Carybdea alata auct. (Cubozoa): rediscovery of the Alatina grandis type

Abstract

Numerous nominal species have been considered synonymous with Carybdea alata Reynaud, 1830 (cf. Gershwin 2005). A recent revision concluded that several of the species collectively referred to as C. alata are valid and indeed separate species (Gershwin 2005; but see also Bentlage et al. 2010). Additionally, these species (including C. alata) were moved into the genus Alatina Gershwin 2005 (family Alatinidae Gershwin, 2005) because of stark morphological differences they display compared to the other species of Carybdea. In particular, Alatina species possess crescentic phacellae and a rhopaliar niche ostium that is covered by a single upper and two lateral scales (t-shaped sensu Gershwin 2005; cf. Bigelow 1938) compared to a single upper covering scale (heart-shaped sensu Gershwin 2005; cf. Bigelow 1938) and epaulette-like or linear phacellae in the corners of the stomach in Carybdea species. Recent molecular phylogenetic analyses support the separation of Carybdea and Alatina (Bentlage et al. 2010). Alatina grandis posed a problem in Gershwin's (2005) revision, as the type of this species appeared to be lost to science, preventing a closer investigation of its identity. I located a type specimen of the species in the collections of the National Museum of Natural History, Smithsonian Institution (USNM). The purpose of this letter is to draw attention to this important specimen, and highlight directions for future studies on the evolutionary history of the genus Alatina.