Moloha alcocki ( Stebbing, 1920 )

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 : 13

Moloha alcocki ( Stebbing, 1920)

( Figure 2D )

Material examined. M09, Stn. 84, 254m, 2 ♂ 54.1× 64.3mm; ♂ 54.4× 65mm (IEO-CD-MZ09/1793), 16S ( MZ 424913 ) .

Habitat and distribution. Seven species of Moloha are known in the IWP ( Ng & Kumar 2015), of which only three are recorded in the WIO. Moloha alcocki inhabits the continental shelf off southern African waters from Namibia to Mozambique ( Kensley 1980a, 1981) and Maldives ( Gordon 1950). It has a wide depth range, between 80 and 800m, being reported at 312m in Mozambican waters ( Kensley 1980a, 1981).

Results and remarks. The two female specimens agree well with the description and figures of Guinot & Richer de Forges (1995) and clearly differ from the close species Moloha major (Kubo) , in the following features: non-cylindrical P2-P4, armed on the upper edge of 4-5 large inclined spines, and another strong distal one, and in the branchial areas of the carapace, near of the union with the cardiac areas, bearing numerous small spines.

The two specimens were collected in the same station, at 254m, in 2009. They were large and had barnacle epibionts on their carapace and legs. These specimens are the second record of the species in Mozambique and extend its minimum depth from 312 to 254m in Mozambican waters.

The variation of names (changes and synonyms) has made that even today there is a great confusion on the species nomenclature, being reported differently in some publications and online resources: as Homola (Paromola) alcocki ( Stebbing, 1920) , Homola alcocki ( Stebbing 1920) , Latreillopsis alcocki Stebbing, 1920 , Paromola alcocki ( Stebbing, 1920) , Thelxiope alcocki (Stebbing, 1922) (WORMS 2021) . Also, it appears indistinctly as M. alcocki and Paromola alcocki in GBIF.org (2021, unpublished record), or as Maloha alcocki in Emmerson (2016b).

Colouration observed. The specimens were bright orange, not uniform, but marble-like in appearance, with small lighter and darker orange patches, even red, both on the cephalothorax and on the ambulatory legs. The dactyls from P2 to P4 are darker, turning to reddish brown, without spots. The chelipeds’ fingers were black. After preservation in ethanol, the specimenscarapaces turned to beige colour, the legs and chelipeds to very light brown and only the finger tips remain with their black original colour.

DNA barcodes. Only a 16S sequence (526 bp) was obtained from one of the ovigerous females. This sequence fits 99.43% (3 mutations) with the sequence of Moloha major (Kubo) (as Moloha majora ) ( KT 182069 ), a complete mitochondrial genome by Shi et al. (2016).

Figures

FIGURE2.A,Homolodromiabouvieri,♀ IEO-CD-MZ08/1801;B,Homola orientalis,♂IEO-CD-MZ09/1806;C,Homolochunia valdiviae, ♀ IEO-CD-MZ09/1805; D, Moloha alcocki, ♀ IEO-CD-MZ09/1793;E, Paromolopsis boasi, ♀ IEO-CD-MOZ08/1827; F, Latreilla metanessa, ♀ IEO-CD-MZ09/1810; G, Latreilla valida, ♀ IEO-CD-MZ09/1779. Scale bars: 1cm.