Syracosphaera pemmadiscus sp. nov. (Prymnesiophyceae), an extant coccolithophore from the southwest Pacific Ocean near New Zealand

摘要

A new taxon, Syracosphaera pemmadiscus sp. nov., collected from the southwest Pacific Ocean near New Zealand, was described based on the morphological structure of both exo-and endothecal coccoliths. Both the elliptical exo- and endothecal coccoliths of Syracosphaera pemmadiscus were very small (<2 μm). The exothecal coccoliths were dimorphic, while the body coccoliths (muroliths) were monomorphic. Muroliths were deeply fluted with their upper wall flared outward into a distal flange, while the lower wall extended outward into a proximal flange. This new species has only been recorded in the Subantarctic and Subtropical Front waters to the east of New Zealand. Because Syracosphaera pemmadiscus sp. nov. has features typical of members of the Syracosphaera molischii group, it is proposed that this taxon to be added to this group.