Geographic isolation, altitude, climate, landscape and habitat are significant predictors of butterfly diversity in mountain ecosystems. Their diversity and its dependence on altitude, aspect (compass bearing) and biogeographic characteristics of the butterflies were surveyed on the karst mountain Biokovo in southern Croatia. The results affirm that there is a high diversity of butterflies in the study area and the species composition and biogeographic elements are more dependent on altitude than aspect of the mountain. The present study indicates that climate, relief and habitat preferences strongly influence the biogeographic features of species and the relationship between species richness per site and altitude, aspect and the altitude-aspect interaction. and Iva Mihoci, Vladimir Hršak, Mladen Kučinić, Vlatka Mičetić Stanković, Antun Delić, Nikola Tvrtković.
Cobitis elongata and Sabanejewia balcanica from the family Cobitidae were collected monthly from September 2004 to October 2005 from the Petrinjčica River in the Danube basin of Croatia. On each sampling date, samples of the macrozoobenthos were taken from three different substrates. The density of the macrozoobenthos was calculated and compared with the diet of the loaches. During all months the most dominant group in the macrozoobenthos and in the guts of the analysed loaches was insect larvae of the family Chironomidae. Ivlev’s index was used as a measure of selectivity for various macroinvertebrate taxa in the fish rations and showed changing selectivity that indicate opportunistic feeding strategies and wide diet overlaps between the species.