Jumping is a common form of locomotion for many arboreal animals. Many species of the arboreal lizard genus Anolis occupy habitats in which they must jump to and from unsteady perches, e.g. narrow branches, vines, grass and leaves. Anoles therefore often use compliant perches that could alter jump performance. In this study we conducted a small survey of the compliance of perches used by the ar...

The trophic linkage between yellow perch Perca flavescens and two exotic prey items, alewife Alosa pseudoharengus and round goby Neogobius melanostomus, was investigated in the extreme southern area of Lake Michigan during the summer of 2002. Yellow perch 100mm total length, LT (n1⁄4 1293) exhibited size selective feeding, with 148 fish containing round gobies and 120 fish containing alewives. ...

The White Bass Morone chrysops is a popular sport fish that appears to be negatively affected by invasions of White Perch M. americana and often declines or disappears from invaded systems. In 2008, the first discovery of White Perch in Lake James, North Carolina, provided a rare opportunity to investigate trophic overlap between White Perch and a robust population of White Bass near the onset ...

Nile perch (Lates niloticus) suddenly invaded Lake Victoria between 1979 and 1987, 25 years after its introduction in the Ugandan side of the lake. Nile perch then replaced the native fish diversity and irreversibly altered the ecosystem and its role to lakeshore societies: it is now a prised export product that supports millions of livelihoods. The delay in the Nile perch boom led to a hunt fo...

Predation is thought to be one of the main structuring forces in animal communities. However, selective predation is often measured on isolated traits in response to a single predatory species, but only rarely are selective forces on several traits quantified or even compared between different predators naturally occurring in the same system. In the present study, we therefore measured behavior...

Due to the importance of young-of-the-year (YOY) perch in the peri-alpine regions where they are consumed, the microcystin (MC) contamination of YOY perch was analysed both in field (Lake Bourget, France) and experimentally using force-feeding protocols with pure MCs. In-situ, schools of YOY perch present in the epilimnion of the lake were never found in direct contact with the P. rubescens blo...

Acid soluble collagen (ASC) was extracted from the skins of young and adult Nile perch (Lates niloticus) using 0.5 M acetic acid and precipitation using 0.9 M NaCl. The ASC yields, on a dry weight basis, were 63.1 and 58.7%, respectively for young and adult fish skins. SDS PAGE showed the collagens to contain two alpha components (a1 and (2). ASC from Nile perch was found to contain more imino ...

So far, perch egg strands have been considered unpalatable biological material. However, we repeatedly found egg strands of European perch (Perca fluviatilis) in the diet of European catfish (Silurus glanis) caught by longlines in Milada and Most Lakes, Czech Republic. The finding proves that perch egg strands compose a standard food source for this large freshwater predatory fish. It extends t...

Polychlorinated biphenyls (PCBs) have been monitored in perch (Perca fluviatilis), pike (Esox lucius), and Arctic char (Salvelinus alpinus) in reference lakes since the late 1960s. Temporal trends and spatial patterns are currently monitored in nine and 32 lakes, respectively. Overall, PCB concentrations are decreasing. However, this is not consistent for all congeners across all lakes and spec...

1. Results for the copper and zinc contents ofeye tissues of perch, trout, and frogs are presented. The results of Leiner & Leiner (1944) for zinc in perch and trout are confirmed. 2. Most of the zinc, and half the copper, of the perch choroids is bound in non-ionic form to the pigment-protein fraction of the tissue. 3. The absorption spectra of pigment-protein suspensions from perch and frog e...