Ophiolepis impressa Luetken , 1859

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 : 51

Ophiolepis impressa Luetken, 1859 Figure 3 a–e, 14b

Description.

Disk circular to pentagonal (dd = 4.26 to 9.82 mm). Covered by large, imbricating scales, surrounded by smaller scales of different sizes and irregular shapes (Fig. 3a). Primary plates conspicuous, central primary plate rounded. Interradius with three rows of large scales. Radial shields triangular, separated distally by three large scales disposed in a triangle, and proximally by a large scale (Fig. 3a). Ventral interradius covered by imbricating scales, slightly smaller and narrower than dorsal scales (Fig. 3b). Bursal slits long and narrow. Oral shields pentagonal, elongate, distal margin convex. Adoral shields broad, enlarged laterally and contiguous along internal median line of jaw. Four to five oral papillae on each side of jaw angle, the three proximal of which are pointed and subequal, the penultimate one is longest and broadest (Fig. 3c). Dorsal arm plate wider than long. Accessory dorsal arm plate reduced and restricted to the first arm segments (Fig. 3f). Ventral arm plate on first segments as large as long, on last segments slightly broader than long, tending to become pentagonal in shape, with lateral margins concave and distal margin rounded (Fig. 3e). Three or four arm spines short and conical, blunt, the two dorsal ones smaller. Tentacle pore large. Two large tentacle scales, the outer one slightly broader than the inner one (Fig. 3e).

Distribution.

Bermuda, the Bahamas, the islands off southern Florida, Texas, the Antilles, Mexican Caribbean, Belize, Honduras, Costa Rica, Panama, Colombia, Venezuela, and Brazil ( Hendler et al. 1995, Laguarda-Figueras et al. 2004, Durán-Gonzáles et al. 2005, Alvarado et al. 2008, Borrero-Pérez et al. 2008, Hernández-Herrejón et al. 2008). In Brazil from Alagoas ( Miranda et al. 2012), and Bahia ( Tommasi 1970, Magalhães et al. 2005). Intertidal to 24 m in deph. In this study they were found for the first time in the State of Paraíba, between 10 and 33m.

Remarks.

According to Hendler et al. (1995), individuals of this species are usually sedentary, but show some nocturnal activity. They live on bottoms with corals and dead shells ( Tommasi 1970), predominantly on sand, under corals and rocks, sometimes occurring on algae. They are moderately palatable for some fish, although their strongly calcified arms furnish some protection against predators ( Hendler et al. 1995). Only some specimens show a small accessory dorsal arm plate, and when present, it is restricted to the first segments. According to Devaney (1974), Lyman transferred Ophiolepis impressa and Ophiolepis pacifica Lütken, 1856 to the genus Ophiozona Lyman, 1865, based only on the supposed absence of the accessory dorsal arm plate. However, Devaney (1974) rejected the new genus proposed by Lyman and placed it in synonymy with the genus Ophiolepis , given that there are no criteria to separate the two taxa. Hendler (1988) questions the use of this character as a synapomorphy of the genus Ophiolepis , since it is expressed in different ways. According to this autor, the expression of accessory dorsal arm plates within and between the different species is variable. Moreover, they are barely discernible or absent in juveniles.