Colomastix lecroyae, 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 : 14-17

Colomastix lecroyae sp. n. Figures 13-14

Type material.

Holotype male 2.5 mm, OUMNH.ZC.2002-24-0093, Outside Pinchers, rubble slope, from Melophlus sarasinorum Thiele, 1899 ( Porifera : Ancorinidae ), 10 m depth; 07°20.407'N, 134°25.755'E; leg. S. De Grave & C. Burras, 26 May 2002.

Etymology.

Named for Sara LeCroy for her extensive and invaluable work on this genus of amphipods.

Description.

Based on male holotype, 2.5 mm.

Head.Head longer than peron segment 1; interantennal plate extending far beyond anterodistal angle, anterior margin straight, with ventral spine. Antenna1 1-2 marginal robust setae stout. Antenna 2 very stout, weakly setiferous.

Pereon.Gnathopod 1 coxa weakly produced; dactylus with two stout distal setae. Gnathopod 2 coxa evenly rounded; basis grossly swollen distally, anterior margin irregularly scalloped; propodus sub-ovoid, posterior margin with medial spine, palm with small rounded lobe fitting concavity on posterior margin of dactylus. Pereopods 3-4 with rounded anterodistal lobe. Pereopods 5-7 basis weakly expanded distally.

Pleon. Uropod 1 rami subequal, about two thirds length of peduncle; inner ramus with modified weakly hooked tip. Uropod 2 rami subequal with each other and with peduncle; inner ramus with weakly curved, acute tip. Uropod 3 rami lanceolate; inner ramus a little shorter than outer ramus and shorter than peduncle. Telson narrowly subtriangular, more than twice as long as broad, distally excavate, and with ventral proximal protrusion.

Female.

Unknown

Habitat.

Among sponges.

Remarks.

In the shape of the male gnathopod 2 this species resembles Colomastix truncatipes Ledoyer from Madagascar, but in that species the basis of that appendage has an evenly rounded anterodistal margin, whereas in Colomastix lecroyae sp. n. the margin is complexly scalloped. Colomastix truncatipes also has very unequal rami on uropod 3, whereas they are almost subequal in Colomastix lecroyae sp. n. The single male Colomastix sp. described by Ledoyer from New Caledonia is 1.9 mm in total length and appears to be immature. It may be synonymous with Colomastix lecroyae sp. n. but has a peculiar character in its bilobed inner lobe of the maxilliped.

Distribution.

Known only from the type locality.