Abstract

Induced breeding experiments of Nikishigoi (koi carp), Cyprinus carpio were conducted in mature males and females by administrating a single intramuscular injection of ovaprim at a dosage of 0.3 mL/kg weight. Spawning was observed six hrs after the injection at ambient temperature (26-28oC). The fertilized eggs were adhesive and transparent with diameter ranging between 0.9 mm and 1.10 mm. Incubation period was 73.00hrs. The hatchlings were transparent and measured 2.7-2.9 mm, with a large oval head, a well defined yolk sac and short tail. The yolk got fully absorbed within 3 days and by this time mouth formation was complete and the larvae started exogenous feeding. After 20 days the length of fry ranged between 10 mm and 12 mm and after 35 days length of the fingerlings ranged from 30-35 mm and appeared just like an adult in all respects except sexual maturity.

中文摘要

錦鯉 (Cyprinus carpio) 人工繁殖是將成熟的雌魚以肌肉注射的方式注射一劑ovaprim (每公斤魚體重注射0.3 mL)。在26-28℃的溫度下，注射六小時後即會產卵。受精後的卵呈透明狀具黏性，直徑在0.9 mm 到1.10 mm 之間。73 小時後仔魚即會孵化，魚苗體長2.7-2.9 mm，身體呈透明狀，頭卵圓型，卵囊相當完整，尾巴很短。卵黃在三天內會被吸收，在這期間，仔魚口部發育完全後會開始覓食。20 天後，仔魚可長到10 mm到12 mm，35 天後，稚魚體長30-35 mm，此時的錦鯉除了尚未性成熟外，樣子已和成魚相似。

Keyword: Breeding behaviour, ontogenic events, koicarp, 繁殖行為, 個體發生, 錦鯉