Additional notes on Clathrozoella drygalskii (Vanhöffen, 1910) (Cnidaria, Hydrozoa)

Abstract

Study of the material of Clathrozoella drygalskii (Vanhöffen, 1910), a hydroid initially referred to the thecate hydroids but probably better classified in athecate hydroids along with such families as Hydractiniidae and Solanderiidae, has been continued with the help of sectioned material. Owing to the conditions of the material available, sectioning proved to be quite difficult; this combined with the poor condition of preservation provided inadequate and inconclusive results, as a result of which the taxonomic position of this enigmatic genus could not be definitely clarified. However, available evidence seems to suggest that the genus Clathrozoella Stechow, 1921, contains at least three species of which one, C. drygalskii, occurs in Antarctic, New Zealand and Australian waters, a second to the south of Stewart Island south of New Zealand, and a third exclusively (so far) in the Antarctic. Histological details of the two additional species are still lacking and information on the cnidome of the three species is still insufficient.