The endocrine cells of Salmo trutta macrostigma stomach and pyloric caeca have been investigated using immunohistochemical techniques. 8 antisera were tested and 6 of them were detected in the endocrine cells serotonin, somatostatin, substance P, galanin, CCK and neuropeptide Y. These immunoreactive cells are described for the first time in the stomach and pyloric caeaca of Salmo trut...

Metapopulation dynamics over the course of an invasion are usually difficult to grasp because they require large and reliable data collection, often unavailable. The invasion of the fish-free freshwater ecosystems of the remote sub-Antarctic Kerguelen Islands following man-made introductions of brown trout (Salmo trutta) in the 1950's is an exception to this rule. Benefiting from a full long te...

Since fish form an important source of human food, a considerable amount of data is available concerning their distribution and size under natural conditions. This is especially true for the Salmonidae because of their popularity with sporting fishermen. With the development of commercial hatcheries, there has been a certain amount of experimental work concerning the effect of various factors o...

The success of invasive species is frequently attributed to phenotypic plasticity, which facilitates persistence in novel environments. Here we report on experimental tests to determine whether the intensity of cryptic coloration patterns in a global invader (brown trout, Salmo trutta) was primarily the result of plasticity or heritable variation. Juvenile F1 offspring were created through expe...

A technique for the hypophysectomy of the brown trout is described which might be applicable to other salmonids. Hypophysectomy produced a decrease in water turnover which was corrected by prolactin therapy. Hypophysectomy resulted in a decrease in the next flux of osmotic water. Both osmotic and diffusional water permeabilities were evenly decreased after hypophysectomy, such that the ratio of...

It has long been known that brown trout (Salmo trutta Linn.) grow to different sizes in different waters, and there has been much speculation concerning the factors determining these differences. Dahl (1918-19) suggested that the food supply and the degree of crowding were important; also that small, slowly growing trout were derived from smaller ova than those growing more rapidly. Southern (1...

  There is no available adequate information on the biology and genetics of the Caspian salmon (salmo truta Caspiu) living in the Caspian Sea with other species such as common carp families, sturgeons and etc., therefore we are interested in knowing whether selection for rapid growth rate in salmo trutta Caspius will potentially lead to correlated genetic response in body weight and length. The...

Reaction norms are a valuable tool in evolutionary biology. Lately, the probabilistic maturation reaction norm approach, describing probabilities of maturing at combinations of age and body size, has been much applied for testing whether phenotypic changes in exploited populations of fish are mainly plastic or involving an evolutionary component. However, due to typical field data limitations, ...

Subsidies of energy and material from the riparian zone have large impacts on recipient stream habitats. Human-induced changes, such as deforestation, may profoundly affect these pathways. However, the strength of individual factors on stream ecosystems is poorly understood since the factors involved often interact in complex ways. We isolated two of these factors, manipulating the flux of terr...

Exotic species present a great threat to native fish conservation; however, eradicating exotics is expensive and often impractical. Mechanical removal can be ineffective for eradication, but nonetheless may increase management effectiveness by identifying portions of a watershed that are strong sources of exotics. We used mechanical removal to understand processes driving exotic brown trout (Sa...