| 英文摘要 |
Study and survey of ocean sunfish began in 2003. We have understood more about oceansunfish after 6 years.The study in age and growth of sharptail mola had been finished. Next step is to study the reproduction of Masturus lanceolatus. We had tagged three fishes in 2005, 2006 and 2007 at offshore of Hualien respectively. We are continuing to collect and analysis the fishy data and in additional beginning study of reproduction in sharptail mola by collecting ovary and testis in this year.
The total numbers of catch in sharptail mola are 1,625 and weight 207,105 kilogram and average weight per fish is 127.45（kg） by set net in 2008. The catches of sharptail mola this year are more than 2005 only. The numbers of mola between 51 to 100 （kg）are declined in this year.
We calculate that the age of maturity of male sharptail mola should more than 120（kg） in weight, older than age 9. The ovary does not develop until the standard length less than 135（cm）, about age 12 to 13. We think that the breeding season should be from May to Jane. All of catches are not maturity in the east waters of Taiwan except only one. The fish was female and 175（cm） in standard length, age 20 to 21.
Before the all study of, age and growth, reproduction, migration route, variation of population, have been finished. I suggest that to managed the resource of mola by limiting critical weight or length. We can make a practical management strategy in the future. |