Paractaea nodosa (Stimpson, 1860)

(Fig. 40A–J)

Actaea nodosa Stimpson, 1860: 203 [Type locality: Tortugas, Florida]

Trindade and Martin Vaz specimens. 1 juvenile female (MZUSP 41276), Brazil, off Espírito Santo, Trindade Island, Enseada das Orelhas, 20º29’40.2”S, 29º20’32.9”W, J.B. Mendonça coll., 1.xi.2014, 12 m. 1 male (MZUSP 33733), ibidem, J.B. Mendonça coll., 9.v.2014, 14.8 m. 1 juvenile female (MZUSP 41278), ibidem, J.B. Mendonça coll., 5.v.2014, 14.7 m. 1 juvenile female (MZUSP 40960), ibidem, Enseada dos Portugueses, Farol, 20º29’52.3”S, 29º19’15.6”W, J.B. Mendonça coll., 22.iv.2014, 13.7 m. 1 ovigerous female (MZUSP 40930), ibidem, J.B. Mendonça coll., 4.xii.2017, 12.7 m. 1 juvenile male (MZUSP 39584), ibidem, Ponta da Cachoeira, 20º30’31.18”S, 29º20’39.59”W, J.B. Mendonça coll., 21.vii.2015, 19 m. 1 juvenile male (MZUSP 41279), ibidem, Praia da Calheta, 20º30’29.5”S, 29º18’37.0”W, J.B. Mendonça coll., 21.vi.2016, 12.5m. 1 female (MZUSP 40951), ibidem, Enseada da Cachoeira, Farrilhões, 20º31’29.8’’S, 29º19’52.0’’W, J.B. Mendonça coll., 7.viii.2018, 10.3 m. 1 juvenile female (MZUSP 40844), ibidem, J.B. Mendonça coll., 10.viii.2018, 10.9 m. 1 ovigerous female (MZUSP 41280), ibidem, J.B. Mendonça coll., 4.iv.2014, 12.2 m. 1 male (MZUSP 41281), ibidem, J.B. Mendonça coll., 9.vii.2013, 10.4 m. 1 juvenile female (MZUSP 39582), ibidem, J.B. Mendonça coll., 16.vi.2012, 11.9 m. 1 juvenile female (MZUSP 40481), Ilha da Racha, 20º30’26.5”S, 29º20’48.0”W, J.B. Mendonça coll., 29.xi.2017, 23.7 m. 1 female (MZUSP 40843), ibidem, Ponta Noroeste, 20º29’48.14”S, 29º20’35.21”W, J.B. Mendonça coll., 13.ii.2019, 4 m. 1 female (MZUSP 40958), ibidem, Ponta Noroeste, 20º29’57.8S, 29º20’39.2”W, J.B. Mendonça coll., 16.vii.2012, 15.3 m. 1 juvenile male (MZUSP 41282), ibidem, Ponta Norte, Crista do Galo, 20º29’14.8”S, 29º20’13.9”W, J.B. Mendonça coll., 21.v.2014, 15 m. 1 male (MZUSP 41299), ibidem, Praia do Lixo, 20º31’29.8”S, 29º19’43.9”W, J.B. Mendonça coll., 25.x.2014,. 13.7 m. 1 female (MZUSP 41277), ibidem, J.B. Mendonça coll. 4.xi.2014,. 15.4 m. 1 juvenile female (MZUSP 41406), Martin Vaz Archipelago, 20º30’45.7”S, 29º18’21.9”W, J.B. Mendonça coll., 24.vii.2013, 12.3 m.

Size of largest male: cl 11.5 mm, cw 17 mm; largest female: cl 16 mm, cw 24 mm.

Comparative material examined. Paractaea nodosa: United States: Gulf of Mexico: 1 male (USNM 242831), Florida, 25º17’16”N, 82º52’10”W, 2.xi.1982, 44.2 m. Martinique: 1 male (MZUSP 17294), IGMAR 3 Expedition, stn 418, 14º43.94’N, 60º51.38’W, IFREMER coll. 14.ix.1994, dredge [J. Poupin don.]. Brazil: Ceará: 1 male (MZUSP 16945), Canopus Bank, 120 miles off the coast of Fortaleza, J. Coltro coll., xi.2005, rocky bottom. Bahia: 1 female (MZUSP 8373), R/V “Almirante Saldanha”, stn 2051, Royal Charlotte Bank, around 16º09’54.2”S, 38º23’16.5”W, H.R. Costa coll. Espírito Santo: 1 female (MZUSP 5299), 20º44’S, 40º25’W, S. Rodrigues coll., 20.v.1967. 2 males, 2 females (MZUSP 24534), 20º50’578”S, 40º28’253”W, A. Jório coll., 28.iii.2010, 21.5 m. São Paulo: 1 male (MZUSP 42563), Ilha Vitória, D. Lima and V. Cobo coll., 22.iii.2012. Paractaea margaritaria (A. Milne-Edwards, 1868): Central Atlantic: 1 male, 1 female (USNM 112491), St. Helena, Ruperts Bay, 15º55’S, 5º43’39.2”W, A. Loveridge coll., 18.iii.1960. Paractaea africana Guinot, 1976: Central Atlantic: 1 male (USNM Cobo et al. 2002). Brazilian oceanic islands: Fernando de Noronha (Coelho Filho 2006) and Trindade (Serejo et al. 2006; Tavares et al. 2017). This the first record of P. nodosa from Martin Vaz. The record of P. nodosa (as P. rufopunctata nodosa) from Uruguay by Melo (1996) has not been confirmed by Spivak et al. (2019). Paractaea nodosa, reported from Ascension by Rathbun (1930) as Actaea rufopunctata nodosa, a record repeated subsequently by several authors as P. rufopunctata nodosa, actually refers to P. africana (see Manning & Chace 1990).

Ecological notes. Paractaea nodosa occurs in hard bottoms, such as corals and under rocks. Also found in rubble, shell and occasionally mud to depths of 220 m. It has also been found associated with the sponge Amphimedon viridis (see Alves et al. 2012c). In Trindade and Martin Vaz, P. nodosa was found among algae and under rocks, between 10 m and 23 m. The nodular and grooved aspect of the carapace and its mottled coloration pattern help to conceal the crab by matching its rocky, coralline background.

Remarks. Manning & Chace (1990) assigned the material of Paractaea from the Ascension Island to P. africana Guinot, 1976 (as P. rufopunctata africana Guinot, 1969. See also De Grave et al. 2017), a species also known from West Africa.

Differently, the Trindade specimens clearly belong to P. nodosa, a species known from several localities along the western Atlantic. Paractaea nodosa is best recognized by having distinctly wider intralobular grooves on the carapace and hence more distinctly spaced carapace lobules, whereas the carapace lobules are much closer to one another in P. africana (Fig. 40A–J) (see also Guinot 1976: 253). Additionally, the 1P lobule is almost completely divided longitudinally in P. nodosa – horseshoe-shaped (less so divided in some very small specimens) (Fig. 40D, G), whereas the 1P lobule is almost completely entire in P. africana (Fig. 40J).