In terms of ichthyology, Bosnia and Herzegovina (BiH) is one of the most interesting parts of Southeast Europe, due to its rich biodiversity and high level of endemism. Despite its relevance, the entire territory has been poorly explored. Here, we provide an updated inventory of the current state of knowledge on fishes, including lampreys, from the freshwaters of BiH by hydrographic basin, with recent distributional data and updated taxonomic status reviewed and compared with previous lists. The checklist was compiled based on the existing scientific and grey literature, technical reports, scientific congresses, academic dissertations, and unpublished/personal observations. In total, 123 species including diadromous and euryhaline fishes have been documented in BiH freshwaters to date. Of these, 110 are primarily freshwater. In comparison to the last published monography (Sofradžija 2009), we present a 9% increase in species number (11 species), resulting mainly from taxonomic re-evaluations of existing taxa on the basis of new information and the adoption of a new changes in the taxonomic status of several species. Among the valid primarily freshwater species, 87 are native and 23 are non-native. A total of 38 endemic species have restricted distribution, and are threatened by numerous anthropogenic pressures. Four species are considered endemic only to BiH: Cobitis herzegoviniensis Buj & Šanda, 2014; Phoxinellus pseudalepidotus Bogutskaya & Zupančič, 2003; Telestes dabar Bogutskaya, Zupančič, Bogut & Naseka, 2012; and T. metohiensis (Steindachner, 1901). In total, 75 genera and 34 families are represented: Leuciscidae is represented by 37 species, the Salmonidae by 13, followed by the Cyprinidae, Cobitidae and Percidae, each with eight species. The native species richness follows a pattern similar to that observed in other southern European countries. A national list of endangered species has not yet been proposed to BiH and management strategies for their protection or conservation are also not implemented. Hopefully, this updated checklist will serve as a basis for future research aimed at understanding the origin and status of conservation of the BiH fishes diversity, and supporting effective management and conservation programmes.

Mountain lakes are sensitive ecosystems that serve as natural indicators of ecological change and conservation needs. This study presents the first ecological assessment of Lake Šator (Bosansko Grahovo, Bosnia and Herzegovina), a glacial lake situated at 1,488 m a.s.l. Field research in July and November 2021 included measurements of physicochemical parameters, water sampling, and analysis of littoral and sublittoral macrozoobenthos. The lake showed oligotrophic conditions with high oxygen saturation (101–134%), low organic load, and stable conductivity (208 µS/cm). Nitrate concentrations increased in November, reflecting seasonal dynamics. The macrozoobenthic community comprised 10 taxa in July (26 individuals) and 11 taxa in November (19 individuals). Characteristic taxa included Sympetrum flaveolum, Asellus aquaticus, Erpobdella octoculata, Limnephilus rhombicus,  Limnephilus flavicornis, Tubificidae, and water mites (Hydracarina). Functional Feeding Groups analysis revealed dominance of predators (42–46%), followed by collectors, shredders, and scrapers, indicating a balanced trophic structure. Saprobic Index values (2.24 in July; 2.14 in November) correspond to β-mesosaprobic conditions, while Shannon–Weaver Index indicated stable but seasonally variable diversity. These findings confirm the good ecological status of Lake Šator with preserved littoral dynamics. Given its sensitivity and limited prior research, the lake should be considered a priority for long-term monitoring and conservation in the Dinaric karst.

Abstract This study presents the first comprehensive ecological assessment of the Dabar River, a small karstic watercourse in the Sanski Most area, using biological indicators focusing on the macrozoobenthos community, microbiological parameters, and ichthyofaunal composition. Sampling was conducted at three sites (headwaters, middle course, and downstream section), applying standard methods for the analysis of macrozoobenthos composition, bacterial abundance (including Escherichia coli), and biological indices (SI, BMWP, ASPT, EBI). The results indicate a good ecological status of the river, particularly in the headwater section, with a slight decline in water quality downstream. A rich and stable benthic fauna was identified, dominated by Gammarus fossarum, Sadleriana fluminensis, and representatives of the EPT groups. Microbiological findings revealed low to moderate levels of contamination, with no presence of fecal bacteria. Dabarska Cave, which hosts endemic subterranean crustaceans and olm Proteus anguinus, represents a particular ecological value of the area. Guidelines for conservation and sustainable management are proposed, including legal protection of the watercourse, pollution control, and the development of ecotourism.

