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International Journal of Pure & Applied Bioscience (IJPAB)
Year : 2018, Volume : 6, Issue : 6
First page : (33) Last page : (42)
Article doi: : http://dx.doi.org/10.18782/2320-7051.7119

Egg Hatchability and Larval Viability of Labeo rajasthanicus in Relation to Water Hardness

Vijay Kumar², V. P. Saini¹*, M. L. Ojha² and Surnar Sharad Raosaheb¹

¹Aquaculture Research and Seed Unit, Directorate of Research,
²Department of Aquaculture, College of Fisheries
Maharana Pratap University of Agriculture and Technology, Udaipur - 313001 India
*Corresponding Author E-mail: sainivpfish@yahoo.com
Received: 26.10.2018  |  Revised: 29.11.2018   |  Accepted: 6.12.2018

 ABSTRACT

This study was conducted to assess the impact of water hardness on egg hatchability and larval viability of Labeo rajasthanicus. For this purpose, five hardness levels were tested [200(T1), 175(T2), 150(T3), 125(T4) & 100(T5) mg/l ] in relation to fertilization rate, ova diameter, hatching duration, hatching per cent and hatchling survival of Labeo rajasthanicus. In each hatchery jar of two liters capacity, 5000 eggs ware incubation & each treatment was run in triplicate. The smallest (3.33 mm) ova diameter was observed in T1, whereas the biggest (3.54 mm) ova diameter was in lowest water hardness level (T5). The Minimum hatching time (15.45 hrs.) was noticed in lowest hardness treatments (T5), which was significantly increased with increasing hardness level and the highest hatching time was recorded in highest (200 mg/l) concentration of hardness. The highest hatching rates (95%) occurred in groups of eggs that were hardened in the softest water treatment (100 mg/l), whereas the lowest hatching rates (69%) was in (T1). The highest larval survival (79.46%) was recorded in 200 mg/l water hardness and lowest larval survival rate (65.71%) was found in 100 mg/l hardness. Further, the survival rate had positive relationship with hardness as the rate of larval survival significantly increased with increasing water hardness. Further, the second order polynomial regression analysis between water hardness and breeding indices (Fertilization rate, ova diameter, hatching rate & larval survival) indicated that a water hardness of 125 mg/l is most suitable for Labeo rajasthanicus breeding.

Key words: Fertilization, Hardness, Hatching, Labeo rajasthanicus, Ova, Survival

Full Text : PDF; Journal doi : http://dx.doi.org/10.18782

Cite this article: Kumar, V., Saini, V.P., Ojha. M.L. and Raosaheb, S.S., Egg Hatchability and Larval Viability of Labeo rajasthanicus in Relation to Water Hardness, Int. J. Pure App. Biosci.6(6): 33-42 (2018). doi: http://dx.doi.org/10.18782/2320-7051.7119