Introduced and allopatric populations of brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss were sampled in Slovenia for stable isotope analysis to assess dietary niche shifts through ontogeny and estimate the propensity for cannibalism. Both S. trutta and O. mykiss are cannibals, with higher average relative contribution of conspecific assimilated energy for S. trutta (27·9%) compared with O. mykiss (7·7%). The sm...

A simple approach is proposed to fit a body growth model for the European eel Anguilla anguilla to data‐poor case studies. The model is a modified von Bertalanffy curve allowing for delayed sex determination and sexual dimorphism. The proposed procedure provides preliminary estimates of model parameters on the basis of average age and body length of silver eels.

Total length ( L T ) (range 24–1000 mm; mean ± s.e . = 170·21 ± 0·36 mm) and mass ( W ) (range 0·10–9590 g; mean ± s.e . = 76·03 ± 0·87 g) of 36 460 specimens of marble trout Salmo marmoratus were used to compute a standard mass ( W s ) equation for this species by means of the empirical percentile (EmP) method. The EmP W s equation calculated was: log 10 W s = −5·208 + 3·202 log 10 L T − 0·046 (log 10 L T ) 2 ( L T range 90–5...

Maturation rates in three European eel Anguilla anguilla populations increased from September to October and were slightly lower in fresh water than in brackish waters. Average and variance of total length at maturation were larger in females than males.

Body growth parameters, age and total length at sex differentiation were compared in three European eel Anguilla anguilla populations from Mediterranean sites with different salinity. Whilst body growth was faster in brackish than in freshwater environments, the present analysis shows that body size at sex differentiation might be a physiological invariant.

Age and total length ( L T ) data from a 11 year monitoring of the Anguilla anguilla eel population of the Camargue lagoons (Rhône delta, southern France) were collected for glass, yellow and silver eels. Three distinct models were calibrated to describe the growth process of undifferentiated eels, females and males, respectively. Uncertainty of parameter estimates was evaluated by bootstrapping. Females were characterized by...

Populations of the marble trout ( Salmo marmoratus ) have declined critically due to introgression by brown trout ( Salmo trutta ) strains. In order to define strategies for long‐term conservation, we examined the genetic structure of the 8 known pure populations using 15 microsatellite loci. The analyses reveal extraordinarily strong genetic differentiation among populations separated by