No abstract

Aquaculture as an agricultural activity in our country is capable ofproducing large amounts of different types and categories of fish. Climate andgeographic characteristics of our country, the terrain and development of agriculturalproduction as well as compliance with the principle of “sustainable development”,the position and importance of fishery in a multipurpose water utilization, mustdetermine the direction of development of the future trout production. The mostimportant type of fish grown in the trout fisheries in BiH is the rainbow trout,Oncorhynchus mykiss (Walbaum, 1792). In addition to the fact that growing thistype of fish is attractive to many producers, considering the high yield potential,it is also characterized by a significant level of tolerance to varying microambientconditions of the environment. Given the importance of fish production in Bosniaand Herzegovina, which is one of the rare branches of food sector that has fulfilledthe international standards and criteria and secured access to the markets of the EUcountries, it is necessary to establish optimal conditions to ensure high productivityof salmonid fisheries. Studying the reproductive cycles can provide very preciseand significant results of the overall condition of the entire organism during thisvery complex physiological process and of the overall population in the respectiveecosystem.

Inter-population variability in morphological traits and fecundity of Alburnus alburnus (Linnaeus, 1758) from Bosnia and Herzegovina was analysed in this study. The results of the analyses based on 21 standard measurements and six meristic characters have shown the highest variation between distance between pelvic (ventral) fins and anal aperture. Analysis of variance (ANOVA) indicate statistically significant differences between six populations. Differences among meristic characters have been tested by Multiple Comparisons Kruskal-Wallas. Obtained results indicate statistically significant difference among samples for number of branched rays for caudal fin (KA/Ca), lateral line scales (Le) and a number of gill rackers (Rac). Discriminant function analysis indicate characters that had the strongest effect on the geographical variation between A. alburnus samples from Bosnia and Herzegovina. Characters with the strongest discriminant power are: preanal distance, length of pectoral fin, length of the ventral (pelvic) fin, minimum body height, caudal fins branched rays, and pelvic fins branched rays.Values for weight of the gonads and gonadosomatic index (GSI) have not shown any statistically significant difference among observed bleak populations. Regression analysis has been used to estimate the relations between GSI and standard length, body, and gonads weight. The gonadosomatic index has shown positive, non substational, relationship to gonads weight.

In Bosnia and Herzegovina, several illegal waste dumps pose a significant threat to soil and water contamination. The aim of this study was to determine the levels of heavy metal contamination of soils and microbiological contamination of water near investigated landfills. The goal was to identify the harmful effects of illegal landfills on the environment and public health, as well as assessing the potential of contaminants to pollute soil and water resources. Using an Atomic Absorption Spectrometer, the amounts and distribution of four heavy metals (Cd, Co, Pb, and Cr) in soil at four illegal landfills in Central Bosnia were studied. Three water samples collected near the dumpsites studied were tested for microbes. Bacteriological analyses of water included determination of total mesophilic aerobic bacteria, aerobic heterotrophic bacteria, total coliform and fecal coliform bacteria and fecal enterococci. Quantitative results were analyzed using an analysis of variance and Tukey HSD post hoc test. Concentrations of Cd (4.96 mg/kg) and Pb (206.97 mg/kg) recorded in soil at particular sites were above the limits of maximum allowable concentration. Cr and Pb values in soil samples were relatively higher on average than that of Cd and Co. Enrichment factor and pollution load index indicated high concentration of heavy metals in soil, especially Cd. Based on these results, waste from illegal landfills may release considerable amounts of harmful metals and microbes into the environment.

The testes of fish are paired organs, of a variable shape in different species of fish. Their structure in the salmonid species is lobular. With the histological assays, we established that the lobes were separated by the connective tissue septa, which, given the intensity of spermatogenesis in the studied groups of fish (Salmo trutta m. Fario; Oncorhynchus mykiss) sporadically disappear, in fact, they break. In the space between the lobes there are also cross-sections of blood vessels with visible erythrocytes. During the spermatogenesis, in the interstitium there are clearly observable interstitial endocrine (Leydig) cells that excrete steroid hormones. The intensity of the spermatogenesis in the studied fish varies, which is concluded on the basis of the presence of the spermatogenesis cells. In nature, the reproductive cycle in fish is mostly based on an annual cycle, and that is why different stages of reproduction take place at a different temperature and during a different photoperiod. Hence, regardless of the same time period, the spawning time in November, different types of breeding, and finally salmon farming, point to the very important factors that influence reproduction - diet and microclimatic conditions.