Florenciella parvula gen. et sp. nov. (Dictyochophyceae, Heterokontophyta), a small flagellate isolated from the English Channel

Florenciella parvula (Dictyochophyceae) was isolated from the English Channel in December 2000. In general the cells are spherical, measure 3–6 μm and have two markedly unequal flagella as well as two yellow-brown chloroplasts. The long hairy flagellum pulls the cells through the water and the short flagellum is acronematic. Their morphology and fine structure indicate a close relationship with the Heterokonts. Phylogenetic analysis of the small subunit of the ribosomal RNA gene clearly places F. parvula within the class Dictyochophyceae and more precisely the order Dictyochales, despite the absence of the external skeleton characteristic of this order. The pigment suite consists of chlorophylls a, c2, c3, 19′ butanoyloxy-fucoxanthin, fucoxanthin, diadinoxanthin and β-carotene. This pigment composition is typical of the class Pelagophyceae.