The feeding habit of Cholen macrolepis in the area of Kaohsiung harbor, Southern Taiwan

• Main Authors: Wu, Ling-I, 吳玲毅
• Other Authors: Chen, Meng-hsien; Yang, Jui-sen
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/88808375947598475607

碩士 === 國立中山大學 === 海洋資源學系 === 84 === This study investigated some aspects pf feeding ecology of grey mullet, Chelon macrolepis, in Kaohsiung harbor and its nearby co -astal waters, southern Taiwan. Monthly sampling were conducted from July 1994 to August 1995. The sampling area included the Kaohsiung River, its harbor area and the nearby offshore area. Adult fishes were caught by gill net and the juveniles were collected by pond net at one site by the harbor from April to June 1995. The fishes were measured total length and body weight and then dissected out stomach. Stomach content weight index, pre- centage of empty stomach, sand content index and organic content index were calculated. The composition of feeding was examined with microscopy. Moreover, the microstructures of the gill raker were examined througt the scanning electromicroscopic technique. Among the 1415 fish samples in three locations no significant di -fference of SCWI was found between male and female fishes. How- ever, the SCWI in the harbor area was significantly higher than that of off shore in any month. The ES% values in two area were in contract to the SCWI. The monthly variation of the SCWI re- vealed that the highest and lowest feeding intensity were found in May and December, respectively. The major food composition of C. macrolepis was different between sites. The results also rec- ealed a dietary shift from omnivorous to herbivorous between the juvenile and adult. The food composition of the grey mullet also varied seasonally which was correlated to the natural environ- ment. the dietary shift between the juvenile and adult was eluci -dated by the increase of the length and loop number of aliment- ary cannel. The distance between the gill raker, secondary pro- cesses, tertiary expansions did not show any decrease correspon- dent to the increase of fish size. However, the finest distance at the tertiary expansions of the third and fift gill rakers were finest enough to filter the food particles for any size of grey mullet.