Rainbow trout broodstock management and seed production in Turkey: Present practices, constraints and the future

Trout has been cultured in Turkey since early 1970s, but major developments took place during the 1990s. Currently, with an annual production over 40.000 tons, Turkey became one of the top trout producing countries. Although, production mainly comes from as portion size fish from freshwater farms, seafarming in the Black Sea provides around 2000 tons of large-trout. The paper describes the current rainbow trout seed production practices in Turkey and discusses areas of improvements.Lack of specialized broodstock or hatchery operators is one of the major characteristics of Turkish trout farming sector. Thus, most of the farms produce their own eggs and fry, and those have not got such facilities buy fingerlings rather than eyed-eggs, but demand for fingerlings vary considerably due to heavy losses as results of water quality fluctuations, disease outbreaks and management issues. There is no genetic breeding or selection programmes and described trout strains. Brood fish are mainly selected on morphological features and no records are kept. Age composition of the broodstocks range from 2 to 7 years, while the sex ratio is often around 1:1. Husbandry and feeding conditions of brood fish are very similar or sometimes worsen than on-growing fish. There is no off-season egg production through genetic or photoperiod manipulations, but natural egg production season ranges from November to April, peaking during January-February. Simply, eggs are stripped, fertilized with milt from at least two males and stocked into incubators of farm-made wooden-wire trays set in concrete or brick troughs, fiberglass troughs with aluminium baskets or vertical-flow stack incubators. Dead eggs are picked during the fist two days or after eyeing. Fluctuating water temperatures and suspended solids are main water quality related problems in hatcheries. Practices such as estimation of egg numbers, disinfections and shocking, and monosex or tripliod stock production are not common applications. Since the water temperature low or fluctuate widely incubation period lasts approximately 45 days and losses may reach 50 percent. Fry are fed commercial starter feeds with containing 45-50% crude protein. Feeding is performed by hand with 3-4 times daily only during the natural day length. Fry can be maintained indoor until size of 0.5-2.0 g and then moved out to small concrete raceways or fingerling ponds with some kind of shading. Growth rates vary widely between the farms and fry may reach mean size of 4-5 g 100 days after hatching. Disorders such as gas bubble, parasites (Ichthyobodo or Costia, Ichthyophthirius, -Saprolegnia) and diseases (Flavobacterium branchiophlla, Flexibacter columnaris, Yersinia ruckeri) may cause serious losses. Turkish rainbow trout sector has reached stage of maturation, but it has not utilized most of the biotechnological developments widely practices in northern countries. Thus, developments in seed production as specialization in seed production, selective breeding programmes, all year around egg supply, sterile stock production and recirculating systems can be exploited for further development.

Anahtar Kelimeler:

yumurta bırakmak, gökkuşağı alabalığı, larva, olgunlaşma, Türkiye

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Billard, R. and Jensen, J.O.T. 1996. Gamete removal, fertilization and incubation. W. Pennell and B.A. Bartons (Eds.), Principles of Salmonid Culture, Elsevier Developments in Aquaculture and Fisheries Science, 29, Amsterdam: 291-364.

Bromage, N.R. 1988. Propagation and stock improvement. C.J. Sherpherd and N.R. Bromage (Eds.), Intensive Fish Farming, BSP Professional Books, Oxford: 103- 153.

Bromage, N.R. 1995. Broodstock management and seed quality – general considerations. N.R. Bromage and R.J. Roberts (Eds.), Broodstock Management and Egg and Larval Quality. Blackwell Science, Oxford: 1-24.

Bromage, N.R. and Cumaranatunga, P.R.C. 1988. Egg Production in the Rainbow Trout, In: R.J. Roberts and J.F. Muir (Eds.), Recent Advances in Aquaculture Vol. 3. Croom Helm., London: 63-138.

Bromage, N.R., Shepherd, J. and Roberts, J. 1988. Farming systems and husbandry practice. C.J. Sherpherd and N.R. Bromage (Eds.), Intensive Fish Farming, BSP Professional Books, Oxford: 50-102.

Bromage, N. R., Jones, J., Randall, C., Thrush, M., Davies, B., Springate, J., Duston, J., and Barker, G. 1992. Broodstock management, fecundity, egg quality and timing of egg production in the rainbow trout (Oncorhynchus mykiss). Aquaculture 100: 141–166.

