Luidia clathrata (Say, 1825)

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 : 5

Luidia clathrata (Say, 1825) Figure 3e-h

Asterias clathrata Say, 1825: 142.

Luidia clathratta Lütken, 1859: 37-39. Rathbun 1879: 150. Bernasconi 1943: 6-7. Tommasi 1970: 8. Magalhães et al. 2005: 63.

Luidia clathrata Lütken, 1859: 37. Tommasi 1958: 9, pl. 2, fig. 1; 1970: 8, fig. 22. Brito 1962: 4; 1968: 11-12, pl. 2, fig. 2. Carrera-Rodriguez and Tommasi 1977: 63-64. Tommasi and Aron 1987: 3. Tommasi et al. 1988: 6. Magalhães et al. 2005: 63. Ventura et al. 2007: 237. Manso et al. 2008: 185, fig. 7a-e. Lima and Fernandes 2009: 58. Xavier 2010: 75.

Material examined.

Paraíba: 6°57'S; 34°41'W, 2 spec., UFPB/ECH.875, 12.II.1981, 26m.

Type locality.

Probably no longer existant ( Clark and Downey 1992).

Description.

Five long and narrow arms (Fig. 3e, f). Abactinal surface paxillar. Lateral paxillae quadrangular, forming three regular rows (Fig. 3g). Carinal paxillae small, smaller than lateral paxillae. Dorsal paxillae rounded, small, with 1-6 short, blunt, central spinelets and 6-18 slender, marginal spinelets. Inferomarginal figs with two long, pointed, conical spines (~2.58 mm), positioned vertically, the inferior one the largest. Actinal surface with inferomarginal figs densely covered with flattened, lanceolate spines (Fig. 3f). A row of short, actinolateral figs, with 1-3 short, lanceolate, divergent spines. Ambulacral figs with three spines placed vertically (Fig. 3h). The adambulacral spine is the smallest, being slightly curved and compressed. Of the two subambulacral spines, the inner one is longer and thicker than the outer spine. Oral spines long (~1.32 mm), thin and pointed, forming dense tufts on the inner angle of the jaw (Fig. 3f). Ocular fig granulose and elongate.

Colour. Abactinal surface bluish-gray, frequently with a darker line occupying the carinal region of the arm and disk. Hendler et al. (1995) cite other colour patters for the abactinal surface: brown, rose and salmon. Actinal surface white or cream-coloured.

Distribution.

Bermuda, Gulf of Mexico, Belize, Honduras, Nicaragua, Panama, Colombia, Venezuela, and Brazil ( Downey 1973, Clark and Downey 1992, Hendler et al. 1995, Alvarado et al. 2008, Benavides-Serrato et al. 2005). In Brazil: PE, BA, RJ, SP, and SC ( Rathbun 1879, Bernasconi 1943, Tommasi 1958, 1970, Brito 1960, 1962, Walenkamp 1976, Magalhães et al. 2005, Lima and Fernandes 2009, Xavier 2010). This study records the species for the first time in the State of Paraíba. From intertidal to 175 m in depth ( Ventura et al. 2007), being most common in depths under 40 m ( Hendler et al. 1995).

Remarks.

Luidia clathrata differs from Luidia alternata alternata for not having the abactinal surface spinulose. It differs from Luidia senegalensis for having only 5 arms and from Luidia ludwigi scotti for not having pedicellariae. According to Walenkamp (1976), the number of central spinelets on the paxillae and of inferomarginal spines increases with ontological development, the maximum numbers being, respectively, 7 and 3. In this study the examined specimen had only two inferomarginal spines, and 1-6 central spinelets on the paxillae. These characters indicate a juvenile individual. According to Hendler et al. (1995), adult individuals may attain 20 to 30 cm in disk diameter. Knott and Hopkins (1998) recognized two morphotypes of Luidia clathrata for the Colombian Caribbean, one with a gray colour and the other with three colours, which were separated by Hopkins and Knott (2010) into Luidia clathrata and Luidia lawrencei . Those authors also established and described a neotype for Luidia clathrata .

Ecological notes.

This species lives in sandy or muddy areas with low hydrodynamism near the coast, such as bays and lagoons, and is also found in mangroves and regions with low salinity. Further away from the coast, it lives in substrates with sand, mud and gravel ( Machado et al. 2008, Benavides-Serrato et al. 2011). It feeds on a great variety of prey, including molluscs, crustaceans, and ophiuroids ( Hendler et al. 1995). Like Luidia alternata and Luidia senegalensis , Ludia clathrata is host for the small polychaete Podarke obscura Verrill, 1873, that lives in the interior of its ambulacral groove. Luidia clathrata may form dense populations, and is thus frequently captured in trawling nets used in shrimp fisheries ( McClintock and Lawrence 1985, Hendler et al. 1995). Presently it is considered to be a species vulnerable to extinction along the Brazilian coast ( Machado et al. 2008).