Egg drift from the nest is clearly an important cause of mortality in lithophilic species, but the effect of substrate composition on this process has been overlooked. Here, we investigated the role of substrate on the spawning preference and egg retention of river lamprey ( Lampetra fluviatilis ) during a whole breeding season in a two‐option experimental setting. Despite no initial preference, the lamprey eventually favoured...

Nest building relates to reproductive effort, sexual selection, intersexual conflict and cooperation and may be linked to individual phenotype and interindividual interactions. In particular, larger individuals having more energy reserves are expected to build more, larger nests, without having to trade intrasexual competition for cooperative nest building. Capture–mark–recapture and nest survey of sea lamprey ( Petromyzon mar...

We assessed the effects of sexual maturity on space use in Atlantic salmon ( Salmo salar ) parr as facultative early maturation enables us to work on individuals belonging to the same cohort. We monitored the space use of 40 1‐year‐old males in natura throughout a breeding season. First, mature individuals covered longer distances (absolute and upstream) and located within broader home ranges than immature parr. Second, sexual...

Electrofishing in streams of low water conductivity has technical limitations leading to the widespread use of poison fishing. In theory, provided a high enough voltage gradient can be created in water, electrofishing should be possible in all but the lowest of conductivities (