Çelikkale, M.S., Düzgüneş, E. and Okumuş, İ. 1999. Türkiye Su Ürünleri Sektörü: Potanisyeli, Mevcut Durumu, Sorunları ve Çözüm Önerileri. İTO Yayınları, No: 1999-2, İstanbul. 414 pp.

DIE, 2000. 1999 Yılı Su Ürünleri İstatistikleri. T.C. Devlet İstatistik Enstitüsü, Ankara.

DIE, 1999. 1998 Yılı Su Ürünleri İstatistikleri. T.C. Devlet İstatistik Enstitüsü , Ankara.

EIFAC (FAO) - HAKI. 1999. Regional Review on Trends in Aquaculture Development – Europe. Rome. 237 pp

Gall, G. A. E. and Crandell, P. A. 1992. The rainbow trout. Aquaculture, 100: 1-10.

Gjerde, B. 2001. Personnel communications.

Gjerdem, T. 1992. Breeding plans for rainbow trout. Aquaculture, 100:73-83.

Ingram, M. 1988. Farming rainbow trout in freshwater tanks and ponds. L.M. Laird and T. Needham (Eds.), Salmon and Trout Farming. Ellis Horwood, Chichester: 155-189.

Kurtoğlu, İ.Z., Okumuş, İ. ve Çelikkale, M.S. 1998. Doğu Karadeniz Bölgesi’nde ticari bir işletmedeki gökkuşağı alabalığı (Oncorhynchus mykiss) anaçlarının döl verim özellikleri ve yavrularının büyüme performanslarının belirlenmesi. Turkish Journal of Veterinary and Animal Sciences, 22 (6): 489-496.

Laird, L.M. and Needham, T. 1988. The farmed salmonids. In: L.M. Laird and T. Needham (Eds.), Salmon and Trout Farming. Ellis Horwood, Chichester: 15-31.

Lem, A. 1999. Presentation given at the Conference on Aquaculture, Economics and Marketing Debrecen, Hungary, 30 August - 1 September 1999. http://www.globefish.org/presentations, accessed in November 2001.

MacCrimmon, H.R. 1971. World distribution of rainbow trout (Salmo gairdneri). J. Fish. Res. Board Can., 28: 663-704.

Morrison, J.K. and Smith, C.E. 1986. Altering the spawning cycle of rainbow trout by manipulating water temperature. Prog. Fish. Cult., 48: 52-54.

Needham, T. 1988. Sea water cage culture of salmonids. L.M. Laird and T. Needham (Eds.), Salmon and Trout Farming. Ellis Horwood, Chichester: 117-154.

Okumuş, İ., Üstündağ, C., Kurtoğlu, İ.Z. ve Başçınar, N. 1997. Deniz kafesleri ve tatlısu havuzlarında stoklanan gökkuşağı alabalığı (Oncorhynchus mykiss) anaçlarının sağım zamanı, yumurta verimi ve kalite özellikleri. IX. Ulusal Su Ürünleri Sempozyumu, 17- 19 Eylül 1997, Eğirdir.

Pepper, V.A. and Crim, L.W. 1996. Broodstock Management. W. Pennell and B.A. Bartons (Eds.), Principles of Salmonid Culture, Elsevier Developments in Aquaculture and Fisheries Science, 29, Amsterdam: 231-289.

Piper, C.E., McElwain, I.B., Orme, L.E., McCraren, J.P., Fowler, L.G. and Leonard, J.R. 1982. Fish Hatchery Management. U.S. Fish and Wildlife Service, Washington, D.C., 517 pp.

Stockard, L.J. 2001. Chile fishery products: market access restored for U.S. Salmonid Eggs. US USDA Foreign Agricultural Service, GAIN Report #CI1009. http://www.fas.usda.gov/gainfiles/200102/, accessed in November 2001. Springate, J.R.C. and Bromage, N.R. 1983. Egg production and broodstock management. Fish Farmer, 6:21.

Ulupınar, M. and Okumuş, İ. 1999. An investigation on the chromosome structure of rainbow trout (Oncorhynchus mykiss) in a commercial farm in Turkey. M.S. Çelikkale, E. Düzgüneş, İ. Okumuş and C. Mutlu (Eds.), FISHECO’98: Proceedings of the First International Symposium on Fisheries and Ecology, 2-4 Sep. 1998, Trabzon, Turkey : 183-190.

Tacon, A.G.J. 1998. International Aqua Feed Directory and Buyer’s Guide 1997/98, Turret Rai PLC. Middlesex, U.K.