In the early 80-ies of last century, there was a sharp decline in population Caspian beluga Russia. Its fishing prohibited, except for catching reproduction and scientific purposes. practice sturgeon breeding, method repeated use females males by obtaining sexual products vivo, as well growing breeders artificial conditions, has become widely put into practice. Against background an acute short...

the aim of this study was comparative study of the effects of two prebiotics, fructooligosaccharide (fos) and yeast based prebiotic (ybp), on intestinal microbiota of beluga (huso huso) juvenile. the study was done in a complete randomize design include feeding beluga with diet contain either 1 or 2% yeast based prebiotic or fructooligosaccharide as well as a control group (5 treatments in trip...

variation in growth, feed utilization and survival was assessed in sturgeon fingerlings of beluga fed different dietary lipid levels. all diets were iso-nitrogenous (protein = 45%) comprising 3.4-3.7 kcal digestible energy g-1. triplicate groups of 35 fingerling beluga with a mean initial wet weight of 2.14 ± 0.07 g (± sd) were fed with four experimental diets containing 6.7, 10.5, 14 and 17% c...

In this study, we evaluated concentrations of twelve essential and non-essential elements (As, Cd, Co, Cu, Pb, Mg, Mn, Hg, Mo, Se, Ag, and Zn) in tissues of bowhead (Balaena mysticetus) and beluga (Delphinapterus leucas) whales from arctic Alaska (USA) and northwestern Canada. Tissue samples were collected between 1983 and 1997, mostly in 1995-97. The essential elements are reported to develop ...

Social structure involving long-term associations with relatives should facilitate the learning of complex behaviours such as long-distance migration. In and around Hudson Bay (Canada), three stocks of beluga whales form a panmictic unit, but have different migratory behaviours associated with different summering areas. We analysed genetic variation at 13 microsatellite loci among 1524 belugas,...

Bisimulation proofs play a central role in programming languages in establishing rich properties such as contextual equivalence. They are also challenging to mechanize, since they require a combination of inductive and coinductive reasoning on open terms. In this paper we describe mechanizing the property that similarity in the call-by-name lambda calculus is a pre-congruence using Howe’s metho...

A behavioral response paradigm was used to measure masked underwater hearing thresholds in two bottlenose dolphins and one beluga whale before and after exposure to impulsive underwater sounds with waveforms resembling distant signatures of underwater explosions. An array of piezoelectric transducers was used to generate impulsive sounds with waveforms approximating those predicted from 5 or 50...

Beluga whale ( Delphinapterus leucas (Pallas, 1776)) movements, habitat use, and diving behaviour have been studied using satellite-linked transmitters for decades. The inaccessibility of Arctic subarctic habitats makes these instruments especially valuable beluga research. long-term effects that tags tag attachments on belugas, however, are not well known because resightings occur relatively i...