53 Isarachnanthus nocturnus (den Hartog, 1977)

Cerianthus natans: Verrill 1901: 47

Ceriantheopsis sp. Pax 1924: 94, 118-120

Arachnanthus nocturnus den Hartog, 1977: 221-230; Cairns et al. 1986: 192-193; Uchida and Soyama 2001: 142, 150, 152 Wirtz et al. 2003: 115-116;

Isarachnanthus nocturnus: Molodtsova 2000: 15,17; Molodtsova 2003: 251-252; Stampar et al. 2012: 1-9

Isarachnanthus sp. Rodriguez et al. 2011: 51; 52, 54

Tessera gemmaria Goy, 1979: 288-289; Rodriguez et al. 2011: 51-55; Stampar et al. 2015c: 2162

Type locality.

Piscadera Bay, Curaçao, Dutch Caribbean.

Distribution.

Caribbean Sea, South Atlantic (Argentina; Brazil), at 1-20 m depth.

Remarks.

This species was described by den Hartog (1977) based on specimens from Curaçao . The specific epithet is related to the nocturnal behavior of this species. This is the most studied species of the genus, as the larval development has been described and the taxonomy has been reviewed with molecular data (Stampar et al. 2012, 2015c). Molodtsova (2003) argued that this species is only a synonym of Isarachnanthus maderensis, however, based on molecular and micrometric data (Stampar et al. 2012) it has been shown that these two species are distinct.

Type material.

Naturalis Biodiversity Center, Leiden (former Rijksmuseum van Natuurlijke Historie) - RMNH.COEL.11364 (Holotype).