マカジキに関する水産海洋学的研究-2-サンゴ海における魚群の産卵状態

概要

論文の詳細を見る
Data of weight and appearance of gonads have been collected from tuna and billfishes caught by Japanese research and training vessels engaged in tuna long line survey. The present study is based on these data of female striped marlin, Tetrapturus audax, fished in an area extending between lat. 15°S and 30°S, long. 150°E and 170°E in the southern Coral Sea during 1966 through 1975. An examination of the gonad index of striped marlin in this area revealed the following information: 1. The examination of data reveals the gonad index being 1 at the initial stage of development, and exceeding 2.1 during the matured stage. 2. The ovaries start to mature sometime in late September or early October. 3. In October, mature fish (adults with mature gonads) are still relatively few in waters south of lat. 20°S. 4. The principal spawning season is between November and December. The main spawning ground appears to coincide with the fishing ground which extends between lat. 20° and 30°S, and between long. 154° and 160°E. Mature fish comprise 60-70 percent of the catches made in the area during this season. 5. The minimum size of spawning fish was estimated at about 143cm in length (eye to fork of caudal fin).
日本水産學會の論文