By Amod Ashok Salgaonkar
India – ICAR-Central institute of Brackishwater Aquaculture, Chennai functioning under the aegis of Indian Council of Agricultural Research has produced grey mullet (Mugil cephalus) fry in captivity for the first time in the country. Grey mullets are commonly called “Madavai” in Tamil, “Thirutha” in Malayalam, “Kathiparega or Mala” in Telugu.
Grey mullets are distributed in tropical and sub-tropical waters, including the Indian subcontinent. Being euryhaline grey mullets are found in freshwater, brackishwater and marine habitats, belongs to the family Mugilidae, and is the fastest growing species among Mullets. These vegetarian fish are omnivorous and feed primarily on detritus and benthic micro-algae, are efficient converters of primary productivity into quality fish protein. Due to the texture, taste and free of spines, consumer preference is high, and fetches good market price, which is in the range of Rs. 350 to Rs. 500/kg. Fast growth rates and omnivorous feeding habit, acceptance of formulated pellet feed makes it a preferred fish of brackishwater aquafarmers. It is an ideal candidate species for polyculture and Integrated Multitrophic Aquaculture systems. A production upto 3.5-4 tonns per ha/crop can be achieved at a benefit cost ratio of about 1.9.
Captive reproduction of grey mullet was first reported in Taiwan in 1960’s, thereafter Hawaii, the United States of America, the Israel, Italy, Egypt and Abu-Dhabi have achieved fry production on experimental scale.
Indian R&D efforts on Captive Breeding, and successful breeding breakthrough by ICAR-CIBA, 2016-2020
In India, attempts to develop captive breeding technology for grey mullet were initiated in 1980’s, where maturation and breeding has not been successful, and it remained as a challenge. One of the primary reasons which makes the captive breeding of the species extremely challenging, is related to its short annual reproductive period limited to few weeks during monsoon and reproductive dysfunctions in captivity. One time breeding character further contributed to the efforts in breeding.
In India, the reproductive period of captive grey mullet is July in the south-west coast and November in south-east coast, related to monsoon showers, low water temperature. Considering its significance in brackishwater aquaculture, CIBA has given greater impetus in the breeding of grey mullet since 2015, giving special focus on developing a captive broodstock and breeding. As a result of these efforts, successful breeding and larval production of M. cephalus was achieved using pond reared broodstock in 2016-17. This season by Decemeber-January, CIBA has completed producing its third batch of hatchery reared grey mullet fingerlings. Formulation of indigenous pellet feeds for the broodstock, larvae, nursery and growout feeds has contributed for the present success in developing the indigenous hatchery technology.
Hatchery produced grey mullet seeds to fish farmers
Hence, at this opportune moment hatchery produced grey mullet seeds are being handed over to potential enterprising farmers, from Ap, TN and Kerala. The seeds will be raised in their respective farms and developed into F1 broodstock, which would be bought back to CIBA hatchery for further breeding and seed production. These initiatives towards species domestication may make a wider breeding window of grey mullet available and the process of induced maturation less challenging. Presently, CIBA has already standardised seed production of brackishwater food fish species; Asian seabass, milkfish, pearlspot, whiskered cat fish, and also ornamental species as spotted spotted scat, moon fish, orange chromide. CIBA looks forwards towards scaling up of grey mullet seed production in partnership with enterprising farmers and state governments as we take another step towards a diversified and sustainable brackishwater aquaculture sector. Representative from the industry, aquafarmers, fisheries scientists have welcomed the breakthrough, as another sought after farmed fish, which can be farmed in brackishwater, freshwater and marine has been added to Indian aquaculture species basket.
On this occasion a function was held on 28th January 2021 at Muttutukadu Experimental Station, ICAR-CIBA for distribution of first batch of hatchery produced grey mullet seeds and species-specific functional feed, Cephalusplus to enterprising farmers. The function was graced by dignitaries and farmers from the aquaculture sector. Dr J.K. Jena, DDG (Fy.) ICAR presided over the function and congratulated team CIBA on the milestone. He said that mullet has always been a cherished fish and historically a part of brackishwater aquaculture and amenable for farming in different culture systems and salinity. He also mentioned that the present form of brackishwater farming which is largely dominated by single shrimp species and CIBA ‘s recent efforts towrads species diversification with species such as Asian seabass, milkfish, grey mullet is fundamental for the sustainable development of the sector. He encouraged the research team to transfer the technology to stakeholders along with establishment of brood-banks under PMMSY scheme with fisheries departments, NGO’s, NFDB and entrepreneurs.
Delivering the presidential address, Dr. K.K. Vijayan, Director, ICAR-CIBA emphasized that finfish breeding technology required scientific backstopping in form of breeding biotechnology, feed development, fish health support and those helped to close the life cycle of grey mullet after decades of research. Dr. K.K. Vijayan highlighted the importance of raising hatchery bred grey mullet juveniles into F1 broodstock to counter the biological challenge of single narrow breeding window. This is one of the main stumbling blocks in the path towards grey mullet hatchery production.
Welcoming the gathering Dr. M. Kailasam, Principal Scientist and Head-in-charge Finfish culture division stressed that grey mullet farming is remunerative because of high demand in domestic market. CIBA’s initiatives and breeding technologies has led to introduction one more candidate species for brackishwater aquaculture diversification and sustainability.
Hatchery produced grey mullet seeds were distributed to farmers from Tamil Nadu, Kerala and Andhra Pradesh. Farmers expressed their interest for grey mullet farming as the fish can grow 500 – 600 g in 5-6 months of culture period and fetch a market price of Rs 300-400/kg. Domestic market for this fish is also very promising due to unique texture and white meat. Farmers expressed their interest to get the hatchery produced seed for develop them as broodstock for CIBA in the coming years. Dr. M. Vijayakumaran, member of research advisory committee of CIBA stressed on importance of pond health for higher productivity in dynamic brackishwater aquaculture systems. The importance of quality feed to improve feed conversion ratio and pond environment was emphasized by Mr. Ramachandra Raju, Institute Management Committee member, ICAR-CIBA. Mr. S. Sathish Kumar, Institute management council member expressed hope that grey mullet farming can be customised to suit small and marginal farmers as livelihood activity. Mrs. Rachael Deputy Director, Mariculture, Department of Fisheries, Tamil Nadu, appreciated CIBA’s effort to develop new technologies for seed production and species-specific feed development for grey mullet. Dr. N. Kalaimani, executive member SCAFI said that though the breeding of grey mullet was attempted in the previous years but hatchery produced seed has been given to the farmer for first time. Speaking on the occasion, Dr. K. Ambasankar, SIC, nutrition group stated that CIBA has developed larval, nursery, grow out and broodstock diets for grey mullet farming. Earlier hatchery produced grey mullet seed were handed over to progressive farmers from Kerala, Mr. A.M. Nizar and Mr. Purushothaman Thayambath; Andhra Pradesh, Mr. T. Raghu Shekhar; Tamil Nadu, Mr. M. Sathya and they flagged the importance of polyculture of herbivorous fish species like grey mullet and milkfish and need for multi-species private finfish hatcheries in brackishwater aquaculture sector.
