Age and growth of the blacktip sawtail catshark, Galeus sauteri, in the northeastern waters of Taiwan

• Main Authors: Chia-Ping Lin, 林家萍
• Other Authors: Kwang-Ming Liu
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/63045875269625973455

碩士 === 國立臺灣海洋大學 === 海洋事務與資源管理研究所 === 97 === The age and growth of blacktip sawtail catshark, Galeus sauteri, occurred in the northeastern waters off Taiwan were examined in this study. The specimens collected between Aug. 2007 and Dec. 2008 from Dasi fishing market, Yilan County. Age determination from vertebral band counting was based on 739 specimens (388 female and 351 male) and verified by length-frequency analysis of 4089 specimens (2122 female and 1967 male). Ranging from 8.3 cm to 49.8 cm in total length. The maximum likelihood ratio test indicated that these is a significant difference between sexes on Weight- length relation and can be expressed as followings: Female: TW=0.00209×TL3.1044 ,（r2=0.99, n=1052, p<0.05）,male: TW=0.00345×TL2.9448 ,（r2=0.99, n=884, p<0.05）. The formation of annuli for the species was found between November and December. Up to 14 and 12 bands were counted for females and males, respectively. The length at age data fitted in different growth equations. The best fitted growth equation for females and males was Gompertz and Robertson equation. The growth parameters: asymptotic total length L∞=53.2cm, growth coefficient kG=0.226 yr-1 for females; and asymptotic total length L∞=45.3cm, growth coefficient kR=0.366 yr-1 for males.