Recruitment of an inherent piscivore, Japanese Spanish mackerel Scomberomorus niphonius (Scombridae)

抄録

The hypothesis that prey abundance and larval growth rate are related to recruitment was tested in Japanese Spanish mackerel in the central Seto Inland Sea, Japan. The relationships among larval abundance, growth rate, prey fish (clupeiform larvae) abundance, and the catch per unit fishing effort (CPUE) of the subsequent 1-year-old fish were examined from 1995 to 1999. A significant, positive correlation was found between the larval growth rate and the CPUE, but not between the larval abundance and the CPUE. There also existed a significant positive correlation between the abundance of clupeiform larvae and the larval growth rate, which varied from 0.4 to 1.0mm/day. Both the larval growth rate and the CPUE were higher in 1995 and 1999, when the period of peak occurrence of clupeiform larvae timed well with that of the mackerel larvae. It has been concluded that the prey abundance during the early larval period is one of the most important determinants of the growth and recruitment of Japanese Spanish mackerel.