Sex-specific life history strategies in capelin ( Mallotus villosus )?

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Author: Huse, Geir
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1998
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Barents Sea
• Online Access: http://dx.doi.org/10.1139/f97-275; http://www.nrcresearchpress.com/doi/pdf/10.1139/f97-275

The life history of capelin (Mallotus villosus) is presently suggested to be sex specific: while males follow a semelparous batch-spawning strategy, females are iteroparous. This hypothesis is based on predictions from a life history simulation model of Barents Sea capelin that shows that iteroparity is more profitable than semelparity for females, but for males, semelparity with several matings with females may be as profitable as iteroparity. These predictions are supported by (i) reports of males mating with several females during a spawning season, (ii) males having a lower gonadosomatic index than females and instead spending their energy on mating and somatic growth, and (iii) an observed higher mortality for males after spawning. The Darwinian fitness of female capelin is limited by the amount of eggs they can carry, and offspring production may only be increased by undertaking several spawning seasons with yearly intervals. Added together, these indices suggest that male and female capelin follow different life history strategies.