Ophiactis quinqueradia Ljungman, 1872

Gondim, Anne I., Alonso, Carmen, Dias, Thelma L. P., Manso, Cynthia L. C. & Christoffersen, Martin L., 2013, A taxonomic guide to the brittle-stars (Echinodermata, Ophiuroidea) from the State of Paraiba continental shelf, Northeastern Brazil, ZooKeys 307, pp. 45-96 : 60-61

Ophiactis quinqueradia Ljungman, 1872 Figure 8 a–f

Description.

Five arms. Disk circular to pentagonal (dd = 2.48 to 7.62 mm). Covered by imbricating scales of irregular sizes. Scales at center of disk smaller, the largest on interradial field and mainly on lateral margins of radial shields (Fig. 8a). Sparsely distributed small spines on aboral region of disk. Radial shields long and separated over almost full length by three long scales (Fig. 8f). Ventral interradius covered by small spines on small and imbricating scales (Fig. 8b). Bursal slits long and wide. Oral shields long, diamond-shaped, proximally enlarged and distally narrow (Fig. 8c). Adoral shields large, laterally wide. Two or three small, spatulate, oral papillae, distal papilla broader and proximal papilla slightly curved towards the interior of the mouth (Fig. 8c). Dorsal arm plate wider than long, rectangular, with proximal margin rounded (Fig. 8d). Ventral arm plate hexagonal (Fig. 8e). Five or seven serrated arm spines, with a crown of denticles at tip. First dorsal spine small, second largest, and remaining decrease in size in the ventral direction. Single tentacle scale spatulate (Fig. 8e).

Distribution.

The Bahamas, the islands off southern Florida, off Mississippi, Texas offshore reefs, the Antilles, Mexican Caribbean, Cuba, Belize, Panama, and Brazil ( Hendler et al. 1995, Durán-Gonzáles et al. 2005, Hernández-Herrejón et al. 2008). In Brazil from Maranhão, Ceará, Rio Grande do Norte, Pernambuco, Alagoas ( Albuquerque 1986, Gondim et al. in press), and Espírito Santo ( Tommasi 1970). This is the first record for the State of Paraíba. Intertidal to 640 m. Recorded between 11 and 34 m in the present study.

Remarks.

This species lives on bottoms of mud, sand, gravel or corals, being very common in sponges ( Tommasi 1970). According to Hendler et al. (1995), it is an endocommensal of sponges. In Cuba, concentrations of 200 to 300 individuals of Ophiactis quinqueradia were recorded as endocommensal of sponges Agelas sp. ( Abreu-Pérez et al. 2005), Verongia lacunosa (Lamarck, 1816) and Neofibularia notitangere (Duchassaing and Michelotti, 1864) ( Hopkins et al. 1977, Kissling and Taylor 1977, Hendler 1984). In the examined specimens a dorsal arm plate was sometimes subdivided into two or three small plates of irregular shapes.