About 114 "species" of Macrothrichidae, Eurycercidae, and Chydoridae (Cladocera, Anomopoda), belonging to 39 genera, have been reported from China, with 14 species in 6 genera in Macrothrichidae, 2 species in one genus in Eurycercidae, and 98 species in 31 genera in Chydoridae. In total, 203 species in 62 genera, 13 families and 4 orders have so far been reported from the country. Of these, 187 are tentatively considered as valid, while 16 are incertae sedis. In reality, many records hide taxonomic problems that remain to be settled. Up to 10 percent of this fauna might be endemic at the species level, but we expect this number to increase pending new, comprehensive studies. No endemic genera fall to be recorded. Most of the several hundreds of taxonomic or biogeeographic papers from which this information was extracted suffer from poor or outdated taxonomy, such that up to half of all species are up for re-evaluation. Detailed morphological examination, but also provoked male production, especially in chydorids, are ways to improve identifications and should be stimulated. On the other hand, the inventory is certainly still incomplete with several tropical-subtropical taxa still to be expected in China. The extreme south and islands are among promising sites that remain to be explored, as well as extreme habitats all over the country. Molecular studies in China started around the beginning or the present decade, and should be multiplied.

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Rapid climate changes may potentially have strong impacts on the ecosystem structure and nutrient dynamics of lakes as well as implications for water quality. We used a space-for-time approach to elucidate such possible effects by comparing data from 1656 shallow lakes (mean depth <3 m) in north temperate Denmark (DK) and subtropical Florida (FL). The lakes were categorized into 7 total phosphorus (TP) classes within the range of 2 to 300 µg L −1. Physicochemical variables showed significant seasonal differences, which can be attributed to different sunlight regimes and temperatures. The FL lakes had overall higher fish biomasses (notably in the littoral zone) but a substantially lower zooplankton biomass and body mass of microcrustaceans, a much lower zooplankton:phytoplankton biomass ratio (lower grazing on phytoplankton), and a markedly lower biomass of benthic invertebrates, indicating much greater control of consumers by fish in the FL lakes. Accordingly, the summer phytoplankton biomass was higher in the FL lakes. Cyanobacteria in summer were proportionally more important in the FL lakes at all TP levels, whereas the proportion of dinophytes, chrysophytes, and cryptophytes was higher in the DK lakes at low TP. Submerged macrophytes occurred at higher TP (>100 µg L −1) in the FL lakes, but coverage was higher in the DK lakes at low TP. We also found lower oxygen saturation in the nutrient-rich FL lakes than in the DK lakes, suggesting lower net ecosystem production in the FL lakes. We discuss our results within the framework of climate warming.

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