Portunus anceps ( Saussure, 1857 )

TAVARES, MARCOS & MENDONÇA, JOEL BRAGA DE JR., 2022, Brachyuran crabs (Crustacea, Decapoda) from the remote oceanic Archipelago Trindade and Martin Vaz, South Atlantic Ocean, Zootaxa 5146 (1), pp. 1-129 : 56

Portunus anceps ( Saussure, 1857)

( Fig. 29A–F )

Lupea anceps Saussure, 1857: 502 [Type locality: Cuba].

Lupea anceps Saussure, 1858: 434 (18) [see Hollier, 2018].

Trindade and Martin Vaz specimens. 1 male ( MZUSP 33826 ), Brazil, off Espírito Santo, Trindade Island, Praia do Lixo , 20°31’29.8’S, 29°19’43.9”W, J.B. Mendonça coll., 25.x.2014, 13.7 m . 1 juvenile ( MZUSP 40185 ), ibidem, J.B. Mendonça coll., 22.xi.2017, 12.7 m . 1 female ( MZUSP 40178 ), ibidem, Ponta Norte , 20°29’18.7”S, 29°20’18.3”W, J.B. Mendonça coll., 27.xi.2017, 10.7 m . 1 male ( MZUSP 40184 ), ibidem, Enseada das Orelhas , 20°29’40.2”S, 29°20’32.9”W, J.B. Mendonça coll., 27.xi.2017, 10.3 m . 2 juveniles ( MZUSP 40181 ), ibidem, Enseada dos Portugueses, R /V “Marion Dufresne”, TAAF MD55/Brésil Expedition coll., 22.v.1987, vacuum suction sampler, 10 m . 3 juveniles ( MZUSP 41464 ), ibidem, off Trindade Island , stn 36 DC61, 20°29’S, 29°18’W, 22.v.1987, 63 m . 1 juvenile ( MZUSP 40183 ), ibidem, Ponta da Calheta , 20°30’18.72S, 29°18’31.6”W, J.B. Mendonça coll., 24.xi.2017, 17 m . 1 juvenile ( MZUSP 41470 ), R/V “Marion Dufresne”, TAAF MD55/Brésil Expedition, Ponta da Calheta , stn 35 DC59, 20°30.37’S, 29°18.55’W, 22.v.1987, 60 m . 1 male ( MZUSP 40176 ), Martin Vaz Archipelago , 20°28’42.74’’S, 28°51’8.98’’W, J.B. Mendonça coll., 25.i.2019, 10.6 m .

Size of largest male: cl 8.9 mm, cw 17 mm; female: cl 10.6 mm, cw 21.9 mm.

Comparative material examined. Portunus anceps : Central Atlantic: 1 male ( USNM 252328 ), Ascension Island, North edge of Southwest Bay , McArthur Point, Turtle Shell Beach, stn ASC-22, R.B. Manning coll., v.1971 . Brazil: Par: 1 female ( USNM 15258 ), off Carutapera, R /V “ Oregon ”, stn 4220, 00°01’N, 45°48’W, dredge, 54.8 m. Ceará: 1 male ( MZUSP 8940 ), R/V “Almirante Saldanha”, stn DG 01, 3°32.5’S, 38°39.5’W, 19.vii.1987 . São Paulo: 1 female ( MZUSP 13086 ), Ubatuba, v.1998 .

Distribution. Bermuda, North Carolina, Gulf of Mexico, Antilles to Brazil (Amapá to Ceará, Pernambuco to Bahia, Rio de Janeiro, São Paulo) ( Melo 1996; Felder et al. 2009; Mantelatto et al. 2020). Brazilian oceanic islands: Fernando de Noronha and Rocas Atoll ( Coelho Filho 2006; Alves et al. 2008; Alves et al. 2017), Trindade ( Serejo et al. 2006) and Martin Vaz (this study). Central Atlantic: Ascension Island ( Manning & Chace 1990).

Ecological notes. Portunus anceps inhabits a variety of bottom types more commonly sand, shell, under rocks in sandy bottoms, rubble, macro- and calcareous algae, and rarely mud, between 1m and 130 m, occasionally 510 m ( Coelho & Ramos 1972; Coelho & Ramos-Porto 1992; Melo 1996; Felder et al. 2009; Alves et al. 2017). Portunus anceps has also been reported from pelagic Sargassum (see Fine 1970). Manning & Chace (1990) found P. anceps in protected tide pool with coarse sand bottom. In Trindade it has been found under rocks in sandy bottoms between 10 and 17 m; the juvenile MZUSP 41470 was dredged at 60 m. The mottled color pattern of the carapace dorsal surface enables the crabs to conceal themselves by matching the colors and patterns of the substrate, whereas the crab’s ventral surface is uniformly whitish ( Fig. 29A–F ).

Remarks. Manning & Chace (1990) reported that the Ascension specimens have larger carapace submedian frontal teeth when compared to specimens from elsewhere. The Trindade specimens differ from the male USNM 252328 from Ascension in that the carapace submedian frontal teeth are only slightly less advanced than the outer teeth (vs comparatively much less advanced in the Ascension specimen). The specimens from Trindade and Ascension otherwise agree well with each other. The shape of the carapace and the development of the submedian frontal teeth (more advanced in the younger stages) actually change considerably with the growth ( Fig. 29A, C–E ).

Figures

FIGURE 29. A–F, Portunus anceps (Saussure, 1857).A, B, Female, cl 10.6 mm, cw 21.9 mm (MZUSP 40178). C, Male, cl 8.9 mm, cw 17 mm (MZUSP 33826). D, Juvenile, cl 2.9 mm, cw 3.9 mm (MZUSP 40185). Note in (C, D) changes with growth in the shape of the carapace and development of the submedian frontal teeth (arrows); the submedian frontal teeth more advanced in the younger stage (D). E, F, Male, cl 6.5 mm, cw 12 mm (MZUSP 40184). Habitus, dorsal (A, C–E) and ventral (B, F). Photographs by A. Pol.