| Summary: | 碩士 === 國立臺灣海洋大學 === 環境生物與漁業科學學系 === 94 === Loligo chinensis is one of the main fishing targets of torch light fishery in the surrounding waters of Penghu in the Taiwan. Irrespective of its commercial important the biological information such as age, growth, reproduction and feeding habits are still absent. This study collected the specimens from the catch of the torch light boat to clarify the biological characteristics of the squid. The species of the squid were identified by their morphometric characters. Gonadal somatic index (GSI) and daily growth increments of statolith were measured to understand their reproduction behavior and growth performance. Meanwhile sea surface temperature and chlorophyll concentration in relation to fishing condition were analyzed. The growth equation of the squid was calculated as for female and for male. Juxtaposition the growth equation indicated the growth rate was similar between sexes in first five months of their life history. Since sixth month, the growth rate significantly differed between sexes. The mantle length of female squid will reach maximum after sixth month, while the male continues to grow. GSI show that the peak spawning period of the squid is between July and August. The catches of squid and location of fishing ground were related to the formation and movement of cold eddy. The area of cold eddy is lager in the periods of La Niña than in El Niño. In other words, during the periods of the La Niña, upwelling is stronger, and squid catch is higher in contrast to the periods of the El Niño. This squid move northward to the Taiwan Strait when the southwestern monsoon prevailing in spring. And reproduce in the surrounding waters of the Taiwan Bank in summer. While they move southward by the warmer water when the northeastern monsoon prevailing in late autumn and the China Coastal Water flows southward into the Taiwan Strait.
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