Nematocysts of Chiropsalmus quadrumanus with comments on the systematic status of the Cubomedusae

Abstract

1. Cubomedusae or "sea wasps" have generally been placed in the Scyphozoa, although they differ significantly in morphology from other representatives of the class. This study was undertaken to determine possible differences in the nematocyst complement of Cubomedusae and other scyphozoans. 2. Nematocysts were examined in specimens of the sea wasp Chiropsalmus quadrumanus from South Carolina and Georgia, USA. The cnidome of these medusae consisted of isorhizas, microbasic mastigophores, and heterotrichous microbasic euryteles. 3. Mastigophores occur in hydrozoans and anthozoans but have not been observed in scyphozoans other than sea wasps. Together with recent evidence from life history studies, this difference indicates that the Cubomedusae are sufficiently distinctive to merit recognition as either a separate subclass or class. © 1975 Biologischen Anstalt Helgoland.