Identifying the relative importance of predation and resources in population dynamics has a long tradition in ecology, while interactions between them have been studied less intensively. In order to disentangle the effects of predation by juvenile fish, algal resource availability and their interactive effects on zooplankton population dynamics, we conducted an enclosure experiment where zoopla...

Species integrity can be challenged, and even eroded, if closely related species can hybridize and produce fertile offspring of comparable fitness to that of parental species. The maintenance of newly diverged or closely related species therefore hinges on the establishment and effectiveness of pre- and/or post-zygotic reproductive barriers. Ecological selection, including predation, is often p...

Abstract The aim of this study was to compare the susceptibility body deformities in juveniles 13 common European cypriniform fish, caused by intensive feeding with same commercial dry diet administered at 25°C according a similar schedule. final share individuals malformations differed considerably among species and 0.0-87.0%. Unaffected were only Barbus barbus (L.), Chondrostoma nasus Cyprinu...

This paper reports the results from mobile hydroacoustic surveys carried out between 1994 and 2018, to assess fish stocks in four impounded reaches, covering 19.8 km of River Thames, England. The data are complemented with electric fishing boom boat results, collected at same study reaches time periods. Hydroacoustic used inter-calibrated dual split-beam scientific echosounders, transducers bea...

The species composition of the ichthyofauna Samara River under influence man-made factors in Novomoskovsk district Dnipropetrovsk region is presented. environmental problem characterized, and on revealed. was analyzed based literature data, field ichthyological studies were also conducted to determine River. results technogenic modern realities have been obtained are summarized relation ichthyo...

Since the arrival of invasive quagga mussels Dreissena rostriformis bugensis in Lake Constance, significant changes zooplankton and benthic invertebrate community were observed. Five years later mussel has become dominating species community. Its effects on other components food web, especially those at higher trophic levels such as fish, remain unclear around world. To evaluate actual impact q...

Piscivory in cyprinids (Cyprinidae) is extremely rare. Specifically, common bream (Abramis brama) and common carp (Cyprinus carpio) are zooplanktivorous fish in deep lentic waters. Nevertheless, we observed predation by these two cyprinids under natural conditions in the Vír Reservoir, Czech Republic. We conducted diet analysis for cyprinids caught by trawling and gillnets and the large amount ...

Glochidia are the larval stage of freshwater unionid mussels that parasitize the fins and gill apparatus of fish. A total of 22 fish species were examined for the presence of glochidia whose distribution on individual hosts was studied on three common fish species, the roach Rutilus rutilus (L.), perch Percafluviatilis L. and bitterling Rhodeus sericeus (Pallas). Between 1997 and 1999, the fish...

Rhabdovirus was isolated from wild common bream Abramis brama during a disease outbreak with high mortality in Northern Ireland during May 1998. Rhabdovirus was also isolated at the same time from healthy farmed rainbow Oncorhynchus mykiss and brown trout Salmo trutta on the same stretch of river and 11 mo later from healthy wild bream and roach Rutilus rutilus in the same river system. Experim...