Effects of prey concentration, light regime, and parental origin on growth and survival of herring larvae under controlled experimental conditions

Abstract

Abstract Folkvord, A., Høie, H., Johannessen, A., and Solbakken, T. 2009. Effects of prey concentration, light regime, and parental origin on growth and survival of herring larvae under controlled experimental conditions. – ICES Journal of Marine Science, 66: 1702–1709. Experiments were undertaken to study the combined effects of environmental (prey concentration and photoperiod) and genetic (parental spawning season) factors on growth and survival of herring larvae. During the experimental period, constant prey concentrations were maintained at one of the two nominal levels, under either a spring or an autumn light regime. Eggs of one autumn-spawning North Sea Buchan female herring were fertilized either with cryopreserved sperm from three Norwegian spring-spawning males or with fresh sperm from three Buchan males. Larvae of the two groups (the hybrids marked with alizarin) were mixed in replicated treatment tanks, thus ensuring identical environmental conditions. Mean larval growth rates were mostly influenced by food availability, but the hybrids grew significantly faster than the pure autumn-spawned offspring. In addition, the hybrids experienced a survival advantage at low prey concentrations. Hybrid survival was also somewhat better at high prey concentrations under a spring photoperiod than the corresponding group under an autumn photoperiod, suggesting a possible genetic adaptation to seasonal light conditions. The experiment documents the viability beyond first-feeding of offspring from parents with different spawning periods. The results are discussed in relation to herring metapopulation structure.