Ophiothela Verrill, 1867

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 : 18

Genus Ophiothela Verrill, 1867

Type taxon. Ophiothela mirabilis Verrill, 1867 originally described as Ophiothrix (Ophiothela) mirabilis .

Diagnosis. Radial shields very large, covering most of the disc. Ventral side of arms and disc covered by skin, usually obscuring the arm plates and scales. Dorsal arm plates covered by granules. Arm spines mostly turned downward, armed with thorns or hooks ( Verrill 1867).

Comments. In the original description, Verrill (1867) mentions that the adoral shields are all in contact, forming a continuous ring around the mouth. This feature was not used here for two reasons: i) the ventral side of the disc may be covered with a skin, obscuring the oral and adoral shields, making them difficult to see, and ii) some specimens did not have skin covering the ventral disc surface, exposing ventral arm plates between the adoral shields radially, contradicting the original description. This character needs revision. Ophiothela differs from Ophiothrix in having the arms distinctly covered with a membranous skin, dorsal surface with granules ( Verrill 1867), and arms more flexible in the vertical plane ( Clark 1966). Ophiothela was confined to Pacific waters ( Clark 1976b), but recently introduced populations have been described in the Atlantic ( Hendler et al. 2012). Its presence has changed the appearance and ecology of coral reefs as the species is often associated with gorgonians and sponges ( James 1995; Goh et al. 1999; Hendler et al. 2012). The implications of this association are still unclear due to the limited number of studies. One laboratory based study suggests that the coral might gain some benefit from this association through the removal of sediment build-up due brittle star movement ( Sneli 1985). Ophiothela presently includes six species ( Stöhr et al. 2016) with one recorded from Brazil ( Barboza & Borges 2012): Ophiothela danae Verril, 1867 . However, another species, O. mirabilis , was recorded by Hendler et al. (2012) and Mantelatto et al. (2016) and O. cf. mirabilis by Alitto et al. (2016).