Minyocerus angustus ( Dana, 1852 )

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 : 39-42

Minyocerus angustus ( Dana, 1852)

( Fig. 17 )

Porcellana angusta Dana 1852: 423 . Minyocerus angustus .— Stimpson 1858: 229; Haig 1956: 30; Holthuis 1959: 161; Haig 1962: 184; Gore & Shoup 1968: 240,

figs. 1–3; Gore 1974: 705; Werding 1977: 187, fig. 8; Vargas & Cortés 2006: 463; Almeida et al. 2010: 333, fig. 3; Ferreira

& Melo 2016: 179, fig. 1D; Mantelatto & Miranda 2016: 318, pl. 1; Poupin 2018: 147; Mantelatto et al. 2021: 567, fig. 2C. Porcellana rosamondae Boone 1930: 79 , pl. 21.

Material examined. None from Panama.

Comparative material. Minyocerus kirki Glassell, 1938 . Colombia [Pacific]: 5 females, 3 ov. females, cl cw indet. (CRBM-UV-cr:2004-045), Golfo de Tortugas, traditional shrimp trawl, depth 4–6 m, sand-mud, associated with Luidia columbia (Gray) , leg., R. Neira, 25.09.2004 (det. J.F. Lazarus-Agudelo).

Previous records from Panama. Boone (1930, as Porcellana rosamondae Boone, 1930 ); Gore & Shoup 1968; Rodríguez et al. (2005).

Distribution. West Atlantic: Belize, Honduras, Nicaragua, Costa Rica, Panama (Bahía Limón / Panama Canal área, west of Colón), Colombia, Venezuela, Suriname and Brazil from Pará to Santa Catarina (Holthuis 1959; Gore & Shoup 1968; Gore 1974; Rodríguez et al. 2005; Ferreira & Melo 2016; Mantelatto et al. 2021).

Ecology. Intertidal and subtidal, sandy bottoms, typical depth range: 0–27 m, exceptionally down to 59 m; obligate associate of echinoderms living on sand or muddy sand, mainly sea stars of the genera Luidia Forbes , especially Luidia senegalensis (Lamarck) , Tethyaster Sladen and Astropecten Gray , as well as several genera of brittle stars ( Gore & Shoup 1968; Gore 1974; Veloso & Melo 1993; Almeida et al. 2010; Ferreira & Melo 2016).

Remarks. Minyocerus angustus is a very distinctive symbiotic porcelain crab with a wide geographic range in the western Atlantic. However, it seems to be rather uncommon and found mostly subtidally in the Caribbean Sea and both intertdally and subtidally in Brazil ( Mantelatto & Miranda 2016). For instance, the second author (AA) was unable to find it at several surveyed localities on the Caribbean coast of Panama (including Bocas del Toro and Isla Grande), as well as in the French Antilles and Venezuela.

The presence of M. angustus in Panama is presently based on two older records. The first record was a species described as Porcellana rosamondae by Boone (1930) from Bahía Limón and tentatively placed under the synonymy of M. angustus by Haig (1956). The second record corresponds to a single male specimen collected by an otter trawl at a depth of 24 m west of Colón ( Gore & Shoup 1968), confirming Haig’s (1956) proposed synonymy of P. rosamondae with M. angustus .

The colour pattern of the carapace of M. angustus was described as white or pinkish yellow, marbled with orange-brown, with a narrow median stripe extending from the posterior margin of to the point in front of the lateral spine ( Rathbun 1900; Werding 1977). This description corresponds well to the illustrations of the colour pattern of M. angustus from Panama ( Fig. 17 ) and Honduras in Gore & Shoup (1968), as well as to the colour photos of the Brazilian specimens ( Almeida et al. 2010; Mantelatto & Miranda 2016; Mantelatto et al. 2021).

The eastern Pacific sister species of M angustus is M. kirki Glassell, 1938 , previously known from Mexico to Nicaragua ( Haig 1960), with the above material from the Golfo de Tortugas extending its range significantly south to Colombia. The presence of M. kirki in Nicaragua and Colombia means that the species must also be present in Panama, but has yet to be collected in the latter country for confirmation ( Table 2). Both species of Minyocerus seem to be obligate “commensals” of sea stars ( Luidia spp. ) and larger brittle stars ( Haig 1960; Rodríguez et al. 2005; present study).

Genus Neopisosoma Haig, 1960

Figures

FIGURE 17. Minyocerus angustus (Dana, 1852): A, male (cl 5.5 mm) from west of Colón, Panama (UMML 323357), dorsal view showing colour pattern, right P1 detached; B, ovigerous female (cl 5.0 mm), freshly moulted, from the same locality (UMML 323357), dorsal view; both crabs found in association with Luidia senegalensis [adapted from Gore & Shoup (1968), Bulletin of Marine Science].