1) To study growth variation of fishes, coefficient of variation (
CV) of standard length (
SL) were calculated using the small-scale random samples of black sea bream (
Acanthopagrus schlegeli), Japanese flounder (
Paralichthys olivaceus) and mud dab (
Limanda yokohamae) from hatching to 80-120 days. Both
SL and
CV curves were drawn by the polynomial equations, and both theoretical daily increments of
SL (Δ
SL) and
CV (Δ
CV) were calculated.
2)
CV of black sea bream represents a rising curve as the fish grow. Theoretical Δ
SL always increases, but that of Δ
CV shows only slight increase after initial decrease.
3) Initially increased
CV of Japanese flounder turned into decrease from 23 days after hatching. The period of decrease of
CV in the postlarva corresponds with the period of turning into the demersal habit from the planktonic one. Both theoretical Δ
SL and Δ
CV curves fluctuate as if periodically accompanying a certain time-lag.
4) Initially increased
CV of mud dab turned into decrease from 9 days after hatching, then again increased from 28 days after hatching. In the same way as Japanese flounder, the period of decrease of
CV in the postlarva corresponds with the period of turning into the demersal habit from the planktonic one. Both theoretical Δ
SL and Δ
CV curves fluctuate similarly to Japanese flounder.
View full abstract