Laleonectes vocans (A. Milne-Edwards, 1878 )

In, First Published, 2022, Brachyuran crabs (Crustacea, Decapoda) from the remote oceanic Archipelago Trindade and Martin Vaz, South Atlantic Ocean, Zootaxa 5146, pp. 1-129 : 54-55

Laleonectes vocans (A. Milne-Edwards, 1878)

( Fig. 28A–D )

Neptunus vocans A. Milne-Edwards, 1878: 225 .

Trindade specimens. 1 male ( MZUSP 40172 ), Brazil, off Espírito Santo, Trindade Island , Enseada dos Portugueses, SECON, 20°30’20.9”S, 29°18’43.7”W, J.B. Mendonça coll., 29.iv.2014, 0.9 m . 1 male ( MZUSP 40174 ), ibidem, Enseada dos Portugueses , 20°30’17.7”S, 29°18’56.7”W, J.B. Mendonça coll., 18.iv.2014, 10.2 m . 1 male ( MZUSP 40179 ), ibidem, Ponta da Calheta , 20°30’16.59”S, 29°18’30.11”W, J.B. Mendonça coll., 30.i.2019, 15.1 m . 1 male ( MZUSP 39659 ), ibidem, 20°30’18.72”S, 29°18’31.6”W, J.B. Mendonça coll., 25.vii.2018, 15.6 m . 1 juvenile ( MZUSP 41418 ), ibidem, J.B. Mendonça coll., 20.vii.2014, 16.3 m . 1 juvenile ( MZUSP 41469 ), 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 33836 ), ibidem, Ilha da Racha , 20°30’26.5”S, 29°20’48”W, J.B. Mendonça coll., 3.vi.2015, 23 m . 1 juvenile ( MZUSP 39620 ), ibidem, 30.vii.2018, 24.8 m . 1 juvenile female ( MZUSP 40175 ), Enseada dos Portugueses , SECON, 20°30’20.9’S, 29°18’43.7”W, J.B. Mendonça coll., 29.iv.2014, 9.9 m . 1 juvenile female ( MZUSP 40980 ), ibidem, SECOM/ECIT, J.B. Mendonça coll., 14.v.2014, 10 m . 1 female ( MZUSP 40170 ), ibidem, Enseada das Orelhas , 20°29’40.2”S, 29°20’32.9”W, J.B. Mendonça coll. 21.vii.2015, 15 m . 1 female ( MZUSP 40180 ), ibidem, Ponta Norte , 20°29’18.7”S, 29°20’18.3”W, J.B. Mendonça coll., 23.vi.2016, 11.3 m . 1 juvenile male ( MZUSP 40171 ), ibidem, Praia das Cabritas , 20°29’41.38”S, 29°19’39.99”W, J.B. Mendonça coll., 25.vi.2015, 12 m . 1 juvenile ( MZUSP 41463 ), R/V “Marion Dufresne”, TAAF MD55/Brésil Expedition, off Trindade Island , stn 36 DC61, 20°29’S, 29°18’W, 22.v.1987, 63 m .

Size of largest male: cl 7.2 mm, cw 14.9 mm; female: cl 10.2 mm, cw 20 mm.

