Gonadosomatic index (GSI) of female whitefish (Coregonus lavaretus) in Lake Constance

Human-induced changes in the reproductive traits of Lake Constance common whitefish (Coregonus lavaretus).

Size-selective fishery harvest leads to phenotypic changes in fish reproductive traits. When these changes represent an evolutionary response of a stock, they may have severe consequences for future stock dynamics and yields. In freshwater ecosystems, reproductive traits may also be affected by other human impacts such as changes in system productivity. The present study uses regression analysi...

The influence of eutrophication and population biomass on common whitefish (Coregonus lavaretus) growth : the Lake Constance example revisited

Accelerated growth of freshwater fish during anthropogenic eutrophication has been attributed almost exclusively to the increased nutrient content, while density-dependent effects have been largely neglected. We evaluated the relative importance of these factors by studying the growth of 43 consecutive year classes of common whitefish (Coregonus lavaretus) from Upper Lake Constance. This prealp...

Alizarin marking of whitefish, Coregonus lavaretus otoliths during egg incubation

Alizarin red S from 200 to 5000 mg L was used to mark the otoliths of whitefish embryos Coregonus lavaretus (L.) from 5 days after fertilization until shortly before hatching, to develop a method for evaluating the effect of stocking whitefish. Mark quality depended on developmental stage at the time of immersion. The best results were obtained when the otolith primordia had formed and had star...

Ecology of sympatric whitefish (Coregonus lavaretus (L.)) forms in a subarctic lake

This thesis concerns the ecology of sympatric whitefish (Coregonus lavaretus (L.)) forms in a subarctic lake, northern Finland. Despite of rather common occurrence of sympatric whitefish forms in the northern hemisphere, limited amount of information exist about their ecology and morphological divergence. Furthermore, whitefish form data is usually gathered in various different lakes and collec...

Long term anthropogenic impacts on the whitefish (Coregous lavaretus L.) stock of Lake Constance