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.
Inter-population variability within Sabanejewia populations from the western Balkans, and their phylogenetic position in comparison to other European populations were investigated. Of 79 samples analysed, 51 unique haplotypes were identified. Network analysis divided thirteen populations from five river basins into two clusters: cluster I was composed of populations from the Vardar drainage and tributaries of the neighbouring River Morava (River Danube basin), while cluster II contained the River Timok (eastern Serbia) and all the River Sava populations. The only locality that housed haplotypes of both clusters was the River Kutinska reka in the upper Morava basin. When compared with the haplotypes reported in former studies, both clusters fell within the ‘Danubian-Balkanian complex’. Cluster II was included in the most heterogeneous sub-lineage S. montana – S. bulgarica – S. balcanica (III), while cluster I was related to the sub-lineages S. doiranica – S. balcanica (II) and S. balcanica (VI). Recently published haplotypes from the Croatian Sava (rivers Petrinjčica and Rijeka) and Drava (rivers Drava and Voćinska) basins, as well as Czech and Slovak individuals from the Danube and Tisza river basins were included. The River Drava showed the same population subdivision as the River Kutinska reka.