Biocontrol of Oreochromis mossambicus Population by Chitala chitala (Hamilton, 1822) in a Composite Carp Culture System of Purulia District in West Bengal, India

Abstract

Aims: Pond-based carp production in the Purulia district in West Bengal, India is confronted with several challenges. This study aimed to establish an alternative semi-intensive carp production method for the district by addressing an endemic challenge i.e. recruitment of O. mossambicus, through an endangered (EN) and native predatory fish, Chitala chitala.
 Study Design: Present study has been conducted on two numbers of perennial water resources with 1 ha effective area; where annual production of Indian Major Carps (IMC) and impact of O. mossambicus and C. chitala on the same culture system have been compared.
 Place and Duration of Study: This study was conducted in farm conditions from 2018 to 2020, in two freshwater earthen ponds, Gosai Bundh (N23.47737/E86.79032) and Bara Notun Bundh (N23°46439/E86°65080), at Uluberia village under Kashipur Block of Purulia district in West Bengal, India.
 Methodology: Stocking density of Indian Major Carp (IMC) fingerlings was maintained at 8000 numbers (4:3:3 ratio of catla : rohu : mrigala) per ha (T1). After getting contaminated by O. mossambicus, wild C. chitala juveniles have been introduced in the similar facility (T2). Results of T1 and T2 were compared with control pond (C) containing IMC only. Recruitment of O. mossambicus and growth performance of C. chitala and IMCs determined periodically and annually.
 Results: Increasing growth of C. chitala showed contrasting impact over O. mossambicus fry recruitment. Survival percentage of C. chitala remains high in T2. While, poorest growth performance of IMCs have been observed in T1. Among IMC’s C. catla showed best survivality in every experimental ponds.
 Conclusion: Excessive recruitment of the O. mossambicus population can be controlled by C. chitala in a pond-based IMC culture system.