Files and links (1)
Rights Statements InC/1.0 , Open Access
Journal article
Bilateral asymmetry, sexual dimorphism, and nematode parasites in mature male sockeye salmon Oncorhynchus nerka
Northwest science., Vol.71(4), pp.305-312
1997
Handle:
https://hdl.handle.net/2376/1230
Abstract
The extent of bilateral asymmetry of 3 10 mature male sockeye salmon (Oncorhynchus nerka) from 6 Alaskan populations was determined to investigate the relationship between fluctuating asymmetry in paired morphological characters and physical traits (body size and shape) that seem to signal male quality. There was marked variation within and among populations in body size and morphology (e.g., body depth), but no differences in the overall level of asymmetry were detected among the populations, nor between the two systems investigated (lakes Aleknagik and Iliamna). The counts or measurements of a number of the traits evaluated for asymmetry varied among populations, but most differences were attributable to population-specific variation in body size. The six populations exhibited marked similarities in the patterns of asymmetry. Three paired characters (length of pectoral fins, number of branchiostegals, and number of teeth) were directionally asymmetric, indicating a genetic basis for asymmetry rather than an environmental influence. Two other paired characters (ventral fin length and number of enlarged teeth) were bilaterally variable but not correlated with any attribute of male quality. Based on the low variation between the different populations in level of asymmetry, we conclude that either stress does not influence asymmetry levels in sockeye salmon or that these populations are under similarly low levels of stress. We also explored the relationship between biomass of a nematode parasite (Philonema oncorhynchi) and asymmetry. The weight of parasites was related to fluctuating asymmetry in the ventral fin length but was not related to fluctuating asymmetry in number of large teeth
Metrics
283 File views/ downloads
534 Record Views
Details
- Title
- Bilateral asymmetry, sexual dimorphism, and nematode parasites in mature male sockeye salmon Oncorhynchus nerka
- Creators
- OleKristian Berg (Author)Milo D. Adkison (Author)Thomas R. Quinn (Author)
- Publication Details
- Northwest science., Vol.71(4), pp.305-312
- Academic Unit
- Northwest Science
- Publisher
- WSU Press
- Identifiers
- 99900501752801842
- Copyright
- In copyright ; openAccess ; http://rightsstatements.org/vocab/InC/1.0/ ; http://purl.org/eprint/accessRights/OpenAccess
- Language
- English
- Resource Type
- Journal article