Ringeye Pygmygoby

Trimma benjamini is a species of goby native to the western Pacific Ocean.

Description

It has a reddish-orange body with a narrow pale blue to whitish line around the eye, and a red iris with a whitish to yellow inner ring. A thin vertical bluish grey bar from the anteroventral margin of the eye to the middle of the jaws and a second bar extending more-or-less vertically downward onto cheek from about the middle of the eye (often persisting in preserved material as faint grey bars). Distinguished by having the following characters: a deep concave, ‘U’-shaped interorbital trench; the bony interorbital about half pupil-diameter in width; with a slight groove posterodorsal to the eye; without median predorsal scales, sides of nape covered with small scales reaching to or near to the eyes; cheek and operculum without scales; base of pectoral-fin with oval, moderate-sized scales; prepelvic area with 5-6 rows of cycloid scales, isthmus naked anteriorly, with one slightly enlarged scale on the membrane between the bases of the pelvic fins; central 6-13 pectoral rays branched, uppermost and lowermost rays unbranched; fifth pelvic-fin ray branched once dichotomously and about 60-75% length of the fourth; all other rays usually with one sequential branch, basal membrane connecting the two pelvic fins only at the base; second dorsal spine longest, usually filamentous, extending at most to midway along the base of the second dorsal fin in Australian material; D2 usually I,10; A usually I, 9; nape crest fleshy from the first dorsal origin to above the operculum.

Distribution

Western Pacific: Sulawesi to Tonga; north to Marshall Islands; south to New Caledonia and the Great Barrier Reef.

Habitat and biology

It inhabits coastal and outer reef slopes. Benthic, occuring singly or in loose groups, and a plankton-feeder; with prolonged pelagic larval duration of 33.9 days (= 24% of maximum lifespan) and linear post-larval growth; daily mortality rate ranging from 2.9% to 6.3%; sex ratio of 1:1.6 male/females).