Distribution patterns of copepods (Crustacea: Copepoda) in percolation water of the Postojnska Jama Cave System (Slovenia)

Distribution patterns of copepods (crustacea: copepoda) in percolation water of the postojnska jama cave system (Slovenia). Zoological Studies 43(2): 206-210. In the last decade, the biodiversity of groundwaters, including karstic systems, has become intensively studied in Slovenia. We have especially focused on stygobitic copepods which inhabit small fissures and cracks in the so-called vadose (or unsaturated) zone, i.e. the space between fossil cave galleries and the surface. The upper layer of this zone is called the epikarstic zone. Epikarstic species can be collected in trickles of percolating water as well as in the pools filled with it. Faunal samples, along with water for physical and chemical analyses, were collected once per week over a period of 1 yr. Twenty-three taxa of copepods were recorded from the trickles and pools in 3 caves of the Postojnska Jama Cave System. Four taxa of Cyclopoida and 19 taxa of Harpacticoida were recognized. Eight harpacticoid species are probably new to science and belong to 7 genera. We collected 13 species in Postojnska jama, 14 species in Pivka jama, and 11 species in Crna jama. The survey of both trickle and pool habitats in the 3 caves showed qualitative and quantitative differences between them. In Postojnska jama, large differences in the number of copepod species as well as in their abundance were recorded between the 2 habitats. In the other 2 caves, species compositions were similar, but there was a difference in the frequency of specimens.