Comparative Agonistic and Feeding Behavior of Hatchery-Reared and Wild Salmon in Aquaria

1968 ◽  
Vol 25 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Owen C. Fenderson ◽  
W. Harry Everhart ◽  
Kenneth M. Muth

When hatchery-reared and wild landlocked Atlantic salmon (Salmo salar) parr of the same age and size were permitted to compete for social dominance and for food in aquaria, twice as many hatchery salmon attained dominance as wild salmon. Dominant hatchery salmon also showed a higher intensity of aggressiveness than dominant wild salmon, displaying a higher and more variable mean nipping rate. Socially dominant salmon ate more food per fish than subordinates, but there were no statistically significant differences in feeding rate between dominant hatchery and dominant wild salmon, or between subordinate hatchery and subordinate wild salmon.Hatchery salmon displayed lower feeding rates than wild salmon when they were held in separate compartments of an aquarium and compared at three temperatures. This difference in feeding rate probably was not a reflection of differences in adaptation to temperature or food preference, but, rather, was the result of interference with feeding caused by the more intense social interaction among hatchery fish.It is suggested that high levels of aggressiveness may contribute to mortalities of hatchery-reared salmon planted in streams because of loss of feeding time, excessive use of energy, and increased exposure to predators.

2006 ◽  
Vol 63 (7) ◽  
pp. 1218-1223 ◽  
Author(s):  
Frederick G. Whoriskey ◽  
Paul Brooking ◽  
Gino Doucette ◽  
Stephen Tinker ◽  
Jonathan W. Carr

Abstract We sonically tagged and released farmed Atlantic salmon (Salmo salar) from a cage site in Cobscook Bay, Maine, USA. The fish were released in January (n = 75) and in April and May (n = 198) 2004 to study their movement patterns and survival and to assess the possibility of recapturing them. Inshore and offshore waters in this region are subject to intense tidal currents. Tagged salmon dispersed >1 km from the cage site within a few hours of their release. Mortality was high within Cobscook Bay and the surrounding coastal region (56% of the winter (January) releases; 84% of the spring (March) releases), probably the result of seal predation. Most surviving fish exited the coastal zone and entered the Bay of Fundy along the routes of the dominant tidal currents, passing through Canadian waters. No tagged fish were detected during the wild salmon spawning season in autumn 2004 in any of the 43 monitored salmon rivers draining into the Bay of Fundy, or during 2005 either in the Magaguadavic River, the site of the hatchery in which the fish were reared to the smolt stage, or by a limited coastal receiver array.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 233-234
Author(s):  
David N Kelly ◽  
Roy D Sleator ◽  
Craig P Murphy ◽  
Stephen B Conroy ◽  
Donagh P Berry

Abstract To the best of our knowledge, the genetic variability in feeding behavior, as well as relationships with performance and feed efficiency, has not been investigated in a cattle population of greater than 1,500 animals. Our objective was to quantify the genetic parameters of several feeding behavior traits, and their genetic associations with both performance and feed efficiency traits, in crossbred growing cattle. Feed intake and live-weight data were available on 6,088 bulls, steers and heifers; of these, 4,672 cattle had backfat and muscle ultrasound data, and 1,548 steers and heifers had feeding behavior data. Genetic (co)variance parameters were estimated using animal linear mixed models; fixed effects included test group, heterosis, recombination loss, dam parity, age in months at the end of test, and the two-way interaction between age in months at the end of test and sex. Heritability was estimated to be 0.51 (0.097), 0.61 (0.100), 0.44 (0.093), 0.48 (0.094), and 0.47 (0.095) for feed events per day, feeding time per day, feeding rate, feed event duration, and energy intake per feed event, respectively. Coefficients of genetic variation ranged from 0.11 (feeding time per day) to 0.22 (feed event duration). Genetically heavier cattle with a higher energy intake per day, and faster growth rate, had a faster feeding rate and a greater energy intake per feed event. Genetic correlations between feeding behavior and feed efficiency were generally not different from zero, however, there was a genetic correlation of 0.36 (0.11) between feeding time per day and residual energy intake. Significant heritable and exploitable genetic variation exists in several feeding behavior traits in crossbred growing cattle which are also correlated with several performance traits. As some feeding behavior traits may be relatively less resource intensive to measure, they could be useful as predictor traits in beef cattle genetic evaluations.


1969 ◽  
Vol 26 (9) ◽  
pp. 2535-2537 ◽  
Author(s):  
J. H. C. Pippy

Bacterial kidney disease was presumptively identified in each of 25 hatchery-reared juvenile salmon (Salmo salar) but in only 2 of 235 wild juveniles in the Margaree River system. Apparently spread of disease from the hatchery to wild salmon in the river is very gradual.


1970 ◽  
Vol 27 (9) ◽  
pp. 1617-1625 ◽  
Author(s):  
Dag Møller

Three main patterns of transferrins, made up of two molecular types, were found by starch–agar electrophoresis in plasma of hatchery and wild Atlantic salmon (Salmo salar).Distributions of the observed patterns from progenies of three hatchery matings agreed with expected Mendelian distributions in offspring of known parentage, implying that the bands have their origin in two codominant alleles. In nearly all samples of the wild salmon the genetic basis of transferrin variation was demonstrated by nonsignificant differences between observed and expected distributions when the Hardy–Weinberg formula was applied.Frequencies of the TfA allele differed in samples from different rivers and within the same river; the Atlantic salmon forms genetically different populations. Interchange of stocks probably influenced the values of the different gene frequencies found.


