Megalobrachium mortenseni Haig, 1962

Ferreira, Luciane Augusto De Azevedo & Anker, Arthur, 2021, An annotated and illustrated checklist of the porcelain crabs of Panama (Decapoda: Anomura), Zootaxa 5045 (1), pp. 1-154 : 26-28

Megalobrachium mortenseni Haig, 1962

( Fig. 8 )

Megalobrachium mortenseni Haig 1962: 189 , figs. 2–5; Werding 1977: 181, fig. 4; Gore 1982: 6; Rodríguez et al. 2005: 549, pl. 1, fig. A; Vargas & Cortés 2006: 463; Poupin & Lemaitre 2014: 7, fig. 2A; Ferreira & Melo 2016: 176 , fig. 1A; Poupin 2018: 146; Hiller & Lessios 2019: 414, fig. 1f; Ferreira 2019: 59; Mantelatto et al. 2021: 565 , fig. 2A.

Material examined. Panama [Caribbean]: 1 ov. female, cl 2.5, cw 2.6 ( MZUSP 33480 ), Bocas del Toro, southern end of Isla Bastimentos, Cayo Coral (Crawl Cay), depth 0.5–2 m, under and within coral rubble, leg. A. Anker et al., 28.04.2015; 1 male, cl 4.0, cw 4.0, 1 ov. female, cl 4.3, cw 4.5 ( MZUSP 33481 ), same collection data as for previous specimen; 1 male, cl 4.8, cw 4.7 ( FLMNH UF 57119 ), Bocas del Toro , Isla Bastimentos , 9°20’37.9”N, 82°12’24.3” W, depth less than 2 m, in dead coral, leg. P.P.G. Pachelle, 29.03.2019 (fcn PP 19-117) .

Previous records from Panama. Gore (1982); Rodríguez et al. (2005).

Distribution. West Atlantic: Honduras, Costa Rica, Panama (Bocas del Toro, Bahía Limón / Panama Canal area), Colombia, Venezuela, Puerto Rico, N and E Lesser Antilles, Venezuela and Brazil from Pará to São Paulo ( Rodríguez et al. 2005; Poupin & Lemaitre 2014; Ferreira & Melo 2016; Ferreira 2019; Mantelatto et al. 2021; present study).

Ecology. Rocky intertidal and subtidal, in the Caribbean Sea more common in the shallow subtidal, presently known depth range: 0–30 m; under rocks and coral rubble or in crevices of dead corals ( Ferreira & Melo 2016; present study).

Remarks. According to Werding (1977), the colour of the carapace in M. mortenseni varies from nearly white or creamy to pale brown, as in some specimens from Bocas del Toro ( Fig. 8 ) or Brazil ( Mantelatto et al. 2021). Although not very often collected, the species has one of the widest geographic ranges among the western Atlantic porcellanids. Its closest relative seems to be the eastern Pacific M. lemaitrei (Hiller & Lessios 2019) and possibly M. erosum .

Figures

FIGURE 8. Megalobrachium mortenseni Haig, 1962: A, B, male (cl 4.0 mm, cw 4.0 mm) from Bocas del Toro, Panama (MZUSP 33481), dorsal (A) and ventral (B) views [photographs by AA].