[Proposition of a new classification of the phylum of the protozoa Ciliophora Doflein, 1901].

It is proposed to use all the presently available molecular, ultrastructural, biological and ecological data on ciliates for the new classification of this group of protists. On the basis of the cortical organization and the mode of cilia anchoring as well as the degree of conservation of the cortical pattern during the process of morphogenesis, eleven classes (Karyorelictea, Heterotrichea, Hypotrichea, Oligotrichea, Plagiopylea, Colpodea, Litostomatea, Vestibuliferea, Phyllopharyngea, Nassophorea and Oligohymenophorea) have been distinguished. These classes, in turn, were, according to the "shell theory" of Fleury and coworkers (1992), grouped into three subphyla: Tubulicorticata (presence of the cortical microtubular lattices), Filicorticata (characteristic ecto-endoplasmic microfibrillar boundary) and Epiplasmata (presence of a sub-membraneous epiplasmic layer).

The feeding apparatus of a chitinivorous ciliate.

The chitinivorous ciliate Ascophrys, an ectosymbiont of the shrimp Palaemon serratus, is enclosed by a thick cyst wall except for a ventral hiatus exposing a circular area of exoskeleton to the interior of the cyst. The exoskeleton underlying the cyst wall remains intact, but the circular area of exoskeleton is dissolved enzymatically and ingested. The feeding ciliate forms a cavity in the exoskeleton into which it sinks.

A newly revised classification of the protozoa.

The subkingdom Protozoa now inclues over 65,000 named species, of which over half are fossil and approximately 10,000 are parasitic. Among living species, this includes approximately 250 parasitic and 11,300 free-living sarcodines (of which approximately 4,600 are foraminiferids); approximately 1,8000 parasitic and 5,100 free-living flagellates; approximately 5,600 parasitic "Sporozoa" (including Apicomplexa, Microspora, Myxospora, and Ascetospora); and approximately 2,5000 parasitic and 4,700 free-living ciliates. There are undoubtedly thousands more still unnamed.