Date of Publish: 15 October, 2016
Kishore Talukdar –
A new method of artificially breeding the popular fresh water fish is being tried out in Assam–
Magur (Clarias batrachus), or Asian cat fish, is often associated with the traditional methods of fishing in Assam– done with a jakoi (hand-held bamboo fishing net). Especially because jakois are typically used in shallow natural water bodies– the habitat of the Magur. This fish species prefers living inside hole in soil bed which also helps them to protect themselves. It is a nocturnal fish species.
Dishes made of this fresh water fish are an important part of traditional Assamese cuisine. It is a fish celebrated both for its taste and nutritional value.
However, for some time, the chances of finding a Magur in a local fish market have gone down by the day. Success rate of artificial breeding is not to desired level. So is the crisis of the seed till now to meet the rising demand.
The scenario may see a change in coming times. Thanks to the success of an innovative breeding technology.
As per the state Fisheries Department, an officer has made a breakthrough by successfully conducting captive breeding of Magur without striping.
Usually, seed of this fish species is produced by using synthetic hormone thorough the stripping method. However, Raben Das, a Fishery Extension Officer, has bred the species in confined waters without stripping.
As per Das, induced breeding of Magur can be done by using a single dose of synthetic hormones in both the male and female fish, depending upon the climatic condition. After injecting the hormone, both male and female fish are to be released in a breeding tank (cemented, in the size of 3ft x 2ft x 3ft size where water depth should not be more than 1 feet). Within 24 hours, the females release eggs in the water. Simultaneously, the male fish releases the sperm over the eggs. Immediately after it, both the male and female fish need to be taken out of the breeding tank.
One female Magur can lay up to 3000 to 5000 eggs. Vigorous aeration is essential to supply artificial oxygen in to the water of the breeding tank, but care should also be taken to avoid rapture of the eggs. The fertilized eggs are adhesive in nature and orange in colour which eventually turn into light brown — after a few hours. From the fertilization point of view, eggs light brown in colour are deemed good, unlike the ones that are of white colour. Within 24 to 26 hours hatching takes place. The newly hatched larvae require 3 to 4 days to absorb their yolksac. And they start taking live feed.
Das successfully conducted the breeding operation in 2013 by using four pairs of Magur fish. In 2016, he used 10 pairs in the breeding operation. Farmers from Morigaon, Barpeta, Darang and Kamrup districts have already purchased the seeds produced from the latest excercise.
Unlike in the stripping method, the male fish doesn’t have to pay their life in this new method. In the stripping method, eggs are fertilized artificially with sperm suspension where it is difficult to save the lives of the male and female brooders. Round the clock monitoring of water temperature, oxygen level, water flow and quality, feeding and nursery management are imperative in the stripping technology.
Das tells nezine.com that production of seed of the Clarias batrachus (the scientific name of Magur) without stripping is easier and economical in comparison. He points out that the specialty of this breeding technique is that there is no need to sacrifice the brooders for breeding.
“Survival of seed is better in this technology than in the existing one,” Das claims. Drawing a comparison between the existing technology and the one he has devised, he says the brooders can now be reused for breeding after a year.
Successful seed production of Clarias batrachus depends upon the maintenance of the healthy brood fish. Usually, this species attains maturity in the second year and a fish of 100 to 150 gm is considered suitable for breeding. Small earthen ponds suits fine to rear the brooders for harvesting in the rainy season.
Phatik Ahmed, a progressive farmer from Barpeta, purchased 1000 spawns in July this year from Das, who bred spawns by the new technology and is growing them in his fish farm presently. Also an expert in ornamental fish breeding and rearing, Das has worked in an ornamental fish breeding farm under the guidance of Israeli consultant Joshep Itzchovic.
As per Ahmed, the latest method of producing seeds is much easier than the existing one and he will start producing Magur spawns by using it himself from the next year.
Says Ahmed, “Farmers should come forward to cash in on the huge commercial prospects of Magur fish culture, given the skyrocketing price of Rs 800 to Rs 1200 of the fish per kg.” He attributes the dwindling population of the fish to growing application of chemical fertilizers in cultivation.
Magur is an air breathing cat fish species. Having high grade protein (15 percent), high concentration of iron (710 mg/100g) tissue and low fat (1.0 percent), it is often called a medicinal fish. With tremendous health benefit, it is a boon to the pregnant and lactating mothers, the elderly and children in need of extra nutrition.
Title Picture: Kishore Talukdar