Comprehensive revision of Anemonactis (Cnidaria: Anthozoa: Actiniaria: Haloclavidae) in Japan: reestablishment of Anemonactis minuta (Wassilieff, 1908) comb. nov. and description of Anemonactis tohrui sp. nov.

Specimens of the sea anemone Halcampella minuta Wassilieff, 1908, (Actiniaria: Haloclavidae) were collected from several localities in Japan during 2014–2017. Although this species had previously been synonymized with Anemonactis mazeli (Jourdan, 1880) due to its smaller size and fewer tentacles, it was under dispute whether this sea anemone was in fact a different species. In this study, the taxon is redescribed from newly collected material and assigned to the genus Anemonactis Andres, 1881 as Anemonactis minuta (Wassilieff, 1908) comb. nov. Its differences from all considered valid species in this genus are discussed. Furthermore, the Atlanto-Mediterranean species Anemonactis mazeli has been considered cosmopolitan by some authors. However, the study of additional material suggests that most of the previous records of this species in Japanese waters belong to a new species, Anemonactis tohrui sp. nov., proposed herein.