The introduction of fish into mountain lakes typically leads to profound ecological changes within the food web, but its consequences depend on the dietary preferences of fish and on the resistance ...of prey organisms against predation. Here we used stable isotopes and fatty acid analyses in combination with the traditional stomach content analysis to examine the diet of an allopatric population of Salmo trutta, which has originally been stocked during the Middle Ages in an alpine lake, and to identify what components of the food web are more affected. The results from stable isotopes and fatty acids indicated that planktonic and benthic food sources, in particular chironomids larvae, were the most important prey items all year round. Airborne terrestrial insects made most of the stomach content during the ice-free period, but their stable isotope and fatty acids values did not match up with those in fish, suggesting a minor role for fish nutrition. Copepods were relevant as fish diet only during the ice-covered period. In contrast to the stable isotope values of the fish muscle tissue, those of the liver, which reflect potentially short-term changes in diet, were significantly different between the ice-covered and ice-free period. Fatty acid analysis revealed that polyunsaturated fatty acids contents of chironomids, copepods, and chydorids contributed similarly to fish diet. Overall, our results suggest that the introduction of this fish species has decreased the lake-to-land resource transfer by reducing the abundance of emerging midges and that the population is food-limited as indicated by its low condition factor. This field study eventually acts as a reference for possible future reintroduction efforts, as this population is one of few existing in Europe with pure Danubian origin.
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•A Salmo trutta population originally stocked during the Middle Ages in an alpine lake has established permanently.•Benthic chironomids larvae were the most important prey items all year round.•Stable isotope values of muscle and liver depicted different dynamics.•Introduction of this fish species has probably largely decreased the lake-to-land resource transfer.
Consumer preferences regarding the various species of fish or aquatic organisms are highly variable. The criteria by which they orient are represented by: the price, organoleptic characteristics, ...healing and nutritional properties of meat. Today it is known that a high consumption of fish meat has a beneficial role in human health. Moreover, statistics indicates a high level of life expectancy in countries with tradition in terms of fish consumption, e.g. North-European and Asian countries. Statistics shows a high consumption of ocean fish and different species of salmonid family. The culture and intensive fish farming represents an alternative to the requirements of the fish market. The salmonids farmers focus their efforts to obtain high yields of high quality, in conditions of maximum economic efficiency. In Romania, the predominant specie encountered in salmonis farms is rainbow trout (Oncorhynchus mykiss). It is successfully reared because of its plasticity and resistance to changes in environmental conditions and disease, and efficient feed-conversion. For restocking mountain water with biological material, some trout farms operate successfully brown trout (Salmo trutta fario), a less effective specie for meat production, due to slow growth and development and low resistance to changing environmental factors. Profitability of fish production depends on the propagation processes, fish growth and developments, and supplying optimal environmental conditions for enhancement of the biological potential. The artificial reproduction of salmonids, involves several technological operations for achieving outstanding results on fisheries production. Of these operations, critical is the selection and improvement of breeding.
We present a genome assembly from an individual female
Salmo trutta
(the brown trout; Chordata; Actinopteri; Salmoniformes; Salmonidae). The genome sequence is 2.37 gigabases in span. The majority of ...the assembly is scaffolded into 40 chromosomal pseudomolecules. Gene annotation of this assembly on Ensembl has identified 43,935 protein coding genes.
Brown trout is a common type of fish grown for consumption in open and flowing fish ponds on the rivers of Bosnia and Herzegovina. We conducted this study during three seasons (spring, summer and ...autumn) to obtain a complete picture of the morphological and histological characteristics of selected trout tissues. The physicochemical characteristics of the water from the Pliva River near Pljeva and the fish pond where intensive breeding of trout is carried out were analyzed. These analyses have shown that there are no major deviations in water quality and that the water in the pond is of excellent quality. A total of 90 trout were harvested during all three seasons and their morphometric characteristics were determined by analyzing ten parameters. After the dissection of all individuals, histological and stereological analysis was performed to compare the tissues of the liver, stomach, gills and muscles. These analyses showed significant differences in the histoarchitecture of selected trout tissues from the pond compared to the river. Liver tissue had altered hepatocyte shape and presence of adipocytes; stomach tissue had stronger mucosa and weaker muscle layer; gill tissue had lower respiratory lamellae; while muscle tissue had a significant presence of adipose tissue in brown trout living in the fish pond compared to those in the river. All these changes are due to the quality of commercial feed and the inability to move freely.
