Laticorophium bifurcatum, Myers, Alan A. & Nithyanandan, Manickam, 2016

Myers, Alan A. & Nithyanandan, Manickam, 2016, The Amphipoda of Sea City, Kuwait. — The Senticaudata (Crustacea), Zootaxa 4072 (4), pp. 401-429 : 410

Family Corophiidae Leach, 1814

Laticorophium bifurcatum sp. nov. ( Fig. 7 )

Type material. Male holotype, 2.2 mm ( NHMUK 2015. 3143), samples from rock and associated seaweeds and hydroids on sides of concrete north tidal gate, within Sea City waterways, 17 March 2014, D.K. Raja. Paratypes, 4 males, 15 females ( NHMUK 2015. 3144–3153), same data as holotype.

Other material. 15 males, 61 females ( NHMUK 2015. 3154–3163), from tunicates attached to concrete sides of north tidal gate in phase A3 Sea City, 20 April 2014, D.K. Raja; 48 males, 102 females ( NHMUK 2015. 3164– 3173), from sponges growing on concrete sides of North Tidal Gate, phase A3, Sea City, 8 April 2014, D.K. Raja.

Description. Based on male holotype 2.2 mm.

Head. Head with short triangular rostrum; Eyes subround. Antenna 1 peduncular articles 1 and 2 subequal, article 1 with two robust setae on the posterior proximal margin, the basal one recurved and two robust setae on the inner proximal margin; article 3 short; peduncular articles clothed with long fine setae; flagellum short, with three articles. Antenna 2 grossly enlarged; peduncular article 4 subrectangular with two strong spines on the posterodistal margin, a short inner one and a longer, recurved outer one; article 5 much more slender and about two thirds length of article 1, posterodistal margin with one spine, sub-distal margin with one spine; flagellum composed of two stout, setose articles. Maxilliped palp well developed, palp article 2 extending beyond end of outer plate.

Pereon. Gnathopod 1, dactyl bifid, tip exceeding short, oblique palm. Gnathopod 2, carpus short, deep, posterodistal margin setose; propodus lacking palm; dactylus short, bidentate. Pereopods 3–4 short; basis broad; segment 4 broadened distally, slightly overhanging short article 5. Pereopods 5–6 short, similar in form but bases unequal in size; segment 5 short, with 2 posterolateral clusters of short hook spines. Pereopod 7 not elongate; basis medium broad; dactyl short.

Pleon. Urosome segments 1–3 fused, plate-like. Uropod 1 peduncle broad elongate, rami much shorter than peduncle, inner ramus longer than outer, both rami with robust setae. Uropod 2 peduncle stout, short; outer ramus shorter than peduncle rounded, with robust and fine setae, inner ramus slender, subequal with peduncle with robust setae. Uropod 3 peduncle short with large outer lobe; ramus short subround. Telson small, rounded.

Female up to 3.0 mm (sexually dimorphic characters). Antenna 2 peduncular article 4 much less robust than that of male, inner margin with one basal, one medio-distal and one distal robust seta; article 5 shorter and more slender than article 4, lacking spines or robust setae.

Remarks. Laticorophium bifurcatum sp. nov. is very close to L. baconi Shoemaker, 1934 . It differs in having the male antenna 2 with a strong spine on the posterior margin of article 5. In this respect it superficially resembles Apocorophium acutum ( Chevreux, 1908) but unlike that species (and genus) it has a notched urosome, a bidentate dactylus on gnathopod 2 and a strongly lobate peduncle of uropod 3. It also differs from L. baconi in having two robust setae inserted on a swollen posteroproximal region of article 4 of the male antenna 2 as well as having the posterodistal spine on article 4 of the male antenna 2 divergent as opposed to recurved.

Distribution. Kuwait

Figures

FIGURE 7. Laticorophium bifurcatum sp. nov., male, 2.2 mm, female (head) 2.0 mm, Sea City, Kuwait.