Platepistoma guezei ( Crosnier, 1976 )

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 : 22-23

Platepistoma guezei ( Crosnier, 1976)

( Figure 8A )

Material examined. M07,St. 18,530m, ♀ 67.7× 52.6mm (IEO-CD-MOZ07/279);M08,Stn. 4,643m, ♀ 57.2× 43.6mm (IEO-CD-MZ08/1852-1), ♂ 71.7× 43.6mm (IEO-CD-MZ08/1852-2), 16S ( MZ 424930 ) , COI ( MZ 434775 ) ; M09, Stn. 9, 540m, ♀ ov 45.2× 33.9mm (IEO-CD-MZ09/1765), 16S ( MZ 424931 ) , COI ( MZ 434776 ) ; M09, Stn. 27, 543m, ♀ 61.8× 46.2mm, ♂ 63.9× 46.8mm, ♂ 68.3× 52.2mm (IEO-CD-MZ09/1853), COI ( MZ 434777 ) ; M09, Stn. 56, 511m, ♂ juvenile, 12× 9.4mm (IEO-CD-MZ09/1761).

Habitat and distribution. Known only from Reunion Island and Madagascar in the southwestern Indian Ocean. The reported bathymetric range is 350-720m ( Davie 1991).

Results and remarks. The keys from Crosnier (1976), Davie (1991) and Davie & Ng (2012) were used to identify the seven specimens collected at depths between 511–643m in the three surveys. In all specimens, a combination of the features described by Crosnier (1976) for P. guezei and by Davie & Ng (2012) for P. seani were observed. Davie & Ng (2012) differentiated both species based in several characters like: setal coverage from dorsal carapace, carpus and chela; definition of carapace regions; spines of the carapace margins; number of horizontal rows of spines in claws; spines on the carpus of the claw or shape of the male telson. However, none of the seven specimens clearly matches with the complete description of any of both species, and finally we have opted for P. guezei considering that P. seani was described on the basis of one single individual, therefore not covering all the expected variability of the species as well as the features of the male.

Colouration observed. Specimens were covered by a dense brownish tomentum overall and have pink pereiopods with white dactyls and their tips black. The fingers of the chelae were black.

DNA barcodes. Since there are not sequences available for this genus on any public database, the two equal 16S sequences of the specimens from MZ08 and MZ09 as well as the three COI sequences (three haplotypes), are the first DNA markers for this species as well as for the genus.

Figures

FIGURE 8. A, Platepistoma guezei, ♀ IEO-CD-MOZ07/279; B, Dairoides margaritatus, ♀ IEO-CD-MZ07/1911 (preserved); C, Carcinoplax ischurodous, ♂ IEO-CD-MZ08/1824; D, Carcinoplax longimanus, ♂ IEO-CD-MZ08/1787; E, Carcinoplax longimanus, ♀ IEO-CD-MZ08/1851; F, Tanaoa pustulosus, ♀ IEO-CD-MZ08/1776; G, Euclosiana exquisita, ♀ IEO-CD- MZ08/1757. Scale bars: 1cm.