On Completing a Generation Cycle of the Grey Mullet, Mugil Cephalus, in Captivity 烏魚完全養殖試驗

Abstract

烏魚人工繁殖試驗始於1930年，迄今已有47年之歷史，此間經過許多學者專家之研究，已能適當地利用性腺激素促其成熟，然後擠卵、授精、孵化並育成魚苗。 鳥魚人工繁殖過程中，種魚之確保為最重要之一環。種魚之來源有二：一為池塘育成者，另一為捕自海上者。以前者為種魚而加以賀爾蒙處理並達成功的例子有二，但此等種魚之來源，亦即種苗亦係來自天然。此次，首次以三年前人工繁殖所得之魚苗育成種魚再加以賀爾蒙處理，結果有二尾成功，其中一尾由於自然排卵未能卽時予以授精，而無法達成人工繁殖之目的，但，由另一尾成功地育出第二代烏魚，亦卽完成所謂之「完全養殖」。「完全養殖」係指由卵而稚魚並育成為種魚，再由此等種魚採卵育出稚魚，此等一系列生活史之過程，均能由人工加以控制培育之養殖謂之。 此項關鍵性之突破，將解決烏魚種魚來源不足乙題，並充分證明人工育成之種魚繁殖之可能性，帶給烏魚人工繁殖工作一無限之美景。 The techniques of artificial propagation of grey mullet, Mugil cephalus, have been established recently and mass scale commercial application of these techniques is expected in the near future. Regrettably to this date, maintenance of grey mullet for a complete generation cycle in captivity has never been accomplished. The ”complete culture” can be defined as rearing for a complete generation cycle of an animal from eggs through larvae, juveniles, and adults to spawners and to reproduce the successive generations in captivity. The paper reports successful breeding of two grey mullets which grew up from fingerlings artificially propagated at the Tungkang Marine Laboratory three years ago. From one of them, 510,750 larvae were obtained and a yield of 1,661 artificially propagated grey mullets of second generation has been brought forth, marking the first success in ”complete culture” of the grey mullet. This break-through proved the feasibility of spawning artificially propagated tank-reared offspring, which will solve the problem of insufficient supply of spawners from the wild, and brings a promising future for the artificial propagation of grey mullet.