Journal of the Faculty of Fisheries and Animal Husbandry, Hiroshima University Volume 16 Issue 2
1977-12-25 発行

On the Age and Growth of the White Croaker Argyrosomus argentatus

イシモチArgyrosomus argentatusの年令と成長
Kakuda, Shunpei
Matsumoto, Kenji
A study was carried out to determine the age and the growth of the white croaker, Argyrosomus argentatus, which is an important resource for fishery in the Seto Inland Sea. This study, based on the samples caught in the central region of the Seto Inland Sea, is one of the serial studies on the fishery biology of the white croaker in the Sea.

General conclusions obtained in this study are as follows:
1) The relationship between standard length (L) of the fish and the mean radius (R¯) of the scales taken from the fixed body part is linear, and can be expressed as R¯ = 0.271 L - 0.176. In the scales from the same individual, "similarity" is recognized between scale radius and annulus radii.
2) The annulus is formed twice a year on the scales of the fish in winter and July, but the first annulus does not show in scales of many specimens.
3) The mean standard length of the fish of the Seto Inland Sea is 9.7, 15.7 and 20.2 cm at the full ages of 1 ,2 and 3 years respectively.
4) The spawning season lasts from June until August and its peak is in July.
5) Body weight (W) can be computed from standard length (L) by means of the relationship : W = 3.96×10-2 L 2.793 , where W is estimated round weight in grams and L is standard length in centimeters.
6) The growth of the fish can be described by BERTALANFFY's equation, Lt = 32.6 (1-e-0.307t- 0.046). And the fish gets the maximum growth rate in 2.83 years after spawn-time, when the standard length is 19.5 cm and the body weight is 159g.