The Growth of Brown Trout (Salmo Trutta Linn.)

1946 ◽  
Vol 22 (3-4) ◽  
pp. 145-155
Author(s):  
MARGARET E. BROWN
Keyword(s):  
Differential Effect ◽  
Salmo Trutta ◽  
Specific Growth ◽  
Effect Of Temperature ◽  
Equal Weight ◽  
Different Temperatures ◽  
Brown Trout Salmo Trutta ◽  
Sigmoid Curve ◽  
Specific Growth Rates ◽  
Maintenance Requirements

1. Two-year-old trout were grown in controlled environmental conditions in water of different temperatures. 2. The specific growth rates of trout living at different constant temperatures and of those living in water of changing temperature were high between 7 and 9°C. and between 16 and 19°C., and were low above, between and below these temperatures. The existence of these two growth rate maxima may be explained by a differential effect of temperature on the amount of food eaten and the activity of the fish, the former being maximal between 10 and 19°C. and the latter between 10 and 12°C. The efficiency of utilization of the food was low when the temperature was low and also when the activity was high. 3. The maintenance requirements of trout of equal weight increased with increase in temperature. The relation followed a sigmoid curve, which may be explained by a differential effect of temperature on the basal metabolism and on the activity of the trout.

The Growth of Brown Trout (Salmo Trutta Linn.)

1951 ◽  
Vol 28 (4) ◽  
pp. 473-491
Author(s):  
MARGARET E. BROWN
Keyword(s):  
Salmo Trutta ◽  
Chemical Substance ◽  
Orange Pigment ◽  
Once Daily ◽  
Constant Rate ◽  
Different Temperatures ◽  
Brown Trout Salmo Trutta ◽  
Survival And Growth ◽  
Four Levels ◽  
Maintenance Requirements

Groups of 100 trout fry were grown in identical aquarium tanks at constant temperatures, with 12 hr. of illumination per day, constant rate of water flow, aeration and composition of the water. Two different temperatures, three different types of food and four levels of feeding were investigated. Individual lengths were recorded for the first 11 weeks after the beginning of feeding. The trout fry took live Tubifex worms eagerly and grew well up to a certain size, when they began to develop bleeding from the fins and dilation of cutaneous blood vessels and to die. It is suggested that Tubifex either lacks some chemical substance essential for trout survival or contains some substance which is accumulative poison. The trout fry which were fed with shrimp meal lost condition and showed poor survival and growth, suggesting that their diet lacked some necessary constituent. These fish developed orange pigment in their caudal and adipose fins; such orange pigment was not developed by fry fed with Tubifex or with liver. The trout fry which were fed with liver had the lowest mortality and showed the best growth, supporting the view that liver contains all the substances necessary for trout growth. Fry fed twice daily with liver showed less enthusiasm for their food than those fed once daily but the former grew slightly faster. Fry fed three or four times per week with liver gorged themselves whenever they were fed but grew at lower rates than those fed daily. Trout fry allowed to eat as much liver as they would once per week gorged themselves, but obtained less than their maintenance requirements and began to die of starvation after 4 weeks at 12.5° C. They were able to grow slowly when fed twice per week. Fry fed once or twice daily with liver grew larger than those thus fed with Tubifex, and the latter grew larger than fry fed daily with shrimpmeal. There were no significant differences in size which could be correlated with diet among fish fed less often than once daily. Trout fry fed daily at 10.5° C. grew more slowly than those fed daily at 12.5° C., but those fed less frequently showed no differences in growth rate which could be associated with temperature. Those fed with Tubifex at 10.5° C. showed a delay of 2 weeks in the onset of high mortality compared with those at 12.5° C.

The Growth of Brown trout (Salmo Trutta Linn.)

1946 ◽  
Vol 22 (3-4) ◽  
pp. 118-129
Author(s):  
MARGARET E. BROWN
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Growth Rates ◽  
Salmo Trutta ◽  
Specific Growth ◽  
Specific Rate ◽  
Size Hierarchy ◽  
Living Space ◽  
Brown Trout Salmo Trutta ◽  
Specific Growth Rates

1. Groups of trout fry of the same parentage were grown in environments where the following factors were controlled: temperature, amount and intensity of illumination, rate of water flow, aeration and chemical composition of the water, amount of living space and quality of food supply. They were allowed to eat as much as they would, and individual weights were recorded during the first 8 months after the beginning of feeding. 2. There was soon an increase in the range of individual weight in each group of fry, and thereafter the larger fry grew faster than smaller ones. When the larger fry were removed, the smaller ones grew at an increased specific rate, and when larger fry were added, the smaller ones grew more slowly. It is suggested that a ‘size hierarchy’ was established within each group, and an individual's specific growth rate depended on its position in the order of decreasing weight. 3. There was an optimum degree of crowding for maximum productivity. Compared with the fry in this group, the specific growth rates of individuals in larger, more crowded groups depended on the number of fish of larger size, while in smaller, less crowded groups, individuals grew at rates depending on the proportion of fish which were larger and smaller. 4. Alevin weight had little effect on the specific growth rates of fry. 5. There were differences between the growth histories of fry derived from alevins of the same weight and descended from the same father but different mothers (all of the same stock, age and size). 6. The specific growth rates decreased as the fry grew older, but there was no correlation between body weight and specific growth rate, except for the size hierarchy effect within each group. This effect had a greater influence on the size of individual fry than had either alevin weight or heredity.

