A CONSPECTUS OF THE CLADOCERA OF THE SUBTERRANEAN WATERS OF THE WORLD

A synthesis of current knowledge of the Cladocera living in non-surfac e waters is provided. For all 94 species and subspecies recorded (Dec. 1994) we give information on their ranges, ecological characteristics , and a review of literature data. We also give a historic survey of t he development of concepts, identify categories among groundwater-dwel ling species, and discuss their adaptations and the evolutionary lines present. Of the estimated total of c. 450 non-marine Cladocera of the world, c. 20% may occur in underground aquatic habitats, but true gro undwater forms (stygobionts or stygobites) are relatively few, possibl y not more than 10 species (c. 2.5% of the total). This number may inc rease, as attention is given to subterranean habitats outside Europe.