Eudendrium pocaruquarum n. sp. (Hydrozoa, Eudendriidae) from the southeastern coast of Brazil, with remarks on taxonomic approaches to the family Eudendriidae

Eudendrium pocaruquarum, a new species of athecate hydroid referable to the family Eudendriidae, is described from the state of São Paulo, Brazil. The species is very similar to the widespread Eudendrium ramosum (Linnaeus, 1758), differing from it in the smaller size of the large microbasic euryteles. Longstanding problems in the systematics of eudendriid hydroids are noted, and the inadequacies of many early descriptions of species are discussed. The nematocysts provide a supplementary character for discrimination of species of Eudendrium, although information on the cnidome appears to have been sometimes misinterpreted in literature.