In current study, protein hydrolysates were produced using microbial proteases of Alcalase, Protamex and Flavourzyme from by-products (head, skin and viscera) of Alosa (Alosa caspia), a major Clupeonella species in the Caspian Sea. The results indicated that the protein hydrolysate from Alcalase, had the highest protein content (78.91%), protein recovery (80.42%) and degree of hydrolysis (21.06...

The frequency range of hearing in fishes and frogs historically has been thought to be confined to relatively low frequencies in comparison to mammals (Hawkins, 1981; Fay, 1988). The fishes with the greatest sensitivity and frequency bandwidth, such as the otophysans, a group of species that have a mechanical coupling between the swim bladder and inner ear, have upper frequency sensitivities be...

Migrating fish traversing velocity barriers are often forced to swim at speeds greater than their maximum sustained speed (U(ms)). Failure to select an appropriate swim speed under these conditions can prevent fish from successfully negotiating otherwise passable barriers. I propose a new model of a distance-maximizing strategy for fishes traversing velocity barriers, derived from the relations...

Historical aerial applications of the insecticide Matacil 1.8D provide an opportunity to look for potential effects of the endocrine disrupting compound 4-nonylphenol (4-NP) on Atlantic salmon (Salmo salar) populations. Matacil 1.8D contained the carbamate insecticide aminocarb, with 4-NP as primary solvent. Between 1975 and 1985 Matacil 1.8D was applied to forests in Atlantic Canada to control...

Alewife, Alosa pseudoharengus, populations occur in two discrete life-history variants, an anadromous form and a landlocked (freshwater resident) form. Landlocked populations display a consistent pattern of life-history divergence from anadromous populations, including earlier age at maturity, smaller adult body size, and reduced fecundity. In Connecticut (USA), dams constructed on coastal stre...

Cordylophora caspia, a colonial hydrozoan native to the Ponto-Caspian region, has become a common invader of both fresh and brackish water ecosystems of North America and Europe. We describe 11 polymorphic microsatellite loci for this species. Preliminary analyses indicate that population substructure may contribute to departures from Hardy-Weinberg equilibrium. In addition, new loci failed to ...

Diadromous species act as nutrient vectors between their marine and freshwater habitats. Few valuations of this regulating service exist none at the scale distribution ranges. This large-scale approach seems particularly relevant for moving exchanging individuals across borders territories these populations may strongly depend upon each other in terms population viability provision ecosystem se...