The growth and reproduction of the Portuguese oyster, Crassostrea angulata, in Taixi and Qigu, Taiwan

• Main Authors: Jia-chi Lu, 盧佳綺
• Other Authors: Li-Lian Liu
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/86934114159658718410

碩士 === 國立中山大學 === 海洋生物研究所 === 101 === Culture of oyster Crassostrea angulata in Taiwan is over hundred years, and the major cultural sites are along the west coast. This study was aimed to investigate the effects of environment and genetic inheritance to growth and reproduction through transplant experiments conducted in Taixi and Qigu during the period of June 2011 to July 2012. The shell length, shell weight and total weight increased with time, base on monthly examination on the groups of Taixi (T), TaixiQigu (T’), Qigu (Q) and QiguTaixi (Q’). Although group Q had the greatest shell length, shell weight and total weight, their regression slopes were significantly smaller than all other groups. The greatest relative increment of shell weight was in the first month and group T had the highest increment compared with others. The highest and lowest CI values were in groups T and Q, respectively. Sex ratio of oysters cultured in Taixi (groups T and Q’) showed male-biased trend while female-biased trend was observed in Qigu (groups Q and T’). In addition, the GSI values increased earlier in Taixi than in Qigu. A similar pattern in GSI variations has been observed in the native and transplanted groups. As a whole, genetic and environmental factors both had influence on oyster growth. Group Q had the lowest weight gain which might be resulted from high cultural density in Qigu. Thus, each individual obtained less amount of food than in Taixi. After a half-year culture, the reproductive cycle of transplanted oysters was similar to local groups indicated the contribution of environment is more important than genetics to oyster reproduction in later cultural stages.