Astropecten acutiradiatus Tortonese, 1956

Astropecten acutiradiatus Tortonese, 1956: 323–324, pl.8.

Astropecten acutiradiatus — Brito 1962: 3; 1968: 8; Tommasi 1970: 6, fig. 18; Clark & Downey 1992: 26–27, fig. 9b, pls. 5C, D.

Distribution. Curaçao, Venezuela (Clark & Downey 1992). BRAZIL: Bahia, Rio de Janeiro (Tortonese 1956; Brito 1968; Tommasi 1970; Clark & Downey 1992; Ventura et al. 2007). Depth. 35–66 (475?) m (Clark & Downey 1992; Ventura et al. 2007).

Biological notes. Specimens of A. acutiradiatus live on sandy bottoms and feed mainly on crustaceans and gastropods (Ventura et al. 2007).

Holotype. Museo Civico di Storia Naturale di Genova, C.E. 36017 (Clark & Downey 1992).

Type locality. Baía de Guanabara, Rio de Janeiro, Brazil (Brito 1968) .

Remarks. Despite four years of collection in Baía de Guanabara, Brito and his team never found additional specimens of A. acutiradiatus (Brito 1968) . Ventura et al. (2007) recorded the species for Bahia, but unfortunately, we did not have access to this material to make any further observations.

Astropecten acutiradiatus is poorly known and ontogenetic variation has not been documented. The arms of the holotype are long and narrow, unlike any other Brazilian Astropecten . Clark & Downey (1992) suggested that this species should be considered a subspecies of Astropecten articulatus . Although Tortonese (1956) mentioned the similarity between A. acutiradiatus and A. articulatus, he did not mention characters used to separate these species. A revision with the examination of more specimens is necessary to elucidate this question.