(Figure 14A)
Material examined. M07, Stn. 86, 558m, ♀ 46.9× 37mm (IEO-CD-MZ07/1907); M08, Stn. 45, 658m, ♀ 78× 66.5mm, ♀ 75.2× 61.9mm (IEO-CD-MZ08/1792), ♂ 62.8× 51.4mm (IEO-CD-MZ08/1792-1), 16S (MZ 424967), COI (MZ 434812); M09, Stn. 5, 548m, ♀ 93.1× 78.2mm (IEO-CD-MZ09/1814), COI (MZ 434813); M09, Stn. 44, 639m, ♀ 135.,9× 111.6mm (IEO-CD-MZ09/1858), 16S (MZ 424968), COI (MZ 434814); M09, Stn. 107, 685m, ♀ 47× 33.1mm (IEO-CD-MZ09/1812), 16S (MZ 424969), COI (MZ 434815).
Habitat and distribution. Chaceon macphersoni occurs at depths between 293 and 900m (Emmerson 2016c) and up to 1025m (Groenevel et al. 2013), in the WIO, off Mozambique, southern Madagascar and eastern South Africa, and extends westwards up to Cape Columbine along the Atlantic coast of South Africa (Groenevel et al. 2013; Emmerson 2016c). Catches of C. macphersoni made off eastern South Africa and Mozambique were attributed to Chaceon quinquedens (Smith) (as Geryon quinquedens) up to 1989, when the family Geryonidae was revised, the new genus Chaceon erected, and C. macphersoni was described (Manning & Holthuis 1988, 1989). This species constitutes an important retained by-catch in multispecies crustacean trawl fisheries and deep-water trap fisheries for spiny lobsters off southern Mozambique (Paula & Silva 1985).
Results and remarks. Our specimens agree well with the descriptions and figures of Manning & Holthuis (1989). Seven specimens were collected during the three surveys (M07, M08 and M09) between 548 and 685m depth.
Colouration observed. The carapace was dorsally yellowish, splashed of small white spots around the branchial and protogastric areas, and with white edges. Chelipeds were pinkish, almost white, and the legs have light pink merus and carpus, and maroon propodus and dactylus.
DNA barcodes. The 16S sequences of three specimens represent two haplotypes (differing in two positions). There are not 16S sequences of this species in Genbank, being these the first ones for this species. The closer matches are with Chaceon maritae (LN 809920) obtained by Hernández et al. (2019) and with C. granulatus (FM 208775) deposited in Genbank by Schubart & Reuschel (2009), varying in six and nine mutations, respectively. Respect to COI, the four sequences obtained for C. macphersoni represent four different haplotypes (differing in two-three positions), that fit 99.2–99.68% of similarity with four sequences of C. macphersoni from South Africa available in BOLD as “private”, and therefore with no access to the sequences and no more data available for comparison.
Subfamily OVALIPIINAE Spiridonov, Neretina & Schepetov, 2014
The subfamily Ovalipiinae was described as family Ovalipidae by Spirodonov et al. (2014). However, Spirodonov (2020), in agreement with the suggestion by Evans (2018) based on his molecular phylogenetic reconstruction, accepted the closer relationships of Ovalipes with geryonids and consequently moved this group as a subfamily of the Geryonidae with only one genus. They are pelagic species known as swimming crabs (Kensley 1981).
Subfamily OVALIPIINAE Spiridonov, Neretina & Schepetov, 2014
The subfamily Ovalipiinae was described as family Ovalipidae by Spirodonov et al. (2014). However, Spirodonov (2020), in agreement with the suggestion by Evans (2018) based on his molecular phylogenetic reconstruction, accepted the closer relationships of Ovalipes with geryonids and consequently moved this group as a subfamily of the Geryonidae with only one genus. They are pelagic species known as swimming crabs (Kensley 1981).