HEMIEURYALIDAE Verrill, 1899

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 : 15

Family HEMIEURYALIDAE Verrill, 1899

Type taxon. Hemieuryale von Martens, 1867 .

Diagnosis. Disc covered with thick plates with distinct centrodorsal and primary plates. Typically, one apical papilla flanked by a series of continuous lateral oral papillae. Bursal slits small, placed near margins of oral shields. Arms inserted laterally into the disc. Dorsal arm plates complete or replaced by a mosaic of small plates. Arm spines short and few. Spine articulation composed of two parallel ridges placed at an angle to each other ( Verrill 1899a; Martynov 2010; Gondim et al. 2015).

Comments. Hemieuryalidae has been considered one of the least known families of Ophiuroidea, in regards to ecology, morphology, and phylogeny ( Gondim et al. 2015). A recent study proposed moving Ophiochondrus and Ophiomoeris to Ophiacanthidae based on lateral arm plate morphology ( Martynov 2010). Hemieuryalidae has peculiar ridges on its spine articulations, which are very different from other ophiuroids ( Martynov 2010). The family has also been supported by a molecular phylogeny reconstruction using next-gen sequence-capture methodology ( O’Hara et al. 2017). Hemieuryalids are associated with octocorals ( Gondim et al. 2015) and hydrocorals ( Hendler et al. 1995), but are also found as members of the epifauna ( Borges, 2006). The family is comprised of 84 species distributed across ten genera ( O’Hara et al. 2017). In Brazil, three species are recorded from three genera ( Barboza & Borges 2012; Gondim et al. 2015).