中西太平洋產鮪類仔稚魚的組成與空間分布

吳繼倫、劉國強、藍揚麒、郭慶老 (2013) 。中西太平洋產鮪類仔稚魚的組成與空間分布。水產研究，頁1-13。

       為瞭解中西太平洋海域鮪類仔稚魚的種類組成、時空分布、生態習性及可能產卵海域，本研究於2000年7月及2001年6月，使用水試一號試驗船，以IKMT仔稚魚拖網分別在上述海域進行兩航次的鮪類仔稚魚採樣調查研究；採樣後依據鮪類仔稚魚體表呈現的黑色素胞分布特徵判定其種類，並予以拍照和記錄體長。兩航次共計採獲鮪類仔稚魚90尾，包括黑鮪 (Thunnus orientalis) 11尾、大目鮪 (T. obesus) 20尾、黃鰭鮪 (T. albacares) 54尾及長鰭鮪 (T. alalunga) 5尾。黑鮪體長在3.4 ~ 8.1 mm、大目鮪體長在2.9 ~ 9.8 mm、黃鰭鮪體長在3.8 ~ 7.8 mm、長鰭鮪體長在4.1 ~ 8.1 mm。由於所採得的鮪類仔稚魚多處於孵化不久的階段，因此可推定6 ~ 7月應屬黑鮪、大目鮪、黃鰭鮪及長鰭鮪的共同產卵期間，且其產卵海域涵蓋臺灣東部海域。

Two cruises (offered by R/V Fishery Researcher I) were conducted in July 2000 and June 2001 in order to examine the geographical distribution pattern of tuna larvae in the central-western Pacific Ocean. At each station, IKMT and CTD were deployed to collect ichthy-plankton samples and to measure relevant oceanographic factors. Totals of 33 and 34 stations were surveyed in 2000 and 2001, respectively. The latitude reached to 10°N in the south, while the longitude reached to 141°E in the east. Tuna larvae were identified by examining patterns of melanophore which appeared on the body. A total of 90 tuna larvae were obtained, including 11 bluefin tuna (Thunnus orientalis), 20 bigeye tuna (T. obesus), 54 yellowfin tuna (T. albacores), and 5 albacore (T. alalunga). No significant differences in the mean standard lengths for the four tuna species were found between the samples from 2000 and 2001. The standard lengths of bluefin tuna, bigeye tuna, yellowfin tuna, and albacore larva ranged from 3.4 ~ 8.1 mm, 2.9 ~ 9.8 mm, 3.8 ~ 7.8 mm, and 4.1 ~ 8.1 mm, respectively. The spawning period for tunas was considered from June to July. Furthermore, the spawning grounds of tunas were also suggested to be adjacent to the eastern waters off Taiwan.