COURSE MANUAL on Marine Fisheries & Mariculture Prepared for the Training programme for B.F.Sc students of Central Agricultural University (CAU), Tripura February, 2020 Course conveners Dr. R. Jayakumar., Principal Scientist & Scientist-in- Charge, Dr. V.P. Vipinkumar., Principal Scientist & ATIC Manager, Dr. Johnson, B., Scientist, Shri. M. Sankar, Scientist. ICAR - Central Marine Fisheries Research Institute (Indian Council of Agricultural Research) Mandapam Regional Centre in collaboration with Agricultural Technology Information Centre (ATIC). PREFACE The undergraduate Fisheries Science students are required to know about the inland and marine fisheries. The students from landlocked area are getting rare opportunity to understand the marine fisheries and mariculture activities. Hence, based on the request of the Central Agricultural University (CAU), Tripura as a part of their academic activities, the Director, ICAR-CMFRI, has kindly approved a 10 days in-plant training for B.F.Sc. final year students at the ICAR-Central Marine Fisheries Research Institute (CMFRI), Mandapam Regional Centre. The training was organized in collaboration with Agricultural Technology Information Centre (ATIC), ICAR-CMFRI, Kochi. A total of 27 B.F.Sc students and a faculty of Central Agricultural University (CAU), Tripura participated in the training programme during 17th to 26th January, 2020. The training emphasized on the skill development of students through hands on training on mariculture activities and field visits to fish landing centres. A course manual was prepared covering the major topics on marine capture fisheries and mariculture. I congratulate all those who have put in their sincere efforts to bring out this manual. Dr. R. Jayakumar Principal Scientist & Scientist-in- Charge Mandapam Regional Centre CONTENTS 1. Marine finfish breeding and seed production with special reference 1 to cobia and silver pompano 2. Fish Reproduction, Reproductive dysfunctions in captivity and 7 Hormonal Induction of Spawning 3. Larviculture of Cobia and Silver Pompano 11 4. Microalgae as live feed 18 5. Rotifers as live feed 38 6. Artemia – The global live feed for aquaculture 54 7. Farming of cobia and silver pompano 59 8. Marine ornamental fish seed production 68 9. Stock enhancement of shrimp resources through sea ranching 75 10. Seaweed Farming and Integrated Multi-Trophic Aquaculture 82 (IMTA) 11. Fish Population Genetics and Management of Captive Breeding 88 Populations 12. Marine biodiversity and its conservation methods in Gulf of Mannar 100 and Palk Bay 13. An overview on commercially important pelagic fishery resources of 109 gulf of mannar and palkbay 14. Demersal fishes of Gulf of Mannar and Palk Bay 116 15. Taxonomy and Biology of commercially important Species of 124 Shrimps, Crabs and Lobsters 16. Seagrass, seaweed and mangrove ecosystem of gulf of mannar and 129 palk bay region CONTENTS 1. Marine finfish breeding and seed production with special reference 1 to cobia and silver pompano 2. Fish Reproduction, Reproductive dysfunctions in captivity and 7 Hormonal Induction of Spawning 3. Larviculture of Cobia and Silver Pompano 11 4. Microalgae as live feed 18 5. Rotifers as live feed 38 6. Artemia – The global live feed for aquaculture 54 7. Farming of cobia and silver pompano 59 8. Marine ornamental fish seed production 68 9. Stock enhancement of shrimp resources through sea ranching 75 10. Seaweed Farming and Integrated Multi-Trophic Aquaculture 82 (IMTA) 11. Fish Population Genetics and Management of Captive Breeding 88 Populations 12. Marine biodiversity and its conservation methods in Gulf of Mannar 100 and Palk Bay 13. An overview on commercially important pelagic fishery resources of 109 gulf of mannar and palkbay 14. Demersal fishes of Gulf of Mannar and Palk Bay 116 15. Taxonomy and Biology of commercially important Species of 124 Shrimps, Crabs and Lobsters 16. Seagrass, seaweed and mangrove ecosystem of gulf of mannar and 129 palk bay region MARINE FINFISH BREEDING AND SEED PRODUCTION WITH SPECIAL REFERENCE TO COBIA AND SILVER POMPANO G. Tamilmani,A.K. Abdul Nazar, R. Jayakumar, M. Sakthivel, P. Rameshkumar, K.K. Anikuttan, and M. Sankar Mariculture Division, MRC of CMFRI, Mandapam Camp, Tamil Nadu Introduction Since many centuries mankind grows almost all its food on cultivated farm land,as far as this food consists of terrestrial plants and animals.But, when it comes to sea water plants and animals, modern man still continues to collect them from natural sources like his forefathers. Marine animals have always been and still are an important source of protein and minerals in human food. With the rapid increase in human population the demand for sea food will certainly increase. However, production from capture