Coscinasterias tenuispina (Lamarck, 1816)

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 : 18-20

Coscinasterias tenuispina (Lamarck, 1816) Figure 9i-m

Asterias tenuispina Lamarck, 1816: 561-562.

Asteracanthion tenuispinus Müller & Troschel, 1842: 16.

Asterias atlantica Verrill, 1868: 368. Rathbun 1879: 145.

Asterias (Stolasterias) tenuispina Sladen, 1889: 565, 583.

Polyasterias tenuispina Perrier, 1894: 108.

Lytaster inaequalis Perrier, 1894: 98-99.

Coscinasterias tenuispina Verrill, 1914: 45. Brito 1960: 4; 1962: 2. Netto 2006: 34, fig. 16c, pl. 5b. Ventura et al. 2007: 228.

Coscinasterias tenuispina var. atlantica Verrill, 1915: 20-21. Tommasi 1966: 24-244.

Stolasterias tenuispina Verrill, 1907: 324.

Coscinasterias (Stolasterias) tenuispina Fisher, 1926: 197.

Material examined.

Rio de Janeiro: Cabo Frio, Formoso Beach, 1 spec., MZUSP (without registration number), VII.1956; Cabo Frio, Arraial do Cabo, Brava Beach, 1spec., MZUSP (without registration number), 29.I.2001.

Type locality.

‘I’ ocean eropéen’ ( Clark and Downey 1992).

Description.

Disk small, with 1-3 madreporites (in some cases up to 5 were observed). Six to nine (rarely 5 and unusually 7) thin, elongate (Fig. 9i, j), cylindrical arms, usually of different sizes, the larger ones grouped to one side and the smaller ones to the opposing side. Abactinal figs with one long, conical and pointed spine (~2.17 mm), with base densely surrounded by bivalve pedicallariae with overlapping valves (Fig. 9l). Carinal figs arranged in a regular series. Dorso-lateral figs forming a reticulum. Papular regions occuring on the abactinal and actinal surfaces. Among the abactinal figs, mainly in the intermediate areas, large bivalve pedicellariae are found. Pedicellariae of dorsal spines sessil and with overlapping bivalves, with denteate margins. Oral pedicallariae bivalve (Fig. 9m), consisting of a basal piece into which two valves with smooth margins fit in.

Colour. Specimens from Brazil vary from brown to orange colour ( Ventura et al. 2007). According to Clark and Downey (1992), specimens from the Mediterranean are usually yellow or whitish-yellow with black or brown spots on abactinal surface and crowns of rusty-red pedicellariae. Individuals from the Bermudas, on the other hand, with dorsal surface purple and the oral surface yellow, blue or violet ( Verrill 1915).

Distribution.

North Carolina, Gulf of Mexico, Antilles, Bermudas, Cuba, Brazil, Portugal, Spain, France and Montenegro ( Tommasi 1970, Downey 1973, Clark and Downey 1992, Alves et al. 2002, Waters and Roy 2003, Kascelan and Mandic 2007). In Brazil: BA, ES, and SP, including Abrolhos ( Rathbun 1879, Verrill 1915, Brito 1960, Tommasi 1970, Ventura et al. 2007). Intertidal to 165 m in depth ( Clark and Downey 1992).

Remarks.

Two species of the genus Coscinasterias Verrill, 1870 are known for the Atlantic, Coscinasterias tenuispina and Coscinasterias calamaria (Gray, 1840). The first is widely distributed through the Atlantic and Mediterranean, while the second is restricted to South Africa, Angola, and Madagascar ( Mah 2013). Coscinasterias tenuispina differs from Coscinasterias calamaria for having intercrossing pedicellariae with a well developped terminal tooth (except in some specimens from Brazil). Clark and Downey (1992) suggested a subspecific distinction for these species on the basis of morphological similarities observed in Brazilian and South African specimens. However, according to Waters and Roy (2003) these observations were made on the basis of juvenile specimens and it is thus necessary to undertake new morphological analyses to clarify the close relationships between Coscinasterias calamaria and Coscinasterias tenuispina ( Waters and Roy 2003). In the phylogeographic analysis of Waters and Roy (op. cit.) for species of Coscinasterias , morphological variations were observed between populations from Brazil on the one side and from the Bermudas and the Mediterranean on the other. No morphological variations are observed in the specimens examined by us.

Ecological notes.

Lives in consolidated substrates, including areas with strong hydrodynamism ( Machado et al. 2008). Coscinasterias tenuispina has extra-oral digestion and feeds on epifaunal organisms, mainly mussels ( Ventura et al. 2007). It is a fissiparous species, which presents an annual gonadal cycle and a long period of spawning ( Alves et al. 2002). According to these authors, the preponderance of males in the population of Itaipu Beach ( Niterói /Rio de Janeiro) suggests that assexual reproduction by fission is predominant and, consequently, that the number of clones must be significant. According to Brito (1962), this species is very common in Cabo Frio (Rio de Janeiro). However, since the first record by Rathbun (1879) of Coscinasterias tenuispina for Abrolhos (Bahia), the species has not been cited again off the northeast region of Brazil. As pointed out by Machado et al. (2008), although this species has a wide geographical distribution, its range is discontinuous, probably due to its assexual reproduction, that limits dispersal ability. Presently the species is listed among those vulnerable to extinction, having among the main causes of population decline the constant destruction of its habitat, the erosion of the substrate, the effects of pollutants, the precarious sanitation and the excess of tourists and divers within their range of occurrence ( Machado et al. 2008).