The physiological causes of intraspecific differences in fitness components such as growth rate are currently a source of debate. It has been suggested that differences in energy metabolism may drive ...variation in growth, but it remains unclear whether covariation between growth rates and energy metabolism is: (i) a result of certain individuals acquiring and consequently allocating more resources to growth, and/or is (ii) determined by variation in the efficiency with which those resources are transformed into growth. Studies of individually housed animals under standardized nutritional conditions can help shed light on this debate. Here we quantify individual variation in metabolic efficiency in terms of the amount of adenosine triphosphate (ATP) generated per molecule of oxygen consumed by liver and muscle mitochondria and examine its effects, both on the rate of protein synthesis within these tissues and on the rate of whole-body growth of individually fed juvenile brown trout (Salmo trutta) receiving either a high or low food ration. As expected, fish on the high ration on average gained more in body mass and protein content than those maintained on the low ration. Yet, growth performance varied more than 10-fold among individuals on the same ration, resulting in some fish on low rations growing faster than others on the high ration. This variation in growth for a given ration was related to individual differences in mitochondrial properties: a high whole-body growth performance was associated with high mitochondrial efficiency of ATP production in the liver. Our results show for the first time, to our knowledge, that among-individual variation in the efficiency with which substrates are converted into ATP can help explain marked variation in growth performance, independent of food intake. This study highlights the existence of inter-individual differences in mitochondrial efficiency and its potential importance in explaining intraspecific variation in whole-animal performance.
Brown trout (Salmo trutta) is composed of numerous geographical forms in the wild and a multitude of stocks reared in hatcheries. Practices impacting this species are domestication and fish farming. ...Thousands of hatcheries are producing domestic trout which are frequently released in the wild without real knowledge of the origin and genetic composition of the strains and of the receiving populations. The present study contains an analysis of the genetic structure (using twelve microsatellites) of 26 hatchery strains from Europe (Sweden, Poland, Czech Republic, Slovakia, Hungary, France, Italy and Spain) and one from North America (Minnesota). Several new observations improved our knowledge on this domestic part of S. trutta. First, a cross-border commercial strain of the North Atlantic lineage occupies most of European hatcheries and the American one, as a probable consequence of intensive exchanges of broodstock materials over time. In addition to the common Europe-wide commercial Atlantic strain, local strains stemming from domesticated regional wild fish also occur. Second, the level of genetic polymorphism of most hatchery strains is high to very high, likely reflecting genetic admixture counteracting expected losses of diversity through random genetic drift and domestication. This study emphasizes the value of identifying the genetic composition of hatchery stocks used for releases. It further stresses the need for caution when stocking a common stock across the whole geographical range of a species, with risks for reducing the intraspecific genetic diversity and local adaptation.
•Brown trout (Salmo trutta) is one of the most manipulated freshwater fish for angling. The main manipulation was and is domestication of thousands of strains all around the world, but mainly in Europe, main origin of the species. Theses domestic fish are released in the wild.•Trout management does not include genetic analyses and managers stock genetically unknown strains in genetically unknown river populations. The negative effect of such a practice is documented in the scientific literature.•The aim of the present paper is to analyze a maximum of hatchery strains (here 26) in a maximum of European countries (here 8 + USA) to understand the genetic and geographic structure of the domestic part of Salmo trutta.•One of the main result is the detection of an international strain (called ComATL) distributed in all countries and threatening the global brown trout genetic diversity.
