Membras pygmaea

description

Description. Morphometric data given in Table 1. A dwarf species, less than 41 mm SL. Individuals ≥ 30 mm SL with large testes or large, apparently ripe eggs. Body elongate in appearance; body tapering posteriorly to slender caudal peduncle. Dorsal fins well separated; spinous dorsal posterior to anus and anterior to origin of anal fin. Head length 1 / 2 length of fin. Modified scales with posterior projections at base of spinous dorsal and along second dorsal fin. First dorsal fin spines 3 (1), 4 (10), 5 * (18), 6 (1). Second dorsal fin rays I, 8 (4), I, 9 * (19), I, 10 (7). Anal fin rays: total I, 14 (1), I, 15 (10), I, 16 * (16), I, 17 (3); anterior to second dorsal fin 9 (1), 10 (23), 11 * (6). Pectoral fin rays 12 (1), 13 (20), 14 * (7), 15 (2). Scales: lateral 41 (2), 42 (14), 43 * (8), 44 (5), 45 (1); predorsal 19 (1), 20 (14), 21 * (12), 22 (3); transverse rows 6 * (30); rows around body 14 (1), 16 * (29); rows around caudal peduncle 12 * (30). Gill rakers: total 16 (1), 17 (3), 18 (12), 19 * (11), 20 (3); upper 3 (3), 4 * (25), 2 (2); lower 13 (2), 14 (14), 15 * (13), 16 (1). Vertebrae: total 39 (2), 40 * (17), 41 (8), 42 (1); precaudal 15 * (24), 16 (4); caudal 24 (2),

Two new miniature silverside fishes of the genus Membras Bonaparte (Atheriniformes, Atherinopsidae) from the Tropical North Atlantic Ocean

diagnosis

Diagnosis. A species of Membras belonging to the M. martinica species-group, and differentiable from all congeners by the following characters: anus positioned closer to the insertion of pelvic fin than the origin of anal fin and; posterior margins of predorsal and lateral scales smooth or slightly irregular, not laciniate; least depth of caudal peduncle 6.7 – 8.5 % SL; total gill rakers, first arch 16 – 20, modally 18 or 19.

Two new miniature silverside fishes of the genus Membras Bonaparte (Atheriniformes, Atherinopsidae) from the Tropical North Atlantic Ocean

distribution

Distribution and Habitat. The species is only known from Brus Lagoon, Depto. Gracias a Dios, Honduras (Fig. 2). The habitat for the collections was a salt marsh with channels bordered by reeds and saw grass. The bottom was peaty. The channel in which the species was collected was on the coastal edge of the lagoon-salt marsh complex.

Two new miniature silverside fishes of the genus Membras Bonaparte (Atheriniformes, Atherinopsidae) from the Tropical North Atlantic Ocean

etymology

Etymology. The species-group name, pygmaea, an adjective derived from the Latin meaning little or dwarf, referring to the diminutive size of the species.

Two new miniature silverside fishes of the genus Membras Bonaparte (Atheriniformes, Atherinopsidae) from the Tropical North Atlantic Ocean