Temperature-induced sex reversal is not responsible for sex-ratio distortions in grayling Thymallus thymallus or brown trout Salmo trutta.

Effects of chloramine-T exposure on oxidative stress biomarkers and liver biochemistry of rainbow trout, Oncorhynchus mykiss (Walbaum), brown trout, Salmo trutta (L.), and grayling, Thymallus thymallus (L.)

Oxidative stress, biochemical and enzymological biomarkers were compared among rainbow trout, Oncorhynchus mykiss (Walbaum), brown trout, Salmo trutta (L.), and grayling, Thymallus thymallus (L.) to determine the mechanisms of hepatotoxicity caused by chloramine-T bath treatment. The fish were exposed to chloramine-T at a concentration of 9 g m for 20 min three times daily every three days. The...

Effects of iron, aluminium, dissolved humic material and acidity on grayling (Thymallus thymallus) in laboratory exposures, and a comparison of sensitivity with brown trout (Salmo trutta)

Occurrence of intersex in wild freshwater fish in Slovenian rivers: a histological evaluation.

The aim of this preliminary research was to establish if there are intersex occurrences in wild freshwater fish in Slovenian rivers and streams. In the first study we evaluated all fish species of both sexes obtained from the river Ljubljanica from its source to mouth. In the second study we focused on the rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta m. fario) males from 30...

Vibrio cholerae non-O1/non-O139 infection in fish in the Czech Republic

Pathogenic Vibrio cholerae non-O1/non-O139 was isolated from the fry of the Cardinal tetra, Paracheirodon axelrodi and in adult Raphael catfish, Platydoras costatus kept in aquarium conditions. Further, an outbreak of vibriosis occurred in the wild populations of common nase, Chondrostoma nasus; chub, Squalius cephalus; gudgeon, Gobio gobio; stone loach, Barbatula barbatula; barbel, Barbus barb...

Mismatch between fishway operation and timing of fish movements: a risk for cascading effects in partial migration systems

Habitat fragmentation is a growing problem worldwide. Particularly in river systems, numerous dams and weirs hamper the movement of a wide variety of species. With the aim to preserve connectivity for fish, many barriers in river systems are equipped with fishways (also called fish passages or fish ladders). However, few fishways provide full connectivity. Here we hypothesized that restricted s...