The Prorocentrales (Dinophyceae): I. A comparative account of fine structure in the genera Prorocentrum and Exuviaella

Abstract

A fine-structural survey of three species of Prorocentrum and five species of Exuviaella has shown that there is no basic distinction between the two genera. An earlier proposal that the genus Exuviaella be abandoned and its species incorporated into Prorocentrum is supported by this work. The basic fine structure of the species studied is typical of the dinoflagellates but there are adequate distinctive features to justify the retention of the separate order Prorocentrales. Within the order some ultrastructural differences noted between species are types of pyrenoid, ornamentation and structure of the thecal plates and presence or absence of trichocysts and fibrillar bodies.