Ophioderma Müller & Troschel, 1840

Alitto, Renata A. S., Bueno, Maristela L., Guilherme, Pablo D. B., Domenico, Maikon Di, Christensen, Ana Beardsley & Borges, Michela, 2018, Shallow-water brittle stars (Echinodermata: Ophiuroidea) from Araçá Bay (Southeastern Brazil), with spatial distribution considerations, Zootaxa 4405 (1), pp. 1-66 : 11

Genus Ophioderma Müller & Troschel, 1840

Type taxon. Ophioderma longicauda (Bruzelius, 1805) originally described as Asterias longicauda .

Diagnosis. Disc with granules. Four bursal slits per interradius, typically the distal slightly wider than the proximal. Conical and pointed teeth. Six to 13 arm spines, short, flattened and appressed, shorter than an arm segment. Two tentacle scales ( Ziesenhenne 1955; Tommasi 1970; Albuquerque 1986).

Comments. Ophioderma was described in 1840, however, it was considered an unstable genus without a clear diagnosis, leading many researchers to use Ophiura ( Lyman 1860, 1882). Only in the 20th century were many species organized and formally separated from Ophiura ( Clark 1915; Clark 1976b; Melville 1980). Ophioderma is now well-supported and comprises a large, widespread genus of brittle stars ( Pineda-Enríquez et al. 2013). Traditionally, the characters used to separate the species included the shape of disc granules and the extent to which the granules cover underlying plates, disc size, arm length, shape and degree of fragmentation of dorsal arm plates, number and shape of arm spines, as well as colour ( Hendler et al. 1995). However, these characters are often variable, causing difficulties in correct identification ( Stöhr et al. 2009). Studies detailing morphological diagnostic characters, along with molecular analysis, have greatly contributed to distinguishing these species and have revealed divergent lineages ( Stöhr et al. 2009; Boissin et al. 2011). Ophioderma can be found on coral reefs, seagrass, coral rubble and under rocks, typically occurring in shallow water to 50 m, and restricted to tropical and temperate seas ( Pineda-Enríquez et al. 2013). Ophioderma presently includes 37 species ( Stöhr et al. 2016) with six recorded from Brazil ( Barboza & Borges 2012): O. appressa ( Say, 1825) , O. besnardi Tommasi, 1970 , O. brevispina ( Say, 1825) , O. cinerea Müller & Troschel, 1842 , O. divae Tommasi, 1971 , and O. januarii Lütken, 1856 .