| 英文摘要 |
This study is aiming to investigate the age and growth of Indian albacore tuna, based on length frequency analysis and otoliths reading methods.
The historic length data and catch statistics of the Indian albacore were kindly made available by the Overseas Fisheries Development Council (OFDC). Owing to the apparent peaks in the length frequency distributions were observed for the year of 1980-1983, the length data of this time period were adopted to estimate the age and growth of Indian albacore. These data were debugged, summed up and expanded to the total albacore catch in numbers. The Multifan program was applied to estimate the von Bertalanffy’s growth equation, and the K, L∞ and t0 were then obtained as 0.127, 139.5 cm and -1.12 yr, respectively. In addition, 49 otolith samples of albacore were provided by the observers worked on board. The otoliths were then examined under microscope after preliminary treatments of otoliths, such as cleaning, embedding, and grinding. Some of these otoliths were difficult to identify their rings, and only 29 of them were carried on the ring-count procedures. Each of these otoliths was examined three times independently, and 25 of them showed consistent results of ring-count. Based on the length of the fish and their ring-count on otoliths, the mean lengths of albacore at age of 4-11 were obtained, respectively. These estimated lengths at age were found to coincide the von Bertalanffy’s growth equation derived from the length frequency analyses. |
