Population and maturation dynamics of the swordtip squid (photololigo edullis) in the southern east chaina sea
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Reproductive biology and seasonal distribution of the swordtip squid (photololigo edulis) in the northeastern waters of Taiwan were studied,based on the samples and fishery data from the troch-light fishery between 52003 and 2005 the swordtip squid only occurred in the Kuroshiro current and reached the coastal waters of Taiwan in the January and February from march to june, its distributional range extended to 27°N and 124° E as the front (thekoshiro current met the mainland china coastal current) move northward the squid moved southwestward as the front retreated to 25°N and 123°E from july to September. After October,its was mainly distributed in ther front area which shifted southwestward as the front retreated to 25°N and 123°E from july to September . After October, its was mainly distributed in the front area which shifted southwestward at this time
Both percentage of the mature individuals and gonado – somatic index (GSI) of the swrodtip squid were hight in the spring and autumm and low in summer indicating two spawning seasons per year.Comparison of mantel length (ML),body weight (GW) of mature specimens in spring and autumm indicated that individuals of autumm spawning group were larger and heavier than those
Of the spring spawning group the GSI between the two spawning groups was not different in the females but different in the males . high GSI and high percentage of mature (stage IV) individuals
In the area suggest that the inshore water off northern Taiwan between 25.5° N and 26.5° N 121.5°E and 122.5 E cloud be a spawning ground for the swordtip squid.