Two new species of genus Alona Baird, 1843 were found in regions along the south-east border of Asian Russia. Alona irinae sp. nov. was found in a lake in the plain of the Zeya River, a north tributary of the Amur River, and in a lake in the steppe region along the West coast of Baikal. Alona floessneri sp. nov. inhabits saline lake Uvs-Nuur on the border of Russia and West Mongolia, and severa...

Population size is often regulated by negative feedback between population density and individual fitness. At high population densities, animals run into double trouble: they might concurrently suffer from overexploitation of resources and also from negative interference among individuals regardless of resource availability, referred to as crowding. Animals are able to adapt to resource shortag...

A new species of Leberis Smirnov 1989 (Cladocera: Chydoridae) is described based on the material from Ciénaga El Convento (Atlántico Department), Ciénaga Grande de Santa Marta (Magdalena Department), and Laguna Navío Quebrado (La Guajira Department), Colombia. In the Neotropics, Leberis colombiensis sp. nov. could be confused with L. davidi Richard, 1985. But the former differs from the latter ...

A new species of Leydigia Kurz, 1875 (Cladocera: Chydoridae) is described based on the material from Ciénaga Grande de Santa Marta, Magdalena Department, Colombia. L. lourdesae sp. nov. is a member of the subgenus Leydigia (Neoleydigia) Kotov, 2009, having all diagnostic characters of the latter. It could be the closest relative to L. iberica Kotov & Alonso, 2010, having five setae on exopodite...

The biodiversity and the biogeography are still poorly understood for freshwater invertebrates. The crustacean Chydorus sphaericus-brevilabris complex (Cladocera: Chydoridae) is composed of species that are important components of Holarctic freshwater food webs. Recent morphological and genetic study of the complex has indicated a substantial species diversity in the northern hemisphere. Howeve...

The spatial distribution of 39 species Chydoridae, representing seven families, was examined in a stratified Palaearctic lake Poland (Lake Piaseczno). Thirty-one the living that were found to exist exclusively littoral zone. No pelagic zone; this zone, eight identified, but all these also quite abundant Almost Chydoridae and Macrothricidae only littoral, whereas Daphnidae Sididae families compr...