Laleonectes vocans

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).