Quadrimaera quadrimana (Dana, 1852)

Figs 14, 28G

Gammarus quadrimanus Dana, 1852: 955-956, pl. 65, fig. 9.

Maera quadrimana: Schellenberg 1938: 45-48, figs 21, 22; LeCroy 2000: 101, fig. 147; Ruffo et al. 2000: 6-11, figs 1, 2.

Material examined.

Panama • 2-3.5 mm • 7 ♂, 2 ♀, 10 juvenile; Bocas del Toro, Drago; 9.418056°N, 82.3375°W; depth 2-4 m, among coral rubble; 9 Aug 2021; K.N. White leg.; USNM 1703526 • 1 juvenile; Bocas del Toro, Swan Cay; 9.4536°N, 82.300033°W; depth 1-4 m, among coral rubble; 24 Jun 2023; K.N. White leg.; USNM 1703527 • 1 ♀; Bocas del Toro, Crawl Cay; 9.245967°N, 82.136867°W; depth 1-4 m, among Halimeda; 25 June 2023; K.N. White leg.; USNM 1703528 .

Diagnosis.

Antenna 1 accessory flagellum 6-articulate. Gnathopod 1 coxa anteroventrally rounded; carpus with distinct dorsal depression and two short and three long facial setal rows. Gnathopod 2 propodus palmar margin with three U-shaped excavations, increasing in size distally, two small subtriangular projections, and one large truncate projection, palm defined by large projection; dactylus smooth, not expanded. Telson lobes apically truncate, inner margins acute, each with four or five medium-to-long apical spines.

Distribution.

Fiji Islands (Dana 1853); Red Sea (Ruffo 1969); Madagascar (Ledoyer 1972, 1982); Great

Barrier Reef, Australia (Berents 1983); Gilbert Islands (Schellenberg 1938); Micronesia (J.L. Barnard 1965); Hawaiian Islands (J.L. Barnard 1970, 1971); Bermuda: St. George’s Parish, Devonshire Parish (Ruffo et al. 2000); U.S.A.: Florida (Nelson 1995; Thomas 1993; LeCroy 2000); Mexico: Yucatán (McKinney 1977); Brazil (Wakabara et al. 1991; Wakabara and Serejo 1998); Panama: Bocas del Toro (present study).

Ecology and remarks.

These amphipods are associated with algae and coral rubble at depths of 0-10 m. Panamanian specimens closely resemble the description of specimens from Bermuda, with the gnathopod 2 propodus palmar margin showing a slightly more truncate projection than illustrated by Ruffo et al. (2000).