, smooth; urosomites free. Head longer than pereonite 1, rostrum obsolescent, eyes absent; lateral cephalic lobe rounded without incision, anteroventral sinus indistinct. Antenna 1 long; peduncular articles 1–2 nearly subequal long, article 3 short; accessory flagellum short, 2-articulated; primary flagellum with many articles. Antenna 2 short, slender; flagellum not fused, slightly longer than last peduncular article. Upper lip entire. Mandible with toothed incisor, lacinia mobilis, accessory blades and strong molar; palp with 3 articles, article 1 short, article 2 longer than article 3. Lower lip with small inner lobes. Maxilla 1, inner plate triangular, with many distolateral setae; outer plate with 9 robust setae apically; palp 2-articulated, with distal robust setae. Maxilla 2, inner plate with dorsal oblique row of setae, terminal ends of both plates setose. Maxilliped, inner plate truncate, with a few robust setae distally; outer plate bearing row of robust setae distomedially; palp 4-articulated, article 4 with short nail. Coxae short, weakly overlapping; coxae 1–2 slightly produced forward, coxae 5–6 lobed, coxa 7 smallest; gills large, present on coxae 2–6. Gnathopod 1 in both sexes similar, small, subchelate; carpus longer than propodus, palm transverse. Gnathopod 2 in both sexes large, subchelate; propodus dilated, palm oblique; female gnathopod 2 smaller than that of male. Pereopods 3–4 similar, slender; bases linear. Pereopods 5–7, bases similarly dilated, meri not expanded. Oostegites of female present on coxae 2–5. Pleonal epimera 1–3, posteroventral corners quadrate, ventral margins scarcely setose; first pleonal segment without gills. Pleopods 1–3, peduncles long, each with 2 coupling hooks; inner rami longer than outer. Uropods 1–2 biramous, peduncles each with dorsal and distal robust setae, peduncle of uropod 1 with ventrofacial robust setae; both rami bearing marginal and distal robust setae. Uropod 3 very long, biramous; inner ramus short, slender; outer ramus long, slender, 2-articulated, length of article 2 subequal to article 1. Telson deeply incised, with lateral and distal robust setae.

Etymology. From the Latin para (= beside) and flagitopisa (closely related genus).

Remarks. Paraflagitopisa gen. nov. is characterized by (1) entire lateral cephalic lobe, (2) unfused flagellum of antenna 2, (3) 3-articulated mandibular palp, (4) carpus of gnathopod 1 longer than propodus, (5) transverse palm of gnathopod 1, and (6) slender outer ramus of uropod 3 with long second article. This new genus share these characters with Flagitopisa ; however, Flagitopisa can be distinguished by the following characters ( Paraflagitopisa in parentheses): (1) marked anteroventral sinus of head (indistinct), (2) article 2 of mandibular palp nearly as long as article 3 (longer than article 3), (3) dilated bases of pereopods 3–4 (undilated), (4) first pleonal segment with pair of gills (without gills), and (5) scale-like inner ramus of uropod 3 (slender) [see G.S. Karaman (1984) and Sawicki et al. (2005)]. In addition, Flagitopisa is a freshwater genus.