Recruitment of an inherent piscivore, Japanese Spanish mackerel <i>Scomberomorus niphonius</i> (Scombridae)

Abstract

SUMMARY. 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 1.0 mm/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.

Ecological interactions between hatchery and wild fish: a case study based on the highly piscivorous Japanese Spanish mackerel

“…The released juveniles were reared from eggs that were artificially inseminated in early and late May, which was before the main JSM spawning season in the SIS (Sugino et al 2005). According to Shoji & Tanaka (2006) and Shoji et al (1999bShoji et al ( , 2002 Table 3. Scomberomorus niphonius.…”

“…According to studies on fishery biology (Kishida et al 1985, Kishida 1986, 1989, Kishida & Aida 1989, Nagai et al 1996, Kono et al 1997, Takemori et al 2005a and early life ecology (Shoji & Tanaka 2001, Shoji et al 1997, 1999a, 2002, the life history of JSM can be summarized as follows. This species has an estimated life span of > 6 yr and reaches maturity at 2 to 3 yr.…”