Prymnesium faveolatum sp nov (Prymnesiophyceae), a new toxic species from the Mediterranean Sea

A new marine species of Prymnesium is described based on cultured material originating from a sublittoral sample collected on the eastern French Medit erranean coast. Prymnesium faveolatum sp. nov, exhibits typical generic cha racters in terms of cell morphometry, swimming mode and organelle arrangeme nt. Organic body scales, present in several proximal layers, have a narrow inflexed rim and are ornamented with a variably developed cross. Scales in the single distal layer have an upright peripheral rim and an alveolate pat tern of ridges. This new species appears to be widely distributed in the Me diterranean Sea. On the basis of scale ornamentation, two groups are recogn ized within those Prymnesium species described by electron microscopy, a se paration hypothesized to be related to ploidy level. Preliminary toxicity t ests indicate that P. faveolatum is a toxic species.