Female Mate Preference and Male Mating Success of Ayu Fish, Plecoglossus altivelis (Osmeridae) under a Promiscuous Mating System

Authors

  • Kei'ichiroh Iguchi,

    Corresponding author
    1. Fish Ecology Section, National Research Institute of Fisheries Science, Ueda, Nagano
      Fish Ecology Section, National Research Institute of Fisheries Science, Komaki 1088, Ueda, Nagano 386, Japan.
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      Iguchi, K. & Maekawa, K. 1993: Female mate preference and male mating success of ayu fish, Plecoglossus altivelis (Osmeridae) under a promiscuous mating system. Ethology 95, 193–201.

  • Koji Maekawa

    1. Fish Ecology Section, National Research Institute of Fisheries Science, Ueda, Nagano
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    • 3

      Iguchi, K. & Maekawa, K. 1993: Female mate preference and male mating success of ayu fish, Plecoglossus altivelis (Osmeridae) under a promiscuous mating system. Ethology 95, 193–201.


Fish Ecology Section, National Research Institute of Fisheries Science, Komaki 1088, Ueda, Nagano 386, Japan.

Abstract

The ayu, Plecoglossus altivelis, is known to show wide variation in adult body size. We examined the spawning behavior in experimental spawning groups of fish in which male body size varied. Males never competed with each other for females or spawning site, while females spawned repeatedly, 17–97 times depending on body size, with previous or novel males. Males exhausted their sperm after a single mating episode, on average, regardless of body size. Moreover, repeated sperm production apparently reduced the residual lifespan. Females preferred mating simultaneously with more than one male and allowed males of body size similar to their own to mate more frequently. Thus the largest male within a spawning group was not always the most successful at mating, but mating success of any given male appears to depend upon body size distribution of females within the population. Female mate preference has apparently evolved to ensure complete fertilization under circumstances where males have been selected to economize sperm output during any one mating episode.

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