Sexual and geographical variation in life history parameters of the shorthorn sculpin |
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Authors: | J A Luksenburg †§ T Pedersen ‡ |
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Institution: | The Norwegian College of Fishery Science, University of Tromsø, N-9037, Norway;University of Groningen, Department of Marine Biology, Kerklaan 30, 9750 AA Haren, The Netherlands |
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Abstract: | A total of 293 shorthorn sculpins Myoxocephalus scorpius from Tromsø, northern Norway, were sampled between November 1998 and April 1999 to determine sex, total length, age, growth, maturity and mortality. Females grew to larger sizes ( L ∞=26·9 v. 18·5 cm), matured later (2 v. 1 year of age) at larger size (maturation length=16 v. 14 cm L T), and had lower instantaneous mortality rates (0·93 v. 1·20 year?1) than males. The life history parameters of shorthorn sculpins in northern Norway were more similar to the parameters of short-lived central European populations than to the parameters of the long-lived population of Newfoundland. This study confirms that northern Norwegian shorthorn sculpins exhibit sexual dimorphism as in other shorthorn sculpin populations. The relationships between growth pattern, age at maturity and mortality rates observed in the Tromsø population and in other shorthorn sculpin populations, correspond well with the predictions from a published life history model. |
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Keywords: | Myoxocephalus scorpius population dynamics life history growth mortality geographic variation |
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