Differences in Morphology and Behavior between Juvenile Coho Salmon (Oncorhynchus kisutch) Rearing in a Lake and in its Tributary Stream

1989 ◽  
Vol 46 (8) ◽  
pp. 1406-1414 ◽  
Author(s):  
Douglas P. Swain ◽  
L. Blair Holtby
Keyword(s):  
Aggressive Behavior ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Mirror Image ◽  
Laboratory Rearing ◽  
Pectoral Fins ◽  
Inlet Stream ◽  
And Behavior ◽  
Lake Type ◽  
Total Behavior

Juvenile coho salmon (Oncorhynchus kisutch) rear both in Mesachie Lake, B.C., and in its inlet stream. The duration and frequency of aggressive behavior were greater among stream-rearing than lake-rearing juveniles in mirror image stimulation and stream tank tests of agonistic behavior. Lateral displays made up a higher proportion of total behavior among the stream-rearing fish compared with the lake-rearing fish. Lake-type fish had more posteriorly placed pectoral fins, shallower bodies and smaller, less brightly colored dorsal and anal fins than did stream-type fish, even after 2 mo of laboratory rearing in a common environment. Diminished aggression, a shift in aggressive behavior away from lateral displays, a more streamlined shape, and reduced coloration, all appear to be adaptations to a schooling lifestyle in the open waters of the lake.

Mirror-Elicited Agonistic Behaviour and Body Morphology as Predictors of Dominance Status in Juvenile Coho Salmon (Oncorhynchus kisutch)

1993 ◽  
Vol 50 (3) ◽  
pp. 676-684 ◽  
Author(s):  
L. Blair Holtby ◽  
Douglas P. Swain ◽  
G. Michael Allan
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Fork Length ◽  
Mirror Image ◽  
Large Fish ◽  
Agonistic Interactions ◽  
Dominance Status ◽  
Body Depth ◽  
Body Morphology ◽  
Eventual Dominance

We tested whether body morphology and aggressive behaviour, measured through mirror image stimulation (MIS), could predict the eventual dominance status of juvenile coho salmon (Oncorhynchus kisutch) tested in paired contests and in stream tank interactions with several individuals. Dominance in paired contests was predicted by MIS behaviour on the fifth observation day using newly emerged juveniles and by MSS behaviour on the first observation day using 7-wk-old juveniles. In both.w420020 dstrials, deeper bodied fish tended to be dominant. In the stream tank tests, the MIS behaviour SAM (swim-against-mirror) and fork length were the best predictors of dominance. Large fish with high levels of SAM tended to be dominant. After removing the effects of fish size, neither body depth nor fin size consistently predicted dominance ability. SAM was positively correlated with overt aggressive behaviours in stream tanks but not with lateral displays, juvenile coho salmon appeared to react to conspecifics and to their own mirror images in a quantitatively similar way, and both MIS behaviour and body morphology were significant predictors of the outcome of agonistic interactions among individuals.

Variation in Agonistic Behavior between Newly Emerged Juveniles from Hatchery and Wild Populations of Coho Salmon, Oncorhynchus kisutch

1990 ◽  
Vol 47 (3) ◽  
pp. 566-571 ◽  
Author(s):  
D. P. Swain ◽  
B. E. Riddell
Keyword(s):  
Agonistic Behavior ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Its Region ◽  
Population Level ◽  
Mirror Image ◽  
Aggressive Display ◽  
Wild Populations ◽  
Breeding Programs ◽  
Stimulation Tests

We compared agonistic behavior of newly emerged coho salmon (Oncorhynchus kisutch) between hatchery and wild populations using mirror image stimulation tests. We used hatchery populations from two different regions of Vancouver Island B.C., each matched with a wild population from its region. In both comparisons, hatchery juveniles were more aggressive than wild juveniles. Rates of aggressive display increased with time since emergence for both hatchery and wild fish, as did the differences in behavior between the two types. By the sixth day of observation (13 d postemergence), the overall effect of fish type was highly significant for all aggressive behaviours. Since the individuals compared were reared from eggs under identical conditions, these differences are presumably genetic. Comparisons involved relatively few families from each population. However, because heritability was moderate to low within populations, and variance between population types exceeded variance among families within populations, these results indicate real differences at the population level. These results may have important implications for programs to rebuild wild populations using hatchery transplants and for selective breeding programs to develop domestic stocks of coho.

Induced ovulation in coho salmon (Oncorhynchus kisutch). I. Further studies on the use of salmon pituitary preparations

Aquaculture ◽  
1981 ◽  
Vol 26 (1-2) ◽  
pp. 117-127 ◽  
Author(s):  
George A. Hunter ◽  
Edward M. Donaldson ◽  
Helen M. Dye
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Induced Ovulation

Physiological Response of Juvenile Coho Salmon (Oncorhynchus kisutch) and Rainbow Trout (Salmo gairdneri) to Handling and Crowding Stress in Intensive Fish Culture

1976 ◽  
Vol 33 (12) ◽  
pp. 2699-2702 ◽  
Author(s):  
Gary A. Wedemeyer
Keyword(s):  
Rainbow Trout ◽  
Feeding Behavior ◽  
Coho Salmon ◽  
Physiological Stress ◽  
Oncorhynchus Kisutch ◽  
Fish Distribution ◽  
Salmo Gairdneri ◽  
Crowding Stress ◽  
Normal Feeding ◽  
Intensive Fish Culture

Moving 4–5-in. coho salmon (Oncorhynchus kisutch) held in soft (20 ppm CaCO3) water from the relatively light loading density of 0.5 lb/ft3 to 1, 2, or 4 lb/ft3 (density index, DI = 0.1, 0.2, 0.4, 0.8) caused significant stress as indicated by loss of feeding behavior, but only minimal physiological disturbances, as indicated by lack of hyperglycemia or hypochloremia. However, moving them to 6 or 12 lb/ft3 (DI = 1.2, 2.4) caused significant physiological stress which required at least a week for recovery. Smolting coho salmon were physiologically stressed by population densities of 1 lb/ft3 or more and a subclinical corynebacterial kidney infection was activated. Rainbow trout (Salmo gairdneri) (4–5 in.) were physiologically stressed when moved and held at 1 lb/ft3 or more but retained normal feeding behavior. This indicates that handling and crowding stress will be minimized in softwater areas if densities in fish distribution trucks or in ponds or raceways during disease treatments are held to 0.1–0.5 lb/gal.

scholarly journals Hyperbilirubinemia of Coho Salmon Oncorhynchus kisutch Infected with Erythrocytic Inclusion Body Syndrome (EIBS) Virus

1994 ◽  
Vol 60 (5) ◽  
pp. 519-521 ◽  
Author(s):  
Tadashi Sakai ◽  
Hisashi Murata ◽  
Kiyoshi Yamauchi ◽  
Kiyotaka Takahashi ◽  
Nobuaki Okamoto ◽  
...  
Keyword(s):  
Inclusion Body ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch

Ionic regulation in migrating juvenile coho salmon, Oncorhynchus kisutch

1968 ◽  
Vol 26 (2) ◽  
pp. 381-398 ◽  
Author(s):  
Harry M Miles ◽  
Lynwood S Smith
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Ionic Regulation
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