Astropecten marginatus Gray, 1840

Gondim, Anne Isabelley, Christoffersen, Martin Lindsey & Pereira Dias, Thelma Lucia, 2014, Taxonomic guide and historical review of starfishes in northeastern Brazil (Echinodermata, Asteroidea), ZooKeys 449, pp. 1-56 : 10

Astropecten marginatus Gray, 1840 Figures 6a-e, 12b

Astropecten marginatus Gray, 1840: 181. Tommasi 1958: 14, pl. 2, fig. 5; 1970: 5, fig. 15. Brito 1962: 3; 1968: 7, pl. 4, fig. 1. Lima-Verde 1969: 11. Carrera-Rodrigues and Tommasi 1977: 88-89. Tommasi et al. 1988: 5. Nomura and Fausto Filho 1966: 19. Gondim et al. 2008: 155. Lima and Fernandes 2009: 58. Xavier 2010: 75.

Astropecten ciliatus Grube, 1857: 340.

Astropecten richardi Gary, 1840: 181.

Astropecten orans Sluiter, 1895: 54.

Material examined.

Rio Grande do Norte: Areia Branca, Ponta do Mel, 2 spec., UFPB/ECH.1842, 23.VI.1982. Paraíba: Cabedelo, Miramar Beach, 1 spec., UFPB/ECH.1840, 03.II.1983; João Pessoa, 7°7'23,3"S; 34°48'27,9"W, 1 spec., UFPB/ECH.1839, 14.IX.1980; João Pessoa, Tambaú Beach, 1spec., UFPB/ECH.864, 03.X.2007. Pernambuco: Goiana, Catuama, UFPB/ECH.1427, 1 spec., 31.X.1982.

Type locality.

Unknown ( Clark and Downey 1992).

Description.

Body flattened. Five broad, triangular arms (Fig. 6a, b). Abactinal surface covered by paxillae arranged in regular transversal rows. Circular madreporite positioned marginally in one of the abactinal intermediate areas. Carinal paxillae slightly smaller than the adradials (Fig. 6d). Paxillae small with 6-8 central spinelets and 12 marginal spinelets, all short and blunts. Superomarginal figs granulose, broader (~3.89 mm) than long (~2.00 mm) (Fig. 6c, d). Inferomarginal figs granulose, with two thick, blunt, parallel spines of similar length (~3.92 mm) and one small spine positioned laterally in relation to the other two. These spines form a well defined marginal bundle. Actinal surface with inferomarginal figs partially naked, having two series of marginal spines positioned laterally and one other marginal series with four thin, elongate, and flattened spines (~1.66 mm), located behind the aboral marginal row of spines (Fig. 6e). Adambulacral figs with a series of small spines on the proximal face and three long, narrow, and flattened adambulacral spines, the median of which is longest and widest. Six elongate, narrow, and pointed oral spines (~1.67 mm). Ocular fig small and bilobed.

Colour. Dorsally either blue with white margins ( Clark and Downey 1992) or uniformly orange-coloured ( Benavides-Serrato et al. 2011). Most specimens collected in northeastern Brazil vary from cream-coloured to grayish. Dried specimens become white.

Distribution.

Costa Rica, Puerto Rico, Colombia, Venezuela, Guyana, and Brazil ( Tommasi 1958, Clark and Downey 1992, Hendler et al. 1995, Alvarado et al. 2008, Benavides-Serrato et al. 2005, 2011). In Brazil: CE, PB, PE, RJ, SP, SC, and RS ( Bernasconi 1955, Brito 1962, Lima-Verde 1969, Netto 2006, Gondim et al. 2008, Lima and Fernandes 2009, Xavier 2010). This is the first record for the littoral of Rio Grande do Norte. From 1 to 130 m in depth ( Clark and Downey 1992).

Remarks.

Astropecten marginatus differs from the remaining species of the genus known from Brazil for having large, triangular arms and two long, thick and blunt spines on each inferomarginal fig. Unlike other species of Astropecten , Astropecten marginatus shows little morphological variation in characters considered of taxonomic interest ( Walenkamp 1976). We observed both juveniles (R = 11.73 mm) and adults (R = 81.41 mm).

Ecological notes.

This species lives in substrates containing sand or sand with mud ( Ortega et al. 2010). As most species of the genus, it is an active predator with a generalist food diet ( Ortega et al. 2010). This is one of the most common species in northeastern Brazil, being abundant below 2-4 m ( Benavides-Serrato et al. 2011). Together with other species in the genus, populations of Astropecten marginatus suffer great collecting pressures from bottom trawling fishing nets. Presently it is included among the Brazilian species vulnerable to extinction ( Machado et al. 2008).