Raninoides crosnieri Ribes, 1989

Muñoz, Isabel, García-Isarch, Eva & Cuesta, Jose A., 2021, Annotated and updated checklist of marine crabs (Decapoda: Brachyura) of Mozambique supported by morphological and molecular data from shelf and slope species of the “ MOZAMBIQUE ” surveys, Zootaxa 5056 (1), pp. 1-67 : 18

Raninoides crosnieri Ribes, 1989

( Figure 4B )

Material examined. M07, Stn. 40, 190m, ♂ 16.2× 27.1mm (IEO-CD-MZ07/1910), 16S ( MZ 424922 ) .

Habitat and distribution. The known distribution of Raninoides crosnieri is the type locality, Madagascar, at depths between 160 and 210m ( Ribes 1989).

Results and remarks. Only one specimen was recorded at 190m depth in M07. It is a male mostly agreeing with the description of R. crosnieri given by Ribes (1989), although not completely. There are characteristics that clearly distinguish it from Raninoides personatus Henderson , the other similar species of the Indian Ocean, and agree with the R. crosnieri description, such as: a sub-distal spine in the carpus of the chelipeds (although it is accompanied by a distal one) and the edge of the carpus rough; the upper edge of P4 somewhat concave; on the upper edge of P5 which there are indications that there was a spine in each, which are broken. However, the rostrum of this specimen (see Figure 5A ) differs with that described by Ribes (1989) for R. crosnieri (see Figure 5B ), and rather fits the description of the rostrum of R. personatus “rounded at its end” (see Figure 5C ). Ribes (1989) considered the rostrum shape as one of the main differences separating R. crosnieri from R. personatus , and therefore this new evidence put under question the taxonomic validity of this feature.

This is the first record of R. crosnieri in Mozambique waters, and the second one of this species worldwide.

Colouration observed. The cephalothorax and pleon were orange-brown, with marble-like spots. The legs and chelipeds were light beige, with some not very well-defined faint brown-orange spots.

DNA barcodes. There are not sequences available for this species on any public database. The 526 bp sequence of 16S obtained for the specimen IEO-CD-MZ07/1910 is the first genetic marker for this species.

Section EUBRACHYURA Saint Laurent, 1980

Subsection HETEROTREMATA Guinot, 1977

Superfamily CALAPPOIDEA De Haan, 1833 [in De Haan, 1833 –1850]

Family CALAPPIDAE De Haan, 1833 [in De Haan, 1833 –1850]

According to Davie et al. (2015a), this family includes nine genera and 89 species. Only two of these genera have been recorded in Mozambican waters, Calappa Weber and Mursia Desmarest ( Emmerson 2016b,c; Lai & Ng 2006; Spiridonov & Apel 2007). Calappidae crabs are known as box-crabs and inhabit from shallow to deep waters, usually burying ( Davie et al. 2015a).

Figures

FIGURE 4. A, Lyreidus brevifrons, ♂ IEO-CD-MZ08/1771; B, Raninoides crosnieri, ♂ IEO-CD-MZ07/1910; C, Calappa africana, ♀ IEO-CD-MZ08/1815; D, C. africana, ♂ IEO-CD-MZ08/1797; E, Mursia africana, ♂, IEO-CD-MZ08/1797; F, Mursia aspera, ♂ IEO-CD-MZ07/1903 (preserved); G, Mursia flamma, ♀ IEO-CD-MZ07/1904; H, Mursia sp, ♂ IEO-CD- MZ09/1775. Scale bars: 1cm.

FIGURE 5. Rostrum. A, Raninoides crosnieri ♂ IEO-CD-MZ07/1910; B, Raninoides crosnieri; C, Raninoides personatus. B and C after Ribes (1989). Scale bars: 1cm.