Corrected identity of the alien sea anemone Cereus pedunculatus (Pennant, 1777) (Actiniaria: Sagartiidae) in South Africa

Miranda N. Andersen, Marymegan Daly, Tamara B. Robinson. Zootaxa, 5821 (4), 451–468. DOI: 10.11646/zootaxa.5821.4.1

Abstract

Inconspicuous and cryptic invertebrates are often overlooked due to taxonomic challenges associated with identifying them. This is true of an alien sea anemone known from South Africa. Originally identified as Sagartia (now Cylista) ornata (Holdsworth, 1855), the anemone was first documented in Langebaan Lagoon Marine Protected Area in 2001 and has since spread within the lagoon. In recent years, questions have been raised about the validity of the species determination. We used a combination of histology, cnidom assays, specimen dissections, and molecular analyses to evaluate the identity of specimens previously identified as C. ornata and determined that they represent a population of the European daisy anemone, Cereus pedunculatus (Pennant, 1777). This marks the first documented occurrence of C. pedunculatus outside its native range.