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In this study we examined the ontogenic development of the digestive tract of Vimba bream (Vimba vimba, Family: Cyprinidae) during the first 60 days of life (hatching to 60 days after hatching [DAH]). Samples of developing Vimba bream were randomly selected at various stages of development: 1-8, 10, 15, 20, 25, 30, 40, 50, and 60 DAH. For the histological and histochemical studies on the development of the alimentary canal, tissue sections prepared from the sampled hatchlings were stained with hematoxylin-eosin and periodic acid-Schiff and observed under a light microscope. The histological structures of both the mouth and esophagus were fully developed at 5 and 7 DAH, respectively. Intestinal differentiation was observed at 2 DAH, while mucosal folds appeared on the intestinal bulb at 7 DAH. At 5 DAH, with the appearance of goblet cells in the epithelium of the mouth, pharynx, and esophagus, the larvae showed secretion activity in these organs. At 6 DAH, secretion was observed in the intestine; at this stage of development, the surface of the gastrointestinal tract was covered in a neutral mucous-like layer of polysaccharide. The histological observations indicate that the early development of the digestive tract in Vimba vimba enables larvae to efficiently ingest and digest exogenous feed very quickly after hatching. [ABSTRACT FROM AUTHOR]

Abstract: An attempt was made to assess the influence of major limiting factors on changes in the vimba population number in the Volgograd Reservoir. According to one hypothesis based on the accessibility of vimba spawning grounds, its population number in the reservoir is already close to the limit. According to another hypothesis considering limitations on the vimba population by food resources, an approximately 15-fold increase in the population number over at least two decades is possible. The above-mentioned hypotheses on the factors limiting increase in the vimba population number in the reservoir, provide different forecasts on the ultimate population number and time necessary for its achievement. The only possible way to verify these hypotheses is to carry out further research. [ABSTRACT FROM AUTHOR]

Until 1960s, vimba was found abundantly in Polish rivers and was an important species for the fishing industry. Overfishing, water pollution and dam constructions brought most of the vimba populations close to extinction. We analyzed the genetic variability of several remnant vimba populations in the Vistula and Oder river basins. The 305-bp fragment encompassing the 5′-end of the mtDNA control region was sequenced in a total of 202 wild specimens derived from six populations. Six different haplotypes were distinguished. The population of Barycz River was found to be the most polymorphic and was chosen as a source of breeding material for the vimba restitution program. In the years 2000-2008 fishes from this river were caught, spawned in captivity and released to the same river. The number of fishes returning to the Barycz River spawning grounds was monitored in the following years. In 2008, it was almost 70 times higher than the number of fishes recorded in 2003, when the lowest population size was observed. The haplotype and nucleotide diversities of the restored population were similar to those of the original population. [ABSTRACT FROM AUTHOR]