Brachycarpus biunguiculatus ( Lucas, 1846 )

Ashelby, Christopher W., Lin, Wei-Cheng, Grave, Sammy De & Chan, Tin-Yam, 2018, Notes on the shrimp genus Palaemon Weber, 1795 (Crustacea, Decapoda, Palaemonidae) and related genera from Taiwan, Zootaxa 4446 (4), pp. 575-595 : 576-577

Brachycarpus biunguiculatus ( Lucas, 1846)

( Fig. 1 )

Material examined. Magang , New Taipei City, 1 female (pocl 3.9 mm), 04.IX.1994 ( NTOU M01215 ).

Diagnosis. Rostrum nearly straight dorsally; dorsal spines of telson not submarginal, directed posteriorly; anterolateral tooth of basal segment of antennular peduncle overreaching second segment; mandibular palp not reduced, reaching at least to distal third of incisor process; carpus of first pereiopod slightly longer than chela.

Colour pattern. Not recorded for the Taiwanese specimen.

Remarks. Although small and missing several pereiopods, the specimen examined here undoubtedly belongs to B. biunguiculatus based on the proportion of the carpus of the second pereiopod, the biunguiculate dactyli of the ambulatory pereiopods and possession of a hepatic rather than branchiostegal spine.

Ecology. Littoral and sublittoral to around 100 m. In reefs and coral rubble, weed covered rocks and rock crevices, occasionally in seagrass. Primarily nocturnal, usually concealed during daylight.

Distribution. Presumed to be pan-tropical/subtropical, now recorded from Taiwan for the first time.

Figures

FIGURE 1. Brachycarpus biunguiculatus (Lucas, 1846). Female (pocl. 3.9 mm, NTOU M01215). A) carapace, right lateral view; B) left fifth pereiopod, lateral view; C) same, dactylus, mesial view; D) left second pereiopod, lateral view. Scale bars indicate 1.0 mm.