Cochinorchestia tulear, Lowry, J. K. & Springthorpe, R. T., 2015

Lowry, J. K. & Springthorpe, R. T., 2015, Coastal Talitridae (Amphipoda: Talitroidea) from north-western Australia to Darwin with a revision of the genus Cochinorchestia Lowry & Peart, 2010, Zootaxa 3985 (2), pp. 151-202 : 175-177

Cochinorchestia tulear sp. nov.

( Fig. 15 )

Orchestia notabilis .— Ledoyer, 1986: 1010, fig. 399.

Types. Holotype, male, 8 mm, MNHN-IU-2008-23645, Tuléar , Madagascar, station CIR Rhi 4.13.8, coll. Roman.

Type locality. Tuléar , Madagascar.

Etymology. Named for the type locality, Tuléar , Madagascar.

Habitat. Unknown.

Description. Based on holotype, male, 8 mm ( Ledoyer, 1986: 1010, fig. 399).

Head slender scales on ventroproximal surface unknown. Eye large (greater than 1/3 head length). Antenna 1 apparently reaching end of antenna 2 peduncle. Antenna 2 article 5 longer than article 4; flagellum virgula divina unknown. Maxilla 1 with small palp, 2-articulate. Maxilliped palp article 2 distomedial lobe well developed; article 4 small, well defined.

Pereon. Gnathopod 1 subchelate; coxa smaller than coxa 2; posterior margin of merus, carpus and propodus each with lobe covered in palmate setae; carpus 1.5 × as long as propodus, 2 × as long as broad; propodus subtriangular with well developed posterodistal lobe, anterior margin with 2 groups of robust setae, lateral surface with 5 cuspidate setae, with 7 serrate setae, palm nearly transverse, without spine patch on posterodistal corner; dactylus subequal in length to palm. Gnathopod 2 sexually dimorphic; subchelate; basis slightly expanded; ischium with rounded lobe on mid-anterior margin, ischium without anterodistal lobe on medial surface; posterior margin of merus, carpus and propodus each without lobe covered in palmate setae; carpus triangular, reduced (enclosed by merus and propodus), posterior lobe absent, not projecting between merus and propodus; propodus subovate, 1.6 × as long as wide, palm extremely acute, reaching about 58% along posterior margin, strongly toothed, incised or sinuous, with broad distal shelf, large sinus, rounded tooth, large sinus with minute rounded tooth, lined with robust setae (11 lateral), cuticular patch at corner of palm unknown; dactylus subequal in length to palm, curved, without anteroproximal bump, posterior margin smooth, not modified distally, blunt.

Pleon. Epimeron 3 posterior margin smooth, without setae, with small subacute tooth. Uropod 1 peduncle with 6 robust setae, including very large distolateral robust seta (1/3–1/2 length of outer ramus), with simple tip; inner ramus subequal in length to outer ramus, without marginal robust setae; outer ramus with 2 marginal robust setae. Uropod 2 peduncle with 4 robust setae; inner ramus subequal in length to outer ramus, with 2 medial robust setae; outer ramus without marginal robust setae. Uropod 3 peduncle with 2 robust setae; ramus not fused to peduncle; ramus shorter than peduncle, ramus 1.7 × as long as broad, ramus linear, tapering distally, with 2 apical setae. Telson as broad as long, entire, dorsal midline absent, with 2 apical robust setae per lobe.

Female. Unknown.

Remarks. Cochinorchestia tulear belongs to the species group with a strongly toothed palm on male gnathopod 2. It is unique in this group in not having robust setae on the inner ramus of uropod 1.

Distribution. Madagascar. Tuléar , Madagascar ( Ledoyer 1986).

Figures

FIGURE 15. Cochinorchestia tulear sp. nov., male, holotype, 8 mm, MNHN-IU- 2008 - 23645, Tulear, Madagascar. Scale lines represent 0.1 mm (After Ledoyer, 1986: 1010, fig. 399).