RNA/DNA ratios in white muscle as estimates of growth in rainbow trout held at different temperatures

1990 ◽  
Vol 68 (7) ◽  
pp. 1494-1498 ◽  
Author(s):  
Moira M. Ferguson ◽  
Roy G. Danzmann
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
White Muscle ◽  
Specific Growth ◽  
Fish Size ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Different Temperatures ◽  
Specific Growth Rates ◽  
Rna And Dna

The concentrations of RNA, DNA, and protein in white muscle from 240 uniquely tagged rainbow trout (Oncorhynchus mykiss) held at three temperatures (5, 8 (control), and 11 °C) were measured. Both RNA and RNA/DNA ratios were better predictors of recent length- and weight-specific growth rates than they were of absolute fish size. Furthermore, RNA concentrations were better predictors of growth than RNA/DNA ratios. The strength of the regression between either RNA/DNA ratio or RNA and growth rate did not differ consistently among temperatures. Fish reared at warmer temperatures had lower concentrations of RNA for both a given growth rate and a given DNA concentration compared with cold-reared trout. Warm-reared fish also had lower concentrations of DNA and higher protein/DNA ratios than cold-reared trout when fish size was standardized. The concomitant decrease in both RNA and DNA concentrations resulted in marginally lower RNA/DNA ratios in warm-reared fish.

scholarly journals Effect of feeding Artemia Urmiana cysts on performance and survival of Caspian brown trout (Salmo trutta caspius) fish at the larva stage

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Reza Ebrahimi Khezr Abad ◽  
Masoud Farrokhrooz ◽  
Ali Nekuie Frad
Keyword(s):  
Brown Trout ◽  
Feed Intake ◽  
Salmo Trutta ◽  
Specific Growth ◽  
Caspian Brown Trout ◽  
Brown Trout Salmo Trutta ◽  
Different Levels ◽  
Effect Of Feeding ◽  
Salmo Trutta Caspius ◽  
Artemia Urmiana

This study was conducted to evaluate the effect of feeding different levels of Artemia Urmiana cysts on performance and survival of Caspian brown trout fish. The treatments included different levels (25, 50, 75 and 100 %) of Artemia Urmiana cysts to Caspian brown trout fish with an average weight of 120 ± 25 g in active phase of larva stage until the weight of one gram. Feed intake (FI), weight gain (WG), body weight (BW), feed conversion ratio (FCR), specific growth rate (SGR) of the treatments were determine and the survival percentage index was calculated based on the number of remaining larvae in the sites on the total number of larvae. The result of study showed that the higher feed intake was for 25 and the lower feed intake was for 50% of Artemia urmiana cysts treatments. Also the best specific growth rate and feed conversation ratio was related to the 25 % of Artemia Urmiana cysts groups (P≤0.05). Additionally the best survival index was for fish that fed by 75% and the worst survival index was for fish that fed by 100% of Artemia urmiana cysts. In conclusion we could demonstrated that feeding Artemia Urmiana cysts may have some beneficial effects on the performance and survival of Caspian brown trout (Salmo trutta caspius) fish at the larva stage.

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.

Effect of Temperature and Feeding Regime on the Specific Growth Rate of Sockeye Salmon Fry (Oncorhynchus nerka), with a Consideration of Size Effect

1973 ◽  
Vol 30 (8) ◽  
pp. 1191-1194 ◽  
Author(s):  
J. E. Shelbourn ◽  
J. R. Brett ◽  
S. Shirahata
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Sockeye Salmon ◽  
Specific Growth ◽  
Oncorhynchus Nerka ◽  
Effect Of Temperature ◽  
Salmon Fry ◽  
Wet Weight ◽  
Continuous Feeding ◽  
Specific Growth Rates

Specific growth rates were obtained for sockeye fry (Oncorhynchus nerka) acclimated to four temperatures and fed excess ration over a 36-day period, starting at an initial weight of 0.4 g. The rates were 2.2 (5 C), 5.1 (10 C), 6.5 (15 C), and 6.1 (20 C)% wet weight/day. Continuous feeding for 15 hr/day at 20 C produced a significantly greater growth rate than feeding to satiation three times daily (P < 0.05). The growth rates are compared to those obtained for larger sockeye, determined in earlier experiments.

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