On the 20th August 2020, 3 Little Fish Sdn Bhd did a Haruan or Snakehead Fish (Channa striatus) Breeding in Semenyih using Ovaprim. The purpose of this trip was to show farmers how to use Ovaprim to breed Haruan Fish. Fish were obtained from the culture ponds and weights were between 1.0-2.5kg. Before injection, each fish was anesthetized with Tricaine-S and checked to make sure they were healthy and in good condition. Once they were checked, their sex were determined by checking the genital papillae and weighed. Fish were then placed on a table lined with a towel to gently enclose the fish so that it would not slip off the table. The eyes of the fish were also covered to reduce the stress on the fish. The appropriate dosage of Ovaprim was prepared and injected. Female fish were injected with 0.5ml/kg of fish and each male was injected with 0.25ml/kg fish. Fish were injected Intramuscularly (IM) beside the dorsal fin.
On that day, we injected 9 pairs of Haruan. After injection, each fish was placed in the recovery tank and they were monitored to make sure that they recovered from the anesthesia and were actively swimming before moving onto the next fish. Aquatic plants like the water hyacinth were added into the tank to provide shade for the broodstock. When the females release the eggs, the eggs would adhere to the roots of the aquatic plants and be fertilised by sperm from the males. It was very important that each tank was covered securely as the Haruan are air breathers and are quite capable of escaping from the tanks and crawling overland for quite a distance. In fact, we lost one male during the night. It could not be found anywhere the next day. We suspect it crawled into the nearest drain and made its escape!
The next morning, farmers saw there were Haruan eggs stuck to the roots of the aquatic plants. Haruan fish are good parents and will take care of their eggs and young fry. However, both parents need to be given enough of food in order to prevent cannibalism.
The farmers are satisfied with the results when they found eggs had hatched into small fry with yolk sacs. The fry will use 3 days for the yolk to be fully absorbed. Once absorbed, farmers will start to feed the young fry and have to sort the fry according to size every 10 days. This is to avoid cannibalism among the fry.