Effect of prey concentration on growth of piscivorous Japanese Spanish mackerel Scomberomorus niphonius larvae in the Seto Inland Sea, Japan

Japanese Spanish mackerel, Scomberomorus niphonites, larvae feed almost exclusively on fish larvae from the first-feeding stage. The relationship between the growth of S. niphonius larvae and concentration of major prey organisms of the larvae, clupeid larvae, was investigated in the Sea of Hiuchi, the central Seto Inland Sea, Japan, from 28 to 29 May 1997. Water temperature, salinity, and the concentration of clupeid larvae had no significant effect on the S. niphonius larval concentration. Mean growth rate of S. niphonius larvae varied between 0.38 and 0.64 mm day(-1). The temperature and salinity had no significant effect on the mean larval growth rate while there existed prey concentration-dependent growth at lower prey concentration. The relationship between the mean larval growth rate (G(m)) and concentration of clupeid larvae (C-C) was expressed by a logarithmic equation: G(m)=0.037 log C-C + 0.441 (n=16, r(2)=0.519, P<0.01).