INTERSTITIAL COMMUNITY COMPOSITION IN SEVERAL MONTANE AND SUBMONTANE STREAMS IN THE WEST CARPATHIANS

Representatives of the hypogean fauna (Crustacea: Cyclopidae, Harpacti cidae, Bathynellacea) predominated in the sediments of montane streams (epirhithron) at higher altitudes (970 m a. s. l.) and in the hypokre non. A considerable part of the interstitial community was represented by Copepoda (50-70%). The abundance of the representatives of the epi gean fauna increased in the floodplain sediments of submontane streams (metarhithron) with increasing distance from springs. At the lowest i nvestigated altitude (425 m a, s. l.) Oligochaeta predominated (40%). Larval Ephemeroptera, Plecoptera and Diptera ranged in frequency betwe en 13 and 23%. The crustaceans predominated in spring and autumn, Olig ochaeta and insect larvae in summer. The highest abundance of hyporheo s in hypokrenon (1300 ind.m(-3)) and metarhithron (1030 ind.m(-3)) was recorded during low discharge of surface water (in the hypokrenon up to 0.5 l.s(-1) while in the metarhithron up to 500 l.s(-1)).