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Major histocompatibility complex (MHC) genes are commonly used markers for monitoring adaptive genetic and evolutionary potential of species. In this study, we investigated genetic variation of the MHC class II DRBlocus in the chamois genus Rupicapraby using next-generation sequencing. Sequencing of 102 samples led to the identification of 25 alleles, 11 of which are novel. The high ratio of the relative rates of nonsynonymous to synonymous mutations (dN/dS) suggests a signal of positive selection on this locus. We analyzed patterns of genetic variation within and among 2 subspecies of Northern Chamois and compared them to previously published studies using neutral markers to provide a basis for assessing the effects of demographic processes. Our analyses have shown that alleles are likely to be maintained by balancing selection in different populations with similar frequencies and that this mechanism also works in small, isolated populations that are strongly affected by genetic drift.In this study on the chamois genus Rupicapra, researchers explored genetic variation of the MHC class II DRB locus using next-generation sequencing. The research highlights a strong signal of positive selection at this locus, indicated by the high dN/dS ratio. The study also revealed that balancing selection maintains alleles across different chamois populations, including those that are small and isolated, emphasizing the evolutionary significance of this genetic mechanism.

Morphometric data on Common Terns breeding in Croatia and Slovenia are presented herewith for the first time. 130 breeding adult Common Terns Sterna hirundowere measured between 2016 and 2019 along the Sava and Drava Rivers. Sex was determined for 53 birds: 22 males and 31 females. Significant sexual differences were found for head and bill length, length of bill to skull, and bill depth. Croatian and Slovenian terns had slightly shorter wings and tails compared to birds from the Netherlands, Germany and England and were lighter than birds from Germany and Italy. Head, bill and tarsus lengths were similar to those in north European populations. Contrary to results from Scotland, in our studied population, birds with head and bill lengths >79.0 mm could not be sexed as males reliably.

63 Common Tern Sterna hirundosamples from Croatia and Slovenia were analysed with respect to their genetic diversity and differentiation. Samples originated from two freshwater populations (areas of the rivers Sava and Drava) and one coastal population (Sečovlje Salina). The molecular marker of choice was 709 bp long fragment of the mitochondrial control region, the fastest-evolving part of the mitochondrial genome. 21 haplotypes with 12 polymorphic sites were identified. Overall haplotype diversity was substantial and estimated at 0.8599, while the overall nucleotide diversity was low and estimated at 0.0025. Diversity indices were highest for the Drava population, followed by the Sava and the lowest for the Sečovlje population. Overall genetic structure was significantly low (Fst=0.0377) and attributed to the differences in haplotype frequencies between the populations. The high level of genetic diversity found in continental populations illustrates the importance of their habitats as reservoirs of genetic diversity and calls for their further protection and management.

The paper describes two stranded ziphiids from Croatia: a subadult female (length 430 cm, body mass 610 kg) that was stranded in 2001 and an adult male (length 510 cm, body mass ∼1,000 kg) that was stranded in 2002. Both were confirmed to be Cuvier’s beaked whales (Ziphius cavirostrisCuvier, 1823) from analysis of mitochondrial DNA sequences and osteological features. There are no previous records of Cuvier’s beaked whales from the Croatian part of the Adriatic. The external shape of the head of the female specimen appears to be significantly different from the heads of Cuvier’s beaked whales from other seas. The Croatian specimen exhibited embedded pieces of gravel in the gum tissue around the tip of the lower and upper jaws, which was observed for the first time in a Cuvier’s beaked whale. The presence of the female in shallow coastal waters for several weeks and her boat-positive behaviour are apparently also first records of this kind for the species. The female was found to have ingested several plastic bags which likely caused her death. These are the northernmost findings of this species in the Adriatic Sea.The paper describes two stranded ziphiids from Croatia: a subadult female (length 430 cm, body mass 610 kg) that was stranded in 2001 and an adult male (length 510 cm, body mass ∼1,000 kg) that was stranded in 2002. Both were confirmed to be Cuvier’s beaked whales (Ziphius cavirostrisCuvier, 1823) from analysis of mitochondrial DNA sequences and osteological features. There are no previous records of Cuvier’s beaked whales from the Croatian part of the Adriatic. The external shape of the head of the female specimen appears to be significantly different from the heads of Cuvier’s beaked whales from other seas. The Croatian specimen exhibited embedded pieces of gravel in the gum tissue around the tip of the lower and upper jaws, which was observed for the first time in a Cuvier’s beaked whale. The presence of the female in shallow coastal waters for several weeks and her boat-positive behaviour are apparently also first records of this kind for the species. The female was found to have ingested several plastic bags which likely caused her death. These are the northernmost findings of this species in the Adriatic Sea.

AbstractDomestic equidae display polymorphism within ELA-DRA locus which is not characteristic for other species. We characterised sequence polymorphism present at ELA-DRA locus exon 2 and estimated allele frequencies in two autochthonous breeds, Posavina and Croatian Coldblood. In 88 horses, four different alleles were found, one of them not reported before in horses. The new allele shows non-synonymous mutation at position 65 (T→A) causing amino acid change (Phe→Tyr) in antigen binding site and synonymous mutation at position 105 (C→T). Our findings emphasize the importance of DRA polymorphism among equids and some specific DRA frequency pattern potentially specific in draught horses.