Additional shallow-water thecate hydroids (Cnidaria: Hydrozoa) from Guadeloupe and Les Saintes, French Lesser Antilles

摘要

This report supplements an earlier account on the hydroids of the Guadeloupe archipelago, and records 31 additional species of thecates. Among them, Halecium calderi sp. nov., Antennella armata sp. nov., and Antennella incerta sp. nov., are described. Laomedea tottoni Leloup, 1935 is redescribed and reassigned to the genus Clytia Lamouroux, 1812. Its synonymy is broadened upon inclusion of Clytia laxa Fraser, 1937. Hebella venusta (Allman, 1877) is considered valid based on comparison with related species, and its gonotheca is described for the first time. Two sympatric varieties of Sertularella diaphana (Allman, 1885), easily separable morphologically and by their cnidome composition, are discussed. Sertularella ornata Fraser, 1937 is recorded for the second time and is fully redescribed. Its name is actually a junior synonym of S. fusiformis (Hincks, 1861) f. ornata Broch, 1933, and it is here referred to as S. fraseri nom. nov. Sertularia thecocarpa Jarvis, 1922, Sertularella minuscula Billard, 1924, Sertularella parvula Mammen, 1965, and Sertularia stechowi Hirohito, 1995 are placed in the synonymy of Sertularella tongensis Stechow, 1919, the latter being transferred to the genus Sertularia Linnaeus, 1758. Sertularia ephemera nom. nov. is proposed as a replacement name for Sertularia tongensis Stechow, 1919. Aglaophenia postdentata Billard, 1913 is confidently recorded from the Atlantic for the first time. Dentitheca dendritica (Nutting, 1900) is redescribed, and additional notes on Macrorhynchia clarkei (Nutting, 1900) are provided. All the species discussed herein are new records for the study area. Illustrations are given for each species and data on the nematocyst complement and size of capsules are given when necessary. The number of hydroid species reported from the study area is raised to more than eighty. Hydroids of the Caribbean are moderately well known faunistically, though continuous discovery of new species is likely, the species composition being certainly richer than currently reported.