Lysianopsis hummelincki

Lysianopsis hummelincki (Stephensen, 1933) Figs 4, 10 D Lysianassa hummelincki Stephensen, 1933 b: 438–440, fig. 1; Pirlot 1936: 256; Stephensen 1948: 1, 3, table 1; J. L. Barnard 1958: 94; Hurley 1963: 72; Ortiz 1979: 19. Lysianassa falcata Stephensen, 1933 b: 440–441, fig. 2; Stephensen 1948: 1, 4, table 1; J. L. Barnard 1958: 94; Ortiz 1979: 19. Lysianopsis alba Barnard & Karaman, 1991: 499 (in part). Falcanassa falcata Barnard & Karaman, 1991: 486. Lysianopsis hummelincki Lowry & Stoddart, 1997: 82–89, figs 37–39. Material examined. Panama • 4 mm • 1 ♂; Bocas del Toro, Hospital Point; 9.3320°N, 82.2148°W; depth 1–3 m, among coral rubble; 22 June 2023; K. N. White leg.; USNM 1739777. Diagnosis. Upper lip produced well beyond epistome; epistome straight. Gnathopod 1 of male prehensile. Pereopod 7 basis slightly expanded, posterior margin almost straight, merus slightly expanded, approximately 1.4 × width of carpus. Uropod 3 peduncle length about 1.5 × width; outer ramus 1 - articulate. Telson distal margin rounded. Distribution. Lesser Antilles: Curaçao (Stephensen 1933 b); Panama: Bocas del Toro (present study). Ecology and remarks. These amphipods are associated with sand and coral rubble at depths of intertidal 0– 12 m. Panamanian specimens agree closely with previous descriptions with the exception of the almost straight posterior margin on the pereopod 7 basis, which was described by Lowry and Stoddart (1997) as slightly concave. This species is easily recognizable by the 1 - articulate outer ramus on uropod 3 and the prehensile gnathopod 1 in males. Panamanian specimens are white with brown spots when alive.