Comparative effect of live food and manured treatments on water quality and production of ornamental carp, Cyprinus carpio var. koi L., during winter, summer, monsoon and post-monsoon growout experiments in concrete tanks

Authors: Jha, P.1; Barat, S.1; Sarkar, K.2

Journal of Applied Ichthyology, Volume 23, Number 1, February 2007 , pp. 87-92(6)

Abstract:
Summary

Four growth trials (each of 11?weeks duration) were conducted during different seasons throughout 1?year, namely, winter, summer, monsoon and post-monsoon to assess the seasonal influence on growth and production of koi carp, Cyprinus carpio var. koi L. larvae in concrete tanks maintained under different management regimes. Individual weight gain, survival rate, fish deformities and number of marketable fish in each season were compared among four management regimes: (i) carp larvae fed with live zooplankton (LF); (ii) direct fertilization with poultry manure (PM); (iii) direct fertilization with cow dung (CD); and (iv) a control system (C), where a commercial diet containing 32% crude protein was applied. There were three replicates for each treatment. The LF treatment produced significantly higher weight gain, survival rate and number of marketable fish in all seasons (P?<?0.05), compared with the other treatments, through maintenance of better water quality and greater abundance of zooplankton in the system. Fish deformities were highest in the C treatment in every season (P?<?0.05). Water temperatures averaged 18.6°C (winter), 29.7°C (summer), 28.3°C (monsoon), and 26.5°C in the post-monsoon trial. Average weight gain of koi carp achieved during the winter trial (2.01?g in C to 4.44?g in LF) was considerably lower than that achieved in the summer, monsoon or post-monsoon trials. Survival rates of carp ranged from 70.5% (C) to 95.5% (LF) in the winter trial, and were considerably lower than the other seasons. The number of marketable fish was also lowest during the winter trial.

*Aquaculture and Limnology Laboratory, Department of Zoology, University of North Bengal, Siliguri, West Bengal, India; 2: Rainbow Ornamentals, Raninagar, Jalpaiguri, West Bengal, India