Melitoides Gurjanova, 1934

Labay, Vjacheslav S., 2014, Review of amphipods of the Melita group (Amphipoda: Melitidae) from the coastal waters of Sakhalin Island (Far East of Russia). II. Genera Quasimelita Jarrett & Bousfield, 1996 and Melitoides Gurjanova, 1934, Zootaxa 3869 (3), pp. 237-280 : 269-270

Genus Melitoides Gurjanova, 1934

Melitoides Gurjanova, 1934: 127 .— Gurjanova, 1951: 752.— Barnard, 1969: 245.— Barnard & Barnard, 1983: 671.—Jarrett & Bousfield, 1996: 33.

Type species. Melitoides makarovi Gurjanova, 1934: 127 .

Species. Including the new species described here, Melitoides contains three species ( Jarret & Bousfield 1996, new data): M. makarovi Gurjanova, 1934 , M. (?) valida ( Shoemaker, 1955) and M. kawaii sp. nov.

Diagnosis (from Jarret & Bousfield 1996 with addition). Pereon segments without dorsal teeth and denticles. Pleon segment 1 smooth; pleon 2–3 or only pleon 3 with mid-dorsal tooth or with few small dorsal teeth. Urosome segments 1 & 2 mid-dorsally toothed. Head with single inferior antennal notch. Antennae regular.

Mouthparts regular. Upper lip shallow notched. Lower lip regular, inner lobes large. Mandible, spine row with few blades; left lacinia 4-dentate, right lacinia 5-dentate; palp segment 3 longer or shorter than 2; segment 1 short, lacking distinct cusp. Maxilla 1, inner plate tall, with medial and apical setae; outer plate with 9 apical tooth setae (Watling type III.1) ( Watling 1989); palp segment 1 usually with shoulder setae; segment 2 slightly extended. Maxilla 2, inner plate with closely submarginal setae. Maxilliped, outer plate medium large; palp segment 2 columnar; dactylus medium.

Coxal plates 1–4 broad, deep. Coxa 1 distally expanded; coxa 4 weakly excavate behind. Pereopod 1 small; merus with a cushion of short setae along distal part of posterior margin; carpus elongate; propodus relatively narrow, shorter than carpus. Pereopod 2 (male), carpus short, hind lobe narrow, deep; propodus large, subrectangular, without dense setation along anterior and posteror margins, palm strongly toothed, with distinct hinge tooth; dactylus regular, outer margin rarely setose.

Coxa 6, anterior lobe not modified in female. Pereopod 4 shorter than 3. Pereopods 5–7 elongated from 5 to 7, basis of pereopods 5 & 6 very large, broad, weakly lobate, base of pereopod 7 large, broad or narrow; segments 4–6 slender, attenuated; dactylus medium long.

Pleon plates 1–3, hind corners weakly or not acuminated. Uropods 1 & 2 regular, rami linear. Uropod 3, inner ramus scale-like, outer ramus short, second segment of outer ramus absent or vestigial. Telson lobes fused basally, apices sub-truncate, with single strong seta.

Coxal gills 2–4 medium, 5 and 6 indistinctly smaller. Brood plates undescribed.

Distribution. Marine waters of boreal Pacific and Arctic shore.

Remarks. According to Jarrett & Bousfield (1996), this genus is a marginal member of the Abludomelita group of genera, differing in a number of character states, including the total reduction of the terminal segment of uropod 3, and the basally fused lobes of telson. The description of new species M. kawaii (see below) and the incomplete description of M. (?) valida (Schoemaker, 1955: description of the uropod 3 is missing, indistinct picture) do not allow to consider the total reduction of terminal segment of outer ramus of uropod 3 as a valid sign.

Jarrett & Bousfield (1996) tentatively attributed M. valida (Schoemaker, 1955) to the genus Melithoides. Signs which pulls together M. valida to the genus Quasimelita : specifics of the dorsal armament, the shape of the pleon plate 3 with produced hind corner, the shape of telson with subapically notched lobes. M. valida close to the genus Melitoides on the armament of pereopod 2, on the shape of coxa 1–4, on the morphology of uropod 3.