農業部水產試驗所全球資訊網

白腹鯖 (Scomber japonicus) 為臺灣西南海域扒網漁業重要經濟魚種之一。本研究於2020年11月至2021年10月期間按月至澎湖扒網漁船採樣，共採集692尾樣本，雌雄分別為305尾及387尾，性比為44.1%，雌雄比例有顯著差異 (p < 0.05)。雌魚尾叉長 (FL) 介於 139.1–352.0 mm，體重 (body weight, BW) 介於34.3–562.3 g，體長與體重之關係式為BW = 1.716 × 10^-5 FL^2.942 (n = 305)；雄魚尾叉長 (fork length, FL) 介於141.9–344.0 mm、體重介於34.0–519.5 g，體長與體重之關係式為BW =2.435 × 10^-5 FL^2.875 (n = 387)。根據卵巢生殖腺外部型態及生殖腺指數 (gonadosomatic index, GSI)，2020年11月至2021年4月均有出現完熟期，GSI平均值範圍介於0.18–12.15間，自2020年11月至隔年4月維持在較高值3以上、卵巢組織切片及卵徑頻度測量等數據，推估白腹鯖生殖期為11–4月，2月份所採樣本發現水卵，推估高峰在2–4月。孕卵數為6,006–596,452，批次孕卵數為2,653–79,287粒卵，卵徑介於0.14–1.25 mm。雌魚50% 性成熟體長為245.8 mm。

摘要abstract(英) The Blue mackerel (Scomber japonicus) is an important economic species in southwest Taiwan’s Danish seine fishery industry. From November 2020 to October 2021, a total of 692 samples were collected on a monthly basis. Among them, 305 were male and 387 were female, for a significantly different male-to-female sex ratio of 44.1% (p < 0.05). The fork length (FL) of female fish ranged from 139.1 to 352.0 mm; the body weight (BW) ranged from 34.3 to 562.3 g. The length-weight relationship was BW =1.716×10-5 FL2.942 (n=305). The FL of male fish ranged from 141.9 to 344.0 mm; the BW ranged from 34.0 to 519.5 g. The length-weight relationship was BW =2.435×10-5 FL2.875 (n=387). Based on the external ovary morphology, full maturity was observed from November 2020 to April 2021, with the gonadosomatic index (GSI) averaging between 0.18 and 12.15. From November 2020 to April 2021, the GSI remained above 3. Data from ovarian tissue sections and oocyte diameter frequency measurements suggest that the blue mackerel’s reproductive period occurred from November to April, peaking at February to April, as water eggs were found in samples collected in February. The egg count ranged from 6,006 to 596,452, the batch fecundity ranged from 2,653 to 79,287 ova, and the oocyte diameter ranged from 0.14 to 1.25 mm. The FL at 50% sexual maturity for females was 245.8 mm.