Plumithoe lata, Myers, Alan A., 2012

Myers, Alan A., 2012, Amphipoda (Crustacea) from Palau, Micronesia: Families Ampeliscidae, Ampithoidae, Aoridae, Colomastigidae and Cyproideidae, ZooKeys 193, pp. 1-25 : 9-12

Plumithoe lata sp. n. Figures 9-10

Type material.

Holotype male 2.2 mm OUMNH.ZC.2002-24-0088 Pkuklim Reef; clumps on reef rubble, from Halimeda ( Chlorophyta ) washings, 6 m depth; 07°20.542'N, 134°34.023'E; leg. S. De Grave & C. Burras, 29 May 2002. Paratypes. 2 males, 3 females, 1 imm, collecting data as for holotype.

Etymology.

From the Latin ‘lata’ = wide, in reference to the expanded obtuse elongation of the coxa of the male gnathopod 1.

Description.

Based onmale holotype 2.2 mm.

Head. Head lateral lobes rounded, anterodistal margin scarcely excavate; eyes medium size. Antenna 1 a little over half length of body; peduncular articles short; article 3 about half length of article 1; accessory flagellum absent; flagellum more than two times length of peduncle, with 14 articles. Antenna 2 about two thirds length of antenna 1; peduncle short; articles 4 and 5 subequal; articles 3-5 bearing tufts of long setae on the posterior margin; flagellum with 10 articles. Mandible palp articles in the ratios (basi-distal) 2:3:3.

Pereon. Gnathopod 1 coxa anterodistal margin strongly produced, obtuse; basis short, expanded, with large anterodistal flange; propodus longer than carpus, palm evenly rounded; dactylus overlapping palm. Gnathopod 2 coxa unproduced, deeper than broad; basis robust, expanded, with strongly convex posterior margin and concave anterior margin, moderately produced anterodistal flange; carpus very reduced, cup-shaped, with strongly produced lobe between merus and posterior margin of propodus; propodus elongate, subrectangular, with strong, broad-based posterodistal spine, separated from anterior dactylar lobe by deep triangular excavation; dactylus stout, falciform, slightly overlapping posterodistal spine. Pereopods 3-4 basis elongate-ovoid; propodus without robust setae; dactylus about half length of propodus. Pereopods 5-7 with pyrifom basis. Pereopod 7 scarcely longer than pereopod 6.

Pleon. Epimeron 3 evenly rounded with minute notch bearing minute seta. Uropod 1 peduncle longer than rami, with short distoventral spine; outer ramus longer than inner, both rami lacking marginal robust setae. Uropod 2 peduncle and inner ramus subequal in length; inner ramus longer than outer with one marginal robust seta. Uropod 3 peduncle longer than rami; rami subequal, outer ramus with 2 recurved robust setae. Telson with small telsonic cusps.

Female (sexually dimorphic characters). Gnathopod 2 basis elongate weakly expanded, lacking strong anterodistal flange; carpus subtriangular.

Remarks.

Plumithoe lata sp. n.differs from Plumithoe hirsuta Ledoyer, from Mauritius and Plumithoe madagascarienis sp. n. from Madagascar, in the shape of the male gnathopod 1 coxa, which is expanded both anterodistally and anteroproximally in Plumithoe lata sp. n. but only anterodistally in Madagascan material. It also differs from Plumithoe hirsuta Ledoyer in the straight robust spine on the propodus of the male gnathopod 2 (slender and curved in Plumithoe hirsuta ). Plumithoe lata sp. n. also resembles Plumithoe acuticoxa sp. n. from Fiji, but Fijian material differs in having a slender basis (as in Ampithoe pollex var hirsutus from Mauritius) fringed with long setae in the male gnathopod 2 (a unique feature of Fijian material).

Habitat.

Amongst Halimeda .

Distribution.

Known only from the type locality.