ISSN:
1095-8649
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Variation in growth rate, age at maturity, reproductive life span and reproductive investment was investigated in females only in seven populations of roach, Rutilus rutilus, in Norway. The growth rates of mature female roach were low, varying for most populations between 10 and 14 mm year.1 At the most northern locality the growth rate was only 5.6 mm year1. Individual fecundity and gonadosomatic index (GSI) varied unsystematically between populations, but it was evident that the population with the lowest growth rate also had the lowest individual fecundity and GSI. Egg weight also varied between populations, the most northern population had a medium egg weight, thus, in harsh climatic conditions egg number is sacrificed for a relatively high egg weight. We found no further evidence for a trade-off between egg number and egg size. Fecundity increased with length in all populations, whereas the variation in egg size and GSI for most populations did not covary with length or age. This fact, together with the high age at maturity in all populations and the long reproductive life spans supports the bet-hedging theory of life-history evolution. This is further supported by the fact that we did not find any correlation between the growth rates and the different descriptors of fitness.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1095-8649.1990.tb03589.x
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