英文摘要 |
The study analyzed thirty-three stomachs of swordfish sampled from tropical Indian Ocean in 2006. Four newly recorded prey items, including Nansenia sp. (pisces), Taningia danae (cephalopod), Pelagopenaeus balboae (crustacea) and Carinaria cristata (heteropod) were obtained. The diet composition dominate by fish, accounting for 85% of occurrence (O%) and 65% of number (N%), followed by cephalopod (O%=73, N%=16), crustacea (O%=21, N%=5.8) and heteropod (O%=3.0, N%=0.25). However, estimating by the weight percentage (W%) became cephalopod (W%=52)>fish (W%=47)>crustacea (W%=1.2) and heteropod (W%=0.03). The food composition shifted by size, swordfish with fork length (FL) smaller than 200 cm fed mainly on fish, whereas the fish larger than 200 cm FL ate more cephalopod. In addition, gender preference of diet was also found, female fish (O%=50;N%=18;W%=14) ate more crustacea than the male fish (O%=14;N%=6;W%=4). |