The above article from the Ecology of Freshwater Fish, published online on 20 December 2019 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/abs/10.1111/eff.12527), has been retracted by ...agreement between the journal Editor‐in‐Chief; the symposium editor, Phaedra Budy; and the author, Troy Zorn. The retraction has been made due to a mistake in the classification (accessible vs. landlocked) of one of the survey locations in Table 1, which affected the accuracy of other analyses in the article.
Ceftriaxone (CTX) is a third-generation cephalosporin that has proven to be effective in the treatment of infections caused by a wide range of gram-positive and gram-negative microorganisms. This ...study aimed to determine the plasma and muscle pharmacokinetics of CTX after its administration via the intravenous (IV) and intramuscular (IM) routes to brown trout (Salmo trutta fario) at temperatures of 10 °C–13 °C. In total, 140 healthy brown trout (body weight, 245 ± 38 g) were used. The brown trout received single IV and IM injections of CTX at 25 mg/kg. The IV doses were injected into the caudal vein, whereas the IM doses were injected into the right epaxial muscles. The plasma and muscle tissue concentrations of CTX were measured using high-performance liquid chromatography. Pharmacokinetic parameters were calculated using noncompartmental methods. Following the IV administration of CTX, the elimination half-life (t1/2ʎz), volume of distribution at steady state, total body clearance, and area under the concentration–time curve (AUC0–72) in plasma were 5.83 h, 0.09 L/kg, 0.02 L/h/kg, and 1079.46 h*μg/mL, respectively. After the IM administration of CTX, plasma t1/2ʎz, peak plasma concentration (Cmax), time to reach Cmax, and bioavailability were 22.78 h, 87.92 μg/mL, 0.5 h, and 27.19%, respectively. The AUCMuscle/AUCPlasma ratio following the IV administration was 0.02 and that following the IM administration was 0.04. CTX exhibited low bioavailability and prolonged t1/2ʎz after the IM administration. The prolonged t1/2ʎz of CTX could thus be beneficial in brown trout. Nevertheless, future studies that aim to determine the clinical efficacy and pharmacokinetics after repeated administration of CTX are warranted.
•Plasma and muscle pharmacokinetics of ceftriaxone were determined in brown trout (Salmo trutta fario)•The administration route changed significantly plasma and muscle pharmacokinetics•Ceftriaxone was able to penetrate poor the muscle tissue•Ceftriaxone exhibited a prolonged elimination half-life and a low absolute bioavailability
Caspian brown trout is one of the valuable, commercial, anadromous, and endemic species of the Caspian Sea, which has noteworthy the attention of many scientists. This study was carried out using ...Caspian brown trout fingerlings (n = 300) with an initial average weight of 42 g for two months. In this study, different amounts of carrot powder (total carotenoids) were added to fish diets including a control group and five treatments i.e. 0 (control), 50 (T1), 100 (T2), 150 (T3), 200 (T4) and 250 mg/kg (T5). The effects of different amounts of carotenoids were investigated on some blood parameters of fingerlings, including lysozyme, alkaline phosphatase, alanine aminotransferase, aminotransferase, glucose, total protein, and cortisol. According to the results, significant differences (p<0.05) were observed in the amounts of serum lysozyme between different treatments. Treatment 2 by an average of 51 ± 3.61 U/mL and control group by 40.67 ± 2.52 U/mL exhibited the highest and lowest levels of the enzyme, respectively. Based on the results, a significant difference (p<0.05) was observed between different levels of cortisol in the treatments, so that the highest and lowest cortisol levels in the control group and treatment 2 with 50 ± 7 and 26.67 ± 4.04 (ng/mL) was observed. In general, based on the results of this study, it was found that different levels of carotenoids in the diet of salmon brown trout can display a significant effect (p<0.05) on blood indices.
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