Palythoa Lamouroux, 1816

Low, Martyn E. Y., Sinniger, Frederic & Reimer, James Davis, 2016, The order Zoantharia Rafinesque, 1815 (Cnidaria, Anthozoa: Hexacorallia): supraspecific classification and nomenclature, ZooKeys 641, pp. 1-80 : 5-6

Palythoa Lamouroux, 1816

Palythoa Lamouroux, 1816: 359.

Corticifera Le Sueur, 1817: 178.

Polythoa Schweigger, 1819: 100 [incorrect spelling].

Polythea Gistel, 1848: 181 [incorrect spelling].

Gemmaria Duchassaing de Fonbressin and Michelotti, 1860: 55.

Polythoa (Corticithoa) Andres, 1883a: 521, 535-538.

Polythoa (Gemmithoa) Andres, 1883a: 521, 532, 533.

Parapalythoa Verrill, 1900: 560.

Protopalythoa Verrill, 1900: 562.

Haplotella Stechow, 1919: 853.

Type species.

Palythoa [sic] stellata Lamouroux, 1816 [= Alcyonium mammillosum Ellis, in Ellis & Solander, 1786], by subsequent designation by Haddon and Shackleton (1891b: 691) (see also discussion in Appendix 3).

Gender.

Feminine.

Diagnosis.

Colonial brachycnemic zoantharians with sand/detritus incrustation in the ectoderm and mesoglea. Currently, all species except for two described are zooxanthellate ( Irei et al. 2015).

Remarks.

Specimens examined with a sphincter muscle of linear mesogleal type ( Swain et al. 2015).

Protopalythoa was originally separated from Palythoa based on primarily polyp shape. Pax (1910) recommended merging Palythoa and Protopalythoa , and he defined three groups; “immersae”, “intermediae” and “liberae”, which have no taxonomic rank (see Ryland and Lancaster 2003). In 1923, Carlgren adopted this inclusive nomenclature. Similarly, Burnett et al. (1997) discussed the need to merge these genera but retained Protopalythoa . Ryland and Lancaster (2003) also discussed this issue and argued to keep Protopalythoa citing additional characters (zooxanthellate eggs in Protopalythoa ; afterwards potentially observed in Palythoa spp. (Shiroma et al. 2010)). Herein, based on the several recent molecular studies ( Sinniger et al. 2005, Reimer et al. 2006, 2007b, 2012a), we formally synonymise Palythoa and Protopalythoa , with Palythoa having priority.

Although at least 272 species-group names have been established in the genera Palythoa and Protopalythoa in the literature (see Fautin and Buddemeier 2008), with more research, these species-group names will likely be found to be synonyms-the result of high level of intraspecific morphological variation (see Burnett et al. 1994, Reimer et al. 2006, Hibino et al. 2014).