Intrapopulation Variation in the Breeding of Male Pink Salmon (Oncorhynchus gorbuscha) from a Lake Superior Tributary
- 1 January 1990
- journal article
- research article
- Published by Canadian Science Publishing in Canadian Journal of Fisheries and Aquatic Sciences
- Vol. 47 (1), 174-179
- https://doi.org/10.1139/f90-019
Abstract
Studies of breeding pink salmon (Oncorhynchus gorbuscha) from the Carp River, eastern Lake Superior, indicate that males seek fertilizations using two behavioural tactics. In 1985, a large run resulted in high breeding ground densities. During this run, males that resembled females were seen seeking ferilizations by sneaking rather than by competing for proximity to females. Morphological studies in 1985 confirmed the presence of males resembling females, their secondary sexual characters (hump height) being relatively less developed than in typical males. Although in poorer condition, such female-like males were reproductively mature, had returned to spawn at ages typical for this population, and had committed biomass to gonad no differently than had typical males. Furthermore, their spawning performance did not differ from typical males, as assessed both by the amount of gonad they retained unspawned at death and by their spawning ground life expectancies. In contrast, males attempting to sneak fertilizations were not observed during the small 1984 run when densities were low and males were generally in better condition than in 1985. Together, these results indicate that male pink salmon exhibit alternative breeding tactics. However, the demonstration of these tactics appears linked more to proximate factors (density and condition) than to divergent life history strategies as in other salmonid species.This publication has 18 references indexed in Scilit:
- Epizootics of thyroid hyperplasia in Lake Superior and Lake Erie pink salmon (Oncorhynchus gorbuscha (Walbaum))Canadian Journal of Zoology, 1988
- Incidence and Effects of Sea Lamprey (Petromyzon marinus) Parasitism on Breeding Pink Salmon (Oncorhynchus gorbuscha) from the Carp River, Eastern Lake SuperiorCanadian Journal of Fisheries and Aquatic Sciences, 1987
- Variation in Length and Body Depth of Pink Salmon (Oncorhynchus gorbuscha) and Chum Salmon (O. keta) in Southern British ColumbiaCanadian Journal of Fisheries and Aquatic Sciences, 1985
- Spawning Characteristics of Sympatric Populations of Steelhead Trout (Salmo gairdneri): Evidence for Partial Reproductive IsolationCanadian Journal of Fisheries and Aquatic Sciences, 1984
- Return of 1-Year-Old Pink Salmon in Michipicoten River, Eastern Lake SuperiorNorth American Journal of Fisheries Management, 1984
- Alternative Mating Tactics and Evolutionarily Stable StrategiesAmerican Zoologist, 1984
- A Classification of Alternative Reproductive Behaviors and Methods for Field-testing ESS ModelsAmerican Zoologist, 1984
- LOCAL POPULATION SIZE AS A DETERMINANT OF MATING SYSTEM AND SEXUAL COMPOSITION IN TWO TROPICAL MARINE FISHES ( THALASSOMA SPP.)Evolution, 1980
- Frequency of digging movements of female pink salmon before and after egg depositionAnimal Behaviour, 1960
- The development of the secondary sexual characters in the pink salmon (Oncorhynchus gorbuscha)Journal of Morphology, 1935