Age and Growth of the Ribbon Fish in the Kii Channel

Abstract

The relationship between age and growth of the ribbon fish, Trichiurus lepturus Linné, which is most common among the bottom fishes in the Kii Channel in recent years, have been studied. The study was based on 3,739 specimens of otoliths and a size composition analysis of 10,591 specimens from randomly sampled fish, caught by small type trawlers between April, 1972 and August, 1974. The results are summarized as follows: 1) Ribbon fish schools in the Kii Channel usually consist of fishes from two broods, the spring-born and the autumn-born. 2) The annual ring marks on otolith are formed in the spawning season in spring from April to June. 3) Hence the radius of the first ring (r1) in the autumn-born group are smaller than that of the spring-born group. Thus, by the size of the first ring radius, the ribbon fish schools are divided into two groups of spring-born (r1≥2.3 mm) and autumn-born (r1<2.3mm). 4) The growth equation for spring-born group is estimated as follows; [formula omitted] Because of inadequate number of specimens for the autumn-born group, the growth equation is not estimated here. 5) The calculated values of body length from this equation are larger by one age than those body lengths discribed in the former studies. © 1976, The Japanese Society of Fisheries Science. All rights reserved.