Isidella Gray, 1858

Cairns, Stephen D., 2018, Deep-Water Octocorals (Cnidaria, Anthozoa) from the Galapagos and Cocos Islands. Part 1: Suborder Calcaxonia, ZooKeys 729, pp. 1-46 : 26-27

Genus Isidella Gray, 1858

Isidella Gray 1858: 283; Kükenthal 1919: 564; 1924: 414; Bayer 1956: F222; Bayer and Stefani 1987a: 51 (key to genus); 1987b: 941 (key to genus); Bayer 1990: 207-208; Etnoyer 2008: 543; Brugler and France 2008: 126-127 (inverted gene order); Watling et al. 2011: 76, fig. 2.11 (map); Dueñas et al. 2014: 20.

Type species.

Isis elongata Esper, 1788, by monotypy.

Diagnosis.

Colonies sparsely branched, dichotomously or trichotomously from nodes, resulting in a uniplanar colony; internodes long and hollow. Polyps non-retractile, cylindrical, armed with stout needles placed longitudinally in body wall. Spiny pharyngeal rodlets present.

Distribution.

Northeast Atlantic (including Mediterranean), New England Seamounts, eastern Pacific from California to Alaska, Hawaii, Galápagos, 400-2593 m deep ( France 2007).

Remarks.

Including the species described below, there are currently six species in the genus, three of which occur in the Pacific. The genus was most recently keyed and discussed by Bayer (1990).

Using one or two mitochondrial genes and six species (most of them undescribed), France (2007) and Dueñas et al. (2014: Figure 2) indicated that Isidella was not monophyletic. Both papers imply that branching pattern, which has traditionally been used to distinguish keratoisidinine genera, is not a reliable character.