A revised classification of Cryptophyta

The systematics of currently recognized cryptomonad genera is reviewed. Com plete ultrastructural descriptions are provided for each genus, and are bas ed on the most recent observations in the literature. Using ultrastructural , biochemical and molecular data, a classification scheme, which delineates 16 genera, is proposed for the Cryptophyta. This scheme accommodates two c lasses, the Cryptophyceae and the Goniomonadea. These differ primarily in t hat the former possesses a plastidial complex whereas the latter lacks one. Three orders are discussed and are separated on the basis of colour. The o rder Goniomonadales, which consists of a single genus, is aplastidal and co lourless. The order Cryptomonadales has two families and contains the acces sory pigment Cr-phycoerythrin 566 which imparts a brown colour to the cells . The constituent families, Cryptomonadaceae and Campylomonadaceae, are sep arated by variations in the furrow/gullet complex, the inner periplast comp onent (TPC), nucleomorph position, and the type of rhizostyle. The order Py renomonadales contains four families. It is the sister group to the Cryptom onadales and possesses the accessory pigments Cr-phycoerythrin 545, 555, an d these impart a red colour to the cells, or other members that possess Cr- phycocyanin 630, 645, or 569, which impart a blue-green colour to the cells . The four families are separated on the basis of phycobiliprotein type and , where appropriate, a combination of nucleomorph placement, type of IPC, r hizostyle type, and furrow plate type. This scheme accommodates three new f amilies, the Campylomonadaceae, Geminigeraceae, and Chroomonadaceae. (C) 19 99 The Linnean Society & London.