台灣海域紅肉旗魚之年齡與成長研究

Abstract

本研究利用硬棘進行紅肉旗魚年齡與成長研究，並輔以耳石驗證背鰭硬棘中第一輪形成的位置。自2004 年11 月至2010 年4 月間於東港、南方澳和新港魚市場共量測1,416 尾紅肉旗魚體長資料，雄魚共量測731 尾，體長範圍介於92至220.5 公分，雌魚共量測558 尾，體長範圍介於95 至220 公分，性別未知的有127 尾。 將所量測的體長與體重資料經likelihood ratio test 檢定後，得知眼後眶尾叉長與體重關係在雌雄間並無顯著差異(P > 0.05)，因此合併體長體重關係式為W =4.68×10-6 EFL3.16。背鰭硬棘切片樣本合計517 個，其中雄性樣本291 個，雌性樣本226 個，扣除輪紋模糊、不規則及脈管化過於嚴重之樣本，共有447 個樣本成功判讀，其中雄魚241 個，判讀率為83%，APE 為8.96% ，CV 為11.80%；雌魚206 個，判讀率為91%，APE 為7.61%，CV 為11.54%。雌性與雄性最大判讀年齡皆為6 歲。背鰭硬棘一年所形成之輪紋數與輪紋形成期經邊緣成長率分析後得知紅肉旗魚在每年10 月至隔年1 月間形成一輪紋。 成長參數之推估分別利用Fraser-Lee’s 與Monastyrsky 法估算紅肉旗魚雌雄各年齡的逆算體長，經計算後並套入standard von Bertalanffy 與generalized von Bertalanffy 成長方程式以非線性迴歸法估算其成長參數。結果顯示以Monastyrsky法估算之逆算體長套適generalized von Bertalanffy 成長方程式所估計之成長參數 較為適當，而所推估出來的雄性與雌性成長方程式經由殘差平方和分析法比較雌雄別成長參數後，得知雌雄間之成長並無顯著差異(P > 0.05)，雌雄合併之成長方程式為 ( 1 ) 263.44(1 0.04(1 2.05)(t 0.40) ) 1 2.05 tL = − e− − − − 。

Age and growth of striped marlin in waters off Taiwan were examined based on counts of annual growth rings on cross sections of the fourth spine of the first dorsal fin. In total, 1,416 length samples of striped marlin were collected from November 2004 to April 2010, of which 731 were males , 558 were females, and 128 were sex unknown. The length-weight relationships between sexes were combined (W = 4.68× 10-6 EFL3.16) because of no significant difference (P > 0.05). There were 241 (of 291, 83%) spines for males and 206 (of 226, 91%) for females aged successfully. The time of the formation of the first ring was validated by reading the daily rings on the cross section of the otolith of striped marlin. The APE (average percent error) is 8.96 and 7.61% and the CV (coefficient of variation) is 11.80 and 11.54% for male and female striped marlin respectively. The analysis of MIR (marginal increment ratio) suggested that the growth bands of striped marlin formed once a year (during October to next January). The back-calculated lengths for each age were computed using the Fraser-Lee's and Monastyrsky methods, and then used to fit the standard and generalized von Bertalanffy growth equations (VBGEs). Results showed that the fits to generalized VBGE were better (based on AIC statistics) than those for standardized VBGE. The estimated growth equations for male and female striped marlin were not statistically different through the analysis of residual sum of squares (ARSS, P > 0.05). The sex-combined generalized VBGE of striped marlin is estimated as follows: ( 1 ) 263.44(1 0.04(1 2.05)(t 0.40) ) 1 2.05 tL = − e− − − −