Environmental parameters determining water mite assemblages in Costa Rica.

This paper presents an ecological analysis of the water mite fauna of 350 streams, rivers, springs and standing waters from all main regions, ecosystems and elevations in Costa Rica. From 509 sample sites about 20,000 water mites representing 74 genera in 21 families were collected. 17 habitat types were distinguished and 11 further environmental parameters were measured. The significance of the particular parameters was analysed using canonical correspondence analysis (CCA). Habitat type, elevation, temperature and velocity were identified as major factors determining water mite assemblages. The analyses showed the existence of characteristic water mite coenoses in different neotropical habitats and the suitability of neotropical water mites for bio-monitoring programmes.