Differences in Brown Trout (Salmo trutta) Production among Contiguous Sections of an Entire Stream

1989 ◽  
Vol 46 (2) ◽  
pp. 203-213 ◽  
Author(s):  
Raymond M. Newman ◽  
Thomas F. Waters
Keyword(s):  
Growth Rate ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Standing Stock ◽  
Production Factors ◽  
Habitat Differences ◽  
Brown Trout Salmo Trutta ◽  
Standing Stocks ◽  
Relative Differences ◽  
Production Dynamics

Production dynamics of a wild brown trout (Salmo trutta) population were examined for 3 yr in each of eight contiguous 305-m-long sections that constituted the entire length of South Branch Creek, a limestone stream in southeastern Minnesota. Total trout densities increased from about 1600/ha in 1980 to 2300/ha in 1982. There were large and significant differences in density among sections; relative differences among sections, however, were nearly constant over the 3 yr. Mean annual standing stock and production increased over the 3 yr from about 90 and 100 kg/ha, respectively, in 1980 to 150 and 174 kg/ha, respectively, in 1982. Standing stock and production also differed significantly among sections, but relative differences among sections were fairly constant over the 3 yr. The most productive sections had standing stocks and production rates that were 1.5–2 times higher than the least productive sections. Year strongly influenced growth rate, with growth in 1982 almost double that in 1981, but growth rates did not differ significantly among sections. Habitat differences among sections appeared to regulate density, size, standing stock, and production. Factors that affected the entire stream influenced recruitment and growth.

Longevity, Body Size, and Growth in Anadromous Brown Trout (Salmo trutta)

1991 ◽  
Vol 48 (10) ◽  
pp. 1838-1845 ◽  
Author(s):  
Bror Jonsson ◽  
Jan Henning L'Abée-Lund ◽  
Tor G. Heggberget ◽  
Arne J. Jensen ◽  
Bjørn O. Johnsen ◽  
...  
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Water Temperature ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Ambient Water ◽  
Ambient Water Temperature ◽  
Brown Trout Salmo Trutta ◽  
Interpopulation Variation ◽  
Temperature And Growth

Longevity in 25 populations of anadromous brown trout (Salmo trutta) showed a significant trend with increasing life span at latitudes of 58–70°N in Norway, with the largest change from 58 to 60°N. Moreover, longevity was negatively correlated with temperature and growth rate in freshwater and at sea. Body size was negatively correlated with water temperature and growth rate in freshwater, but not with latitude or water temperature and growth rate at sea. Thus, conditions influencing development and metabolic rates in fresh water seem more important than conditions in the sea in determining variation in longevity and body size of anadromous brown trout. Our results support the hypothesis that interpopulation variation in longevity and body size is influenced by rate of metabolism, chiefly influenced by ambient water temperature.

Effect of Feeding Brown Trout (Salmo trutta) a Diet Pelleted in Dry and Moist Forms

1974 ◽  
Vol 31 (11) ◽  
pp. 1824-1826 ◽  
Author(s):  
Hugh A. Poston
Keyword(s):  
Growth Rate ◽  
Body Composition ◽  
Energy Density ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Dry Matter ◽  
High Moisture ◽  
Brown Trout Salmo Trutta ◽  
Juvenile Brown Trout ◽  
Effect Of Feeding

Growth rate, body composition, and intake of either dry matter or energy did not differ significantly (P > 0.05) between two groups of juvenile brown trout (Salmo trutta) fed either a low- or high-moisture semipurified diet at different rates to compensate for a diet energy density gradient. Feed/gain efficiency, on an as-fed basis, was significantly greater (P < 0.01) in fish fed the low-moisture diet, but did not differ (P > 0.05) when compared on the basis of dry matter or energy intake.

Comparison of Actual and Potential Growth Rates of Brown Trout (Salmo trutta) in Natural Streams Based on Bioenergetic Models

1989 ◽  
Vol 46 (6) ◽  
pp. 1067-1076 ◽  
Author(s):  
Richard J. Preall ◽  
Neil H. Ringler
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Specific Growth ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Dominant Feature ◽  
Natural Streams ◽  
Brown Trout Salmo Trutta

A ratio of specific growth rate to predicted maximum growth rate was employed as an ecological growth coefficient (EGC) in identifying major determinants of growth for brown trout, Salmo trutta, in natural streams. The coefficient may be more useful than specific growth rate when comparing trout populations from streams having diverse characteristics, since it accounts for the quantitative effects of stream temperature and mean trout weight. The maximum growth rate was generated by translating Elliott's bioenergetic equations into computer models applicable to fish weighing 5–300 g and to stream temperatures of 3.8–21.7 °C. EQMAX is the simpler model and generates only maximum growth rate. TROUT estimates the maximum ration size, maximum growth rate, and a variety of bioenergetic parameters. The EGC for Age I + trout ranged from 60 to 90% in three central New York streams. A relatively low EGC (30–60%) observed for Age II + trout in one stream may have been due to the inefficiency of feeding on small invertebrates. Temperature appears to be a dominant feature governing trout growth in streams. The bioenergetic models may provide useful predictions of the effects of foraging on prey communities by brown trout.

Density-dependent effects of prior residence and behavioural strategy on growth of stocked brown trout (Salmo trutta)

2004 ◽  
Vol 82 (10) ◽  
pp. 1638-1646 ◽  
Author(s):  
Eva Brännäs ◽  
Sara Jonsson ◽  
Kurt Brännäs
Keyword(s):  
Growth Rate ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Lower Growth ◽  
Density Dependent ◽  
Behavioural Strategy ◽  
Behavioural Factor ◽  
Brown Trout Salmo Trutta ◽  
Prior Residency ◽  
Effect On Growth

When animals face temporally periods of strong intraspecific competition, prior residency, available resources, and their competitive abilities in terms of size and behavioural strategy affect their chances of survival. Density, individual size, and behavioural strategy had the strongest effect on growth. The mean growth rate of both resident and intruding brown trout (Salmo trutta L., 1758) decreased with increasing density, and the largest individuals were the most successful ones independently of the density of prior residency. An aggressive behavioural factor was beneficial at the lowest and intermediate densities, whereas a nonaggressive behavioural factor was beneficial at higher densities. Prior residency had no overall significant effect on growth, as the effect was highly density-dependent. The difference in growth rate between introduced and resident individuals was significant only at high density and low food abundance per individual. The intruders had a significantly lower growth rate at high densities and fewer individuals had a high growth rate. These results suggest that stocking fish at densities exceeding the carrying capacity of the habitat results in fewer individuals that are able to compete for resources than if fewer individuals were stocked. Brood stock can then be used in a more efficient way.

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