Elasmopus balkomanus Thomas & Barnard, 1988

White, Kristine N. & Sir, Sally J., 2024, Caribbean Amphipoda (Crustacea) of Panama. Part II: parvorder Hadziidira, ZooKeys 1195, pp. 249-296 : 249

Elasmopus balkomanus Thomas & Barnard, 1988

Figs 4 , 27D

Elasmopus balkomanus Thomas & Barnard, 1988: 838-842, figs 1-3; LeCroy 2000: 86, fig. 133.

Material examined.

Panama • 1.6-8 mm • 1 ♀; Bocas del Toro, Crawl Cay ; 9.2475°N, 82.1290°W; depth 5 m, among coral rubble; 12 Aug 2021; K.N. White leg.; USNM 1703499 • 1 ♂; Bocas del Toro, Crawl Cay; 9.245967°N, 82.136867°W; depth 1-4 m, among sand; 25 June 2023; K.N. White leg.; USNM 1703500 .

Diagnosis.

Gnathopod 1 male propodus subovate, palm oblique, female propodus slender, ventral margin straight. Gnathopod 2 male propodus palm densely setose with crenulate longitudinal ridge on medial surface, female propodus with 2 spines at palmar angle. Pereopod 5 basis posterior margin concave. Pereopod 7 basis posterior margin without long setae, articles 4 and 5 of male unexpanded, slender. Epimeron 3 posteroventral margin with small tooth. Telson inner lobes shorter than outer lobes, apically acute.

Distribution.

U.S.A.: South Florida, Looe Key ( Thomas and Barnard 1988; Thomas 1993), Biscayne Bay ( LeCroy 2000); Panama: Bocas del Toro (present study).

Ecology and remarks.

These amphipods are associated with algal turf and coral rubble at depths of 1-5 m. Panamanian specimens have a less setose gnathopod 2 propodus and less concave pereopod 5 basis than described by Thomas and Barnard (1988). The gnathopod 2 propodus is also less inflated than previously described. This suggests variation in these characters with size as the Panamanian specimens were smaller than those described by Thomas and Barnard (1988). Other characters agree with previous descriptions of this species.

Figures

Figure 4. Elasmopus balkomanus, male 1.6 mm, pereopod 5, telson, gnathopod 2 medial, epimeron 3 posterovental corner; female, 3.7 mm, gnathopod 1 lateral. Scale bars: 0.5 mm.

Figure 27. Photographs of live specimens A Dulzura schoenerae B Ceraocus sheardi C Ceradocus shoemakeri D Elasmopus balkomanus E Elasmopus elieri (ethanol preserved specimen) F Elasmopus levis G Elasmopus longipropodus. Scale bars: 1.0 mm.