| To compare the growth characteristics of sciaenid fishes, 7688 individuals of 6 sciaenid fishes were collected. 6619 of them were caught in Aug. 1985 to Oct.1988 with trawl in the Changjiang Estuary and adjacent waters. The others were in 1981 to 1982 caught with trawl by commercial fishing boat in the East China Sea. The big and thick otoliths of different sciaenid fishes were different in shape and structure. Through cutting experiment with otolith slicer, the optimum location and direction of cutting was determined. The results of linear regression analysis based on an exponential equation showed that body length of these 6 sciaenid fishes had close relationship to their body weight, but the A and B for these species were remarkable different. The value of A of females was larger than that of males of the same species and had positive relationship with L∞, and W∞; but was the contrary with the value of B.
By means of Walford’s graphical method and method of least squares and basing on von Bertalanffy growth equation, the growth parameters, K, L∞, W∞ and T0, of the six sciaenid fishes were calculated. The result showed that the value of K was negatively correlated to L∞. The species with larger L∞, and less K had larger growth rate and longer period of growth.
With seasonal growth model: l = L∞ [1 - e-K(t-T0)-(CK/2π)sin2π(t-TS)],the seasonal growth patterns of the six species were also simulated. It indicated that the body growth in winter and spring was much slower than that in summer and autumn. WP (winter point) of each species appeared in different time but appeared simultaneously with the opaque zone of their own otoliths respectively. |
