Representatives of the genus Simocephalus,
or "tailless water fleas", are rather large (up to 3.5 mm), non pelagic
Daphniidae. They are abundant in the littoral zone and in submerged aquatic
vegetation in freshwater bodies of smallest to largest sizes all over the world.
These animals are often the dominant species of littoral communities.
This book is the result of a seven-year study (about 10.000 specimens from more than 300 localities have been studied). It summarizes data on morphology and taxonomy of Simocephalus obtained earlier. The key is based on a thorough revision and includes all taxa published to date: 63 specific and subspecific names have been proposed before, 20 of which are regarded as valid names here. For each species a differential diagnosis and accounts of its nomenclature, distribution, and morphology are given. All species except one are illustrated based on original figures.
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