54 DECEMBER 2014 • WORLD AQUACULTURE • WWW.WAS.ORG during the 3-4 weeks of rearing indoors (Fig. 3). Fry rearing. Fry are further reared in cement tanks to fingerlings. Tanks may be prepared with a soil base and manured as in carp ponds to obtain a plankton bloom. Rearing tanks are filled with a minimum of 30 cm of water for easy visibility of fish activity. Fry show shoaling behavior and are active during feeding. Hence, a low density of 100-150/m2 is maintained to minimize competition and obtain homogenous growth and better survival (Sahoo et al. 2014). Fry are fed with crumbled feed containing 30 percent crude protein ad libitum, as visually indicated by satiation of fish. Filamentous algae grows in tanks because of the low water level and must be removed to avoid oxygen depletion and retarding swimming activity of fry. Survival is >60 percent and weight gain is > 500 mg and ≥ 60 percent during the 6-7 weeks of rearing. Fingerlings can be sold directly as ornamental fish at this stage or can be further reared in nursery tanks before grow-out (Fig. 4). Best Management Practices • Broodfish of > 100 g is necessary to induce spawning. • Broodfish can be reared by stocking at 1-2/m2 and feeding a 30-32 percent protein pelleted diet. Intermittent water exchange in broodfish pond enhances maturity for a better output of healthy eggs. • Injection of 1-1.5 mL Ovaprim/kg of female and stripping after 12-13 h of injection is sufficient to obtain good breeding performance and egg quality. • Larvae can be reared at a density of 500-1000/m2 for good growth within a short time, thereby enhancing survival. • Live feed should be provided during an initial rearing phase and larvae should be gradually weaned to the compound larval feed after 10-11 days of fertilization. This acclimation to feed stimulates fry to accept feed immediately after release into nursery tanks, which ultimately increases survival. Notes S.K. Sahoo, S. Ferosekhan, M. Paramanik, S. K. Swain, Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar 751 002, Orissa, India Corresponding author email: sksahoo100@rediffmail.com References Ali, P.H.A., R. Raghavan and G. Prasad. 2007. Threatened fishes of the world: Horabagrus brachysoma (Gunther, 1864) (Bagridae). Environmental Biology of Fishes 78:221-221. Bhat, A. 2001. New report of the species, Horabagrus brachysoma in the Uttarakhanda district of Karnataka. Journal of Bombay Natural History Society 98:294-296. Kurian, M and N.D. Inasu. 2003. Reproductive biology of a catfish Horabagrus brachysoma (Gunther) from inland waters of Kerala. Journal of Inland Fisheries Society of India 35:1-7. Kurup, B.M., K.V. Radhakrishnan and T.G. Manoj Kumar. 2004. Biodiversity status of fish inhabiting rivers of Kerala (S. India) with special reference to endemism, threats and conservation measures. Pages 163-182 In: R.L Welcomme and R.L. Peter, editors. Proceedings of the Second International Symposium on the Management of Large Rivers for Fisheries. Phnom Penh, Cambodia. Sahoo, S.K., S.S. Giri, S. Chandra and M. Paramanik. 2011. Management in seed production of an endangered catfish, Horabagrus brachysoma during its hatchery phase. Aquaculture Asia XVI(4):26-29. Sahoo, S.K., S.S. Giri, M. Paramanik and S. Ferosekhan. 2014. Preliminary observation on the induced breeding and hatchery rearing of an endangered catfish, Horabagrus brachysoma (Gunther). International Journal of Fisheries and Aquatic Studies 1:117-120 SreeRaj, N., R. Raghavan and G. Prasad. 2006. The diet of Horabagrus brachysoma (Gunther), an endangered bagrid catfish from Lake Vembanad (South India). Journal of Fish Biology 69:637-642. FIGURE 4. Fingerlings produced in nursery tanks before grow-out. FIGURE 3. Fry produced in high-density rearing during a 3-4 wk indoor rearing period.
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