Comparative material examined. Laleonectes vocans : Cuba: 1 female ( USNM 19867 ), off Havana, R/V “ Albatross ”, stn 2330, 23°10’48”N, 82°19’15”W, 17.i. 1885, 221 m. Central Atlantic : 1 female ( USNM 190729 ) , Ascension Island, Long Beach, R.B. Manning coll., 23.i.1977 . Brazil: Espírito Santo: 1 female, 2 juveniles ( MZUSP 41459 ), Vitória – Trindade Seamount Chain, R /V “Marion Dufresne” , TAAF MD55/ Brésil Expedition, Dogaressa Bank , stn 24 DC42, 20°54.67’S, 34°01.35’W, 17.v.1987, 60 m. 1 male, 1 juvenile female ( MZUSP 41473 ), ibidem, Dogaressa Bank, stn 25 DC43, 20°51’S, 33°45’W, 17.v.1987, 63 m. 1 male, 1 juvenile ( MZUSP 21202 ), ibidem, Montague Bank, stn 14 DC27, 20°25’S, 36°42’W, 14.v.1987, 81 m. 1 male ( MZUSP 41462 ), H/V “ Antares ”, REVIZEE/Central Expedition, Montague Bank, stn 24C, 20°21’03”S, 36°38’14”W, 7.xi.1997, 62 m. 1 juvenile ( MZUSP 21203 ), Vitória–Trindade Seamount Chain, R/V “Marion Dufresne” , TAAF MD55/ Brésil Expedition, Vitória Bank , stn 13 DC26, 20°21’S, 36°59’W, 14.v.1987, calcareous sand with shell and algal fragments, 97.5 m. 1 juvenile female ( MZUSP 41475 ), ibidem, Vitória Bank, stn 9 DC22, 20°32.39’S, 38°10.49’W, 13.v.1987, 52 m. 1 male ( MZUSP 21205 ), ibidem, stn 10 DC24, 20°41’S, 37°49’W, 13.v.1987, 48 m. 1 female, 2 juveniles ( MZUSP 41461 ), ibidem, Davis Bank, stn 23 DC41, 20°38.50’S, 34°42.93’W, 17.v.1987, sand and rocks, 58– 70 m. 1 juvenile ( MZUSP 41465), ibidem, Davis Bank , stn 23 DC40, 20°39’S, 34°41’W, 15.v.1987, sandy shell, 60 m. 1 juvenile ( MZUSP 41467 ), ibidem, Jaseur Bank , stn 21 DC35, 20°42’S, 35°22’W, 16.v.1987, calcareous sand, 82 m. 2 juveniles ( MZUSP 41471 ), ibidem, Jaseur Bank , stn 20 DC34, 20°28’S, 35°54’W, 15.v.1987, 54 m. 1 female ( MZUSP 41474 ) , ibidem, Jaseur Bank , stn 17 DC30, 20°26.72’S, 36°17.30’W, 15.v.1987, calcareous algae and sand, 60 m. 1 male, 1 female ( MZUSP 41468 ) , H/V “Antares”, REVIZEE/ Central Expedition, Besnard Bank , stn D41, 19°41’S, 38°14’W, 29.ii.1996, 69 m. Rio de Janeiro: 1 juvenile female ( MZUSP 41460 ), H/V “Antares”, REVIZEE/Central Expedition, “ Almirante Saldanha ” Bank , stn 7 BT36, 22°31’S, 37°35’W, M. Tavares coll., 8.ii. 1996, 105 m.

Distribution. Amphi-Atlantic. Western Atlantic: Gulf of Mexico, Antilles, Venezuela and Brazil (Espírito Santo and Rio de Janeiro) ( Grajal & Laughlin 1984; Coelho & Ramos-Porto 1992; Melo 1996; Felder et al. 2009; Diez García 2014). Brazilian oceanic islands: Trindade ( Serejo et al. 2006; Tavares et al. 2017); seamounts (this study): Almirante Saldanha, Besnard, Davis, Dogaressa, Jaseur, Montague and Vitória banks. It is also known from the Pleistocene of Coral Rock, Barbados ( Collins & Morris 1976) and upper Pleistocene of Port Morant Formation, Jamaica ( Donovan 2010). Central Atlantic: Ascension Island ( Rathbun 1930; Manning & Chace 1990; De Grave et al. 2017). Eastern Atlantic: Madeira, Canary Islands; Cape Verde, São Tomé and Annobon ( Monod 1956; Manning & Chace 1990; González 2016).

Ecological notes. Laleonectes vocans ( Fig. 28A–D ) has been reported from a variety of bottoms including calcareous sand, coral, coral rubble, calcareous algae and seagrass flats, between 6 and 310 m ( Grajal & Laughlin 1984; Coelho & Ramos-Porto 1992; Melo 1996). It is the most common swimming crab in Trindade where it has been found in calcareous sand with shell and algal fragments; calcareous sand; sand and rocks; calcareous algae and sand bottoms. It is preyed on by the grouper Cephalopholis cruentata (Lacepède) ( Murillo-Pérez et al. 2021) .

Remarks. The species in Laleonectes can be easily recognized by having a stridulating ridge ( Manning & Chace 1990) stretching along the lateral walls of the carapace, across the pterygostomial region into the infraorbital margin ( Fig. 28B ).

Figures

FIGURE 28. A–D, Laleonectes vocans (A. Milne-Edwards, 1878).A, B, Male, cl 11.2 mm, cw 23.6 mm (MZUSP 40174). Note stridulating ridge (arrows) stretching along the lateral walls of the carapace, across the pterygostomial region into the infraorbital margin. C, D, Male, cl 10.2 mm, cw 20 mm (MZUSP 40179). Habitus, dorsal (A, C) and ventral views (B, D). Photographs by A. Pol.