The Rhine catchment in Switzerland has been transformed by a chain of hydroelectric power stations. We addressed the impact of fragmentation on the genetic structure of fish populations by focusing on the European chub (Squalius cephalus). This fish species is not stocked and copes well with altered habitats, enabling an assessment of the effects of fragmentation per se. Using microsatellites, ...

In northern Canada, lake chub (Cyprinidae: Couesius plumbeus) have colonized a variety of thermal springs that differ substantially from the ancestral environment in both mean temperature and thermal variation. To examine whether this environmental change is associated with differences in physiological traits, we compared the thermal breadth, capacity for acclimation of thermal tolerance, and m...

Total length (L(T)) and mass measurements of 28,596 specimens of European chub Leuciscus cephalus, collected from a variety of waterways across Italy, were used to compute standard mass (W(s)) equations by both empirical percentile (EmP) and regression line percentile (RLP) methods. The use of the EmP W(s) equation [log(10) W(s) = -4·79 + 2·68log(10) L(T) + 0·10(log(10) L(T))(2)] to compute rel...

The aim of this study was to compare, under controlled conditions, reproduction results of cultured and wild stock of the chub. Wild fish spawned only once a season whereas the cultured stock spawned at least two times. In the multiple-spawn stock, fewer fish spawned and the weight of produced oocytes was reduced compared to the single-spawn stock. Larvae obtained from the multi-spawn forms wer...

Invasive predators pose a critical threat to native taxa. Body size plays an important role in mediating the interactions of predator and prey. For piscivorous fishes, increased body can be accompanied by selection increasingly larger prey or may reflect mix small large Knowledge such helps determine how predation affects population vital rates. Here, we assessed predatory effects invasive Brow...

Abstract This study was carried out in April - June 2014 to determine absolute fecundity (F) of the chub mackerel (Scomber japonicus Houttuyn, 1782) Saros Bay (Aegean Sea, Turkey). The relations between and total length, weight age females were estimated as F=0.0318TL4.81, F=1573.9TW- 42858 F=109607A-136129, respectively. aims contribute reproductive biology S. by reporting first findings about...

Tissue samples from 1,117 fish of 25 species were collected from 1991 through 1996 at 13 locations along the River Elbe. The principal indicator species were perch (Perca fluviatilis) (n=118), chub (Leuciscus cephalus L.) (n=113) and roach (Rutilus rutilus) (n=138). Mercury (Hg) concentrations in muscle and liver were determined by atomic absorption spectrometry. The liver/muscle index in three...