Abstract As an endemic species, Dalmatian barbelgudgeon was introduced into Šatorsko Lake, but it was insufficiently explored at this locality. The aim of this study was to determine seasonal variations of physicochemical parameters of the water in relation to morphometric and hematological parameters of Dalmatian barbelgudgeon from Šatorsko Lake. Physicochemical analysis of the water recorded lower values of temperature, O2 concentration, O2 saturation, electrolytic conductivity and suspended matter in autumn, while other analyzed parameters indicated lower values in spring. The analysis of morphometric parameters (weight, standard length, total length and Fulton’s condition factor) determined higher values of all the parameters during spring, while a significant difference was noted only for Fulton’s condition factor. A statistically significant difference was observed for all erythrocyte lineage parameters (RBC-red blood cells, HB-hemoglobin concentration, HCT-hematocrit, MCV-mean corpuscular volume, MCH-mean corpuscular hemoglobin, MCHC-mean corpuscular hemoglobin concentrations). In white blood cells, a statistically significant difference was recorded for lymphocytes, non-segmented neutrophils and monocytes, while the proportion of segmented neutrophils and basophils was slightly increased in spring. Furthermore, the recorded values of pseudo-eosinophils were equal in spring and autumn. The results of these studies indicate a significant influence of exogenous and endogenous factors on the variability of morphometric and hematological parameters of Dalmatian barbelgudgeon from Šatorsko Lake.

Abstract. Alongside climate change, the introduction of non-native species (NNS) is widely recognized as one of the main threats to aquatic biodiversity and human wellbeing. Non-native species and biodiversity are generally low priority issues on the political agendas of many countries, particularly in European countries outside the European Union (EU). The objectives and tasks of this study were to address the policy regulation, education level, education practices, and socioeconomic perceptions of NNS in the Balkans. A questionnaire-based survey was conducted in Albania, Bosnia and Herzegovina, Montenegro, North Macedonia and Turkey (Balkan EU candidate and potential candidate members), in Croatia and Greece (Balkan EU Member States) and Italy (non-Balkan EU Member State). The EU Alien Regulation (1143/2014) concerning NNS is implemented in EU Member States and Montenegro, whereas Albania, Bosnia and Herzegovina and Turkey have not reported specific policy regulations for NNS. Permanent monitoring programmes specifically designed for NNS have not yet been established in the EU Member States. Most countries tackle the issue of NNS through educational activities as part of specific projects. Education level is indicative of the implementation of NNS policy regulation, and efforts are needed for the proper development of relative study programmes. Public awareness and educational preparedness concerning NNS in the Balkans were identified as poor. Strong programmes for management and education should be developed to increase public awareness to prevent further biodiversity losses in the Balkan region.

: The aim of this study is to examine the effect of plant fat sources in sheep feed on somatic cells and the total number of microorganisms in raw milk samples obtained from 210 sheep, breed Pramenka in Una-Sana Canton. The research was conducted in three periods: winter, spring and summer. The herd was divided into experimental and control groups of sheep. In the experimental groups of sheep in each period of the study, omega-3 supplements were added to the diet, namely extruded flaxseed in the amount of 3.5%. The influence of added omega-3 supplements on the microbiological parameters of raw sheep milk, which was milked from experimental and control groups of sheep every fifteen days of the experiment in all periods of the study, was examined. Analysis of variance (ANOVA) found that during the winter and summer feeding period there is a statistically very significant influence of both experimental factors (treatment and period) on the total number of microorganisms and somatic cells in raw sheep milk (p <0.001). In the spring diet in somatic cells, factor treatment did not show a statistically significant effect (ns).