title: Scale analysis suggests frequent skipping of the second reproductive season in Atlantic herring.
abstract: A common assumption in fish studies is that iteroparous fishes, once mature, normally reproduce in all consecutive seasons. An analysis of scales from Norwegian spring-spawning herring collected between 1935 and 1973 revealed a strong under-representation (47% of expected) of second-time spawners on the spawning grounds. This reduction is not satisfactorily explained by errors in scale-reading, suggesting that the second reproductive season is frequently skipped. Skipping a season may relate to trade-offs between growth, current and future reproduction, and survival, which are likely to be particularly strong for young adult herring.
authors.affiliation: Institute of Marine Research, Nordnes, Bergen, Norway. g.engelhard@cefas.co.uk
authors.forename: Georg H
authors.initials: GH
authors.lastname: Engelhard
authors.forename: Mikko
authors.initials: M
authors.lastname: Heino
mesh_terms: D000367:Age Factors; D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D001267:Atlantic Ocean; D005399:Fishes / Q000502:physiology*; D012098:Reproduction / Q000502:physiology*; D012621:Seasons; D012726:Sexual Behavior, Animal / Q000502:physiology*