Dulichia KrØyer, 1845

Ariyama, Hiroyuki, 2019, Four Species of Dulichiidae (Crustacea: Amphipoda) from Japan, with the Description of a New Genus and Two New Species, Species Diversity 24 (1), pp. 29-48 : 29-31

Genus Dulichia KrØyer, 1845

[Japanese name: Shakutoridoronomi-zoku]

Dulichia KrØyer, 1845: 521 ; Laubitz 1977: 944; Laubitz 1983: 80; Barnard and Karaman 1991: 657; Myers and Lowry 2003: 470.

Type species. Dulichia spinosissima KrØyer, 1845 , by monotypy.

Emended diagnosis. Body subcylindrical, but urosomites depressed dorsoventrally; pereonites 6, 7 fused; urosomites flexed beneath posterior pereonites and pleonites 1–3, urosomite 1 elongate, urosomites 2, 3 coalesced, shorter than urosomite 1. Head triangular, rostrum well developed; eyes large, prominently convex. Antennae elongate, slender; antenna 1 peduncular articles 2, 3 much longer than article 1, accessory flagellum 2- or 3-articulate; antenna 2 shorter than antenna 1, peduncular articles 4, 5 long. Upper lip broad, fleshy, ventral margin indented and setose. Mandible, molar developed; palp with 3 articles, article 2 longest, article 3 rectolinear. Lower lip with well-developed inner lobes, outer lobes each with mandibular lobe, covered with thin setae apically. Maxilla 1, inner plate short, triangular, without setae; outer plate bearing 9 terminal robust setae; palp 2-articulate, with several robust setae at tip. Maxilla 2 inner plate with mediofacial row of setae. Maxilliped inner plate with 3–4 short robust setae; outer plate not reaching apex of palp article 2, with marginal robust setae; palp consisting of 4 articles, article 4 with long stout seta. Coxae small, short, discontiguous; gills present on coxae 2–5; oostegites of female present on coxae 2–4. Gnathopod 1 weakly subchelate, rather simple; carpus longer than propodus, propodus slender. Male gnathopod 2 enlarged, subchelate; carpus much shorter than propodus, propodus dilated, posterior margin usually with proximal and distal projections, palm oblique, dactylus long. Female gnathopod 2 smaller than that of male, subsimilar to gnathopod 1, subchelate; carpus shorter than or subequal to propodus, palm oblique. Pereopods 3, 4 short, subsimilar to each other; basis slender or expanded, glandular. Pereopods 5–7 greatly elongate, similar to each other, progressively longer; basis linear, propodus without palm, dactylus short. Pleopods large, each with developed peduncle. Uropods 1, 2 slender, biramous, uropod 1 longer than uropod 2, peduncles of both uropods shorter than both rami, outer rami shorter than inner rami; uropod 3 absent. Telson entire, ovate, longer than broad.

Included species. Dulichia biarticulata Hirayama and Takeuchi, 1993 ; D. falcata (Bate, 1857) ; D. latimana sp. nov.; D. rhabdoplastis McCloskey, 1970 ; D. spinosissima KrØyer, 1845 ; D. tuberculata Boeck, 1871 ; D. wolffi Laubitz, 1977 .

Remarks. Laubitz (1977) wrote “pereopods 3 and 4 bases not expanded” as the character of this genus; however in the two Dulichia species, D. biarticulata and D. rhabdoplastis (also in D. latimana sp. nov. as stated below), the basis of the male pereopod 4 is more or less expanded ( McCloskey 1970; Hirayama and Takeuchi 1993).