1998 ◽  
Vol 55 (2) ◽  
pp. 507-514 ◽  
Author(s):  
Arnulf Soleng ◽  
Tor A Bakke ◽  
Lars P Hansen

Population growth of Gyrodactylus salaris increased exponentially on Atlantic salmon (Salmo salar) smolts in laboratory experiments conducted at 12.0°C. Furthermore, G. salaris was transmitted successfully from salmon smolt to parr at 0.0, 7.5, 10.0, and 20.0%° salinity and reproduced in fresh water after direct transfer from 7.5%° (16 days), 20.0%° (4 and 8 h), and 33.0%° (5, 15, and 30 min). No G. salaris were observed on salmon parr exposed to 33.0%° for 60 min. The prevalence of G. salaris on wild salmon smolts caught approximately 25 km from the river mouth in the Drammensfjord (surface salinity 2.0-3.5%°) was 71.2% compared with 88.0% on those from the neighbouring River Lierelva. Adult wild salmon caught as prespawners, spawners, and postspawners (kelts) in the River Drammenselva were infected with G. salaris. The prevalence and abundance increased from autumn to spring, in contrast with earlier studies on salmon parr, demonstrating the possible importance of adult salmon as reservoirs for G. salaris during winter. The results support the hypothesis of brackish water dispersal of G. salaris by infected salmonids migrating in estuaries and fjords. The use of salt as a disinfectant against G. salaris in hatcheries, and the stocking of possibly infected fish into brackish and seawater, should also be reexamined.


1987 ◽  
Vol 44 (5) ◽  
pp. 1079-1082 ◽  
Author(s):  
Per Johan Jakobsen ◽  
Geir Helge Johnsen ◽  
Jens Christian Holm

Fishes hunting by sight are known to pay a cost of confusion when faced with high densities of uniform food particles. Factors such as swarm size, density, and visual uniformity increase confusion. Therefore, it may be profitable in pisciculture to introduce food particles in low densities or to reduce the uniformity and density of each type of feed pellet. This was tested by feeding Atlantic salmon parr (Salmo salar) brown pellets, yellow pellets, or a mixed diet. Mean growth rates were significantly higher for those fish fed a mixed diet. Of the smaller fish in all groups, those in the mixed diet group showed the highest weight/length ratio. We suggest that small individuals have to pay more attention to conspecifics than do large ones, and thus tolerate less confusion when feeding. Larger individuals, tolerating higher confusion costs, achieve higher feeding rates in high densities of uniform feed pellets.


2012 ◽  
Vol 69 (12) ◽  
pp. 1994-2006 ◽  
Author(s):  
Øystein Skaala ◽  
Kevin A. Glover ◽  
Bjørn T. Barlaup ◽  
Terje Svåsand ◽  
Francois Besnier ◽  
...  

Survival, growth, and diet were compared for farmed, hybrid, and wild Atlantic salmon (Salmo salar) families from the eyed egg to the smolt stage in River Guddalselva, Hardangerfjord, Norway. All individuals that survived until the smolt stage were captured in a Wolf trap and identified to one of the 69 experimental families using microsatellite markers. Survival of farmed salmon progeny was significantly lower than that of hybrids and wild progeny. However, survival varied considerably, from 0.17% to 6.4%, among farmed families. Egg size had an important influence on survival. Half-sib hybrid families with a farmed mother had higher survival when fathered by wild salmon than by farmed salmon. The overall relative survival of farmed families compared with that of their hybrid half-sib families fell from 0.86 in the second cohort to 0.62 in the last cohort with increasing fish density. Smolts of farmed parents showed significantly higher growth rates than wild and hybrid smolts. The overlap in diet among types of crosses demonstrates competition, and farm and hybrid progeny therefore will reduce the river’s capacity for production of wild salmon.


1991 ◽  
Vol 48 (10) ◽  
pp. 1896-1904 ◽  
Author(s):  
David J. Coughlin

Feeding strikes of Atlantic salmon (Salmo salar) alevins preying upon Daphnia are described using videorecording of synchronous lateral and antero-ventral views. Based on examination of characteristics such as aiming inaccuracy and capture distance, it is demonstrated that feeding behavior significantly improves during the first 2 wk after initiation of exogenous feeding. With increasing experience, young salmon tend to capture prey more quickly and with greater accuracy. First-feeding alevins use a body-ram feeding mode, relying on their swimming motion to overtake and capture prey. After 7–10 d of feeding, the fish change to a suction feeding mode that effectively uses suction generated by expansion of the orobranchial chamber to pull in prey from a distance. Also, feeding behavior of alevins raised on a commercial salmon feed lags developmentally behind the behavior offish raised on live food. This lag time is short (2–3 d), indicating that despite reports to the contrary, hatchery-raised fish do not require a Song time to learn to capture prey effectively in the wild.


1973 ◽  
Vol 30 (7) ◽  
pp. 985-989 ◽  
Author(s):  
A. M. Sutterlin ◽  
R. Gray

Based on recoveries from traps situated at a hydroelectric dam and a hatchery 1500 m downstream, the return location of hatchery reared and wild Atlantic salmon is examined. During the fall runs of 1971 and 1972, 97% of ascending wild salmon returned to the dam; only 3% were recovered at the hatchery. Despite the fact that the hatchery discharge contributed only 1/1000th of the river’s flow, 67% of the hatchery-reared fish returned to the hatchery and 33% to the dam.Tank tests demonstrated a clear-cut preference by hatchery adults for diluted hatchery effluent vs. river water. Wild fish showed no preference to either water. Well water, a component of hatchery effluent, was avoided by both hatchery and wild fish. Addition of CuSO4 to preferred water altered its effectiveness.


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