fisheries has stagnated and fisheries cannot expand much further. Further increase in exploitation of the seas will lead to destruction of ecosystems and species extinction. Mariculture - the farming and husbandry of marine plants and animals can augment the marine fish production and can supplement the capture fisheries. One of the major requirements for the establishment of a sustainable mariculture industry is the availability of quality seeds. Seed collection from the wild is unpredictable and cannot be relied upon. The ability to produce viable offspring from captive brood stock can ensure a steady supply of seeds. Countries like Australia, China, Indonesia, Japan, Malaysia, Philippines, Taiwan, Thailand and Vietnam have made substantial progress in the development of commercial level seed production technologies of high value finfish suitable for sea farming. In India, the commercial mariculture industry for finfish is in its infancy and the primary technological bottleneck is the lack of commercial-scale hatchery technologies for targeted species.The ICAR –CMFRI is addressing the problem of seed availability through its research on breeding and seed production of several marine species. To date, technologies for breeding and seed production of cobia (Rachycentroncanadum), silver pompano (Trachinotusblochii), orange spotted grouper (Epinepheluscoioides), Indian pompano (Trachinotusmookalee) and pink ear emperor (Lethrinuslentjan) have been developed and are being refined continuously to make them commercially viable. With the expanding interest in aquaculture and the market demand for more diversified species hatchery technology is being developed for an increasing number of species. This chapter aims at giving a general view of the major steps involved in marine finfish breeding and seed production with special emphasis on cobia and silver pompano. Broodstock Collection and handling It is not easy to obtain fully mature broodstock fish directly from the wild and hence broodstock development has to be done in captivity. Fish broodstock may be collected from the wild or captive stock. It is advantageous to collect sub-adults for broodstock development. Larger fishes would have crossed the reproductive age and very small fishes will take longer time to sexually mature. In the case of cobia, fish weighing between 8 to 15 kg could be procured while silver pompano could be procured in weight range of 750 gm to 1.5 kg. Cobia and silver pompano does not have swim bladder as juveniles or adults, and there is no need to vent the fish after capture Page No. 1 Stress should be minimised during capture and handling of broodstock. It is best to collect broodstock fishes from hook & line and trap nets, as they cause minimum stress to the fishes. During transportation, dissolved Oxygen (DO) should be maintained at or above saturation. For handling and transfer, fish are anesthetized with 10-20 ppm clove oil (Aqui- S). Once anesthetized, the fish can be weighed, measured, tagged, sexed and sampled for assessment of sexual maturity. On arrival at the hatchery prophylactic treatment is given to the fishes to reduce the risk of introducing ectoparasites or bacterial diseases into the hatchery facility. Formalin bath (100 ppm) for 2-5min followed by freshwater bath for 5-10 min is normally given. Silver pompano has a high tolerance for freshwater and freshwater bath can be given for more than 15 minutes also without any problem. During the treatment, fishes should be closely monitored. If the fishes suddenly become immobile or if their opercular movements become very slow or if the fishes are turning upside down, they should be immediately transferred to filtered seawater. Broodstock Development The basis for any hatchery operation is the maintenance of a healthy group of sexually mature fish (brooders) conditioned to spawn naturally or in response to hormonal induction. Broodstock development is the vital and time consuming procedure in marine finfish seed production.Good broodstock management involves providing close to natural, non-stressful environmental conditions as well as a nutritious and balanced diet. Generally, broodstock development of marine finfish is being practiced either in sea cages or land-based cement concrete or fibre-reinforced plastic (FRP) tanks.Broodstock developed in sea cages are susceptible to changes in the water quality of the cage site, disease problems and impact of harmful algal blooms. Therefore, the broodstock developed in sea cages are not bio-secure. In land based broodstock development systems, continuous flow through is provided with 300-500 % of water exchange for maintaining the water quality. This involves huge expenditure. Further,this exposes the broodstock to varying water quality