GROWTH AND PRODUCTION PERFORMANCE OF AIR-BREATHING CLIMBING PERCH Anabas testudenius AND MAJOR CARPS IN POLYCULTURE

Shahroz Mahean Haque*, Askiur Rahman, Joythi Saha, TahminToma, Sadika Haque, Md. Abdul Wahab, Hillary Egna, and Russell J. Borski,
 
Email: Shahrozm2002@yahoo.com
Department of Fisheries Management, Bangladesh Agricultural University, Mymensingh, Bangladesh
 
Department of Agricultural Economics, Bangladesh Agricultural University, Mymensingh, Bangladesh
Department of Biology, North Carolina State University, Raleigh,
Oregon State University
 

The use of Koi or climbing perch (Anabas testudenius) in aquaculture has grown substantially over the past decade in Bangladesh because it has a high market value and is rich in nutrients. Further, being an air-breathing fish, Koi have a strong capacity to tolerate poor oxygen environments. Koi production is currently limited to monoculture systems with intensive use of commercial-grade feeds. Feed constitutes almost 80% of the total costs for producing Koi and thus methods to reduce feed inputs can provide significant economic benefits, particularly if fish are co-cultured with carps that rely primarily on natural pond productivity rather than direct consumption of formulated feeds. Thus, the aim of the present study was to investigate growth and production of Koi when used in polyculture with major Indian carp species, Rui (Labeo rohita) and Catla (Catla catla) relative to that observed in with monocultures. We also examined the effects of combining reduced feed ration and pond fertilization on Koi-carp polyculture.

The experiment consisted of four treatments, with three replicates each (12 ponds; 100 m2 area, 1.5 m depth). T1 consisted of a Koi monoculture (5/m2) with full daily feeding while the other three treatments consisted of a Koi-carp polyculture (Catla, 0.2/m2; Rui, 0.8/m2; Koi, 5/m2) with full daily feeding (T2), 75% daily feeding (T3), or 50% daily feeding (T4). Additionally, the ponds for T3 and T4 were fertilized weekly with urea and triple super phosphate (28 kg/ha N, 5.6 Kg P/ha) to boost pond productivity. Koi were fed a full daily ration of commercial feed (CP feed) according to current practice (20% down to 5% body weight/day) or a fraction of this based on treatment groups.

After 126 days, the average weight gains for Koi were 54.79, 96.63, 119.6 g, and 120.5g in T1-4, respectively. The body lengths for Koi were highest in T3 (18.22 cm), followed by T4 (17.97 cm), and lowest in T1 (9.5 cm). Average weights of Rui at the end of the study were 273, 298, and 340 g for T2-T4, respectively, while that for Catla was 456, 339 and 396 g for T2-T4, respectively. Survival of Koi ranged from 45 - 57% with the highest rate occurring in T4.  Catla and Rui survival was 67- 80% and 58 - 61%, respectively. The results demonstrate 1) that Koi growth is enhanced when polycultured with carps versus in monoculture, 2) addition of carps to Koi culture improves overall fish production over monoculture alone, and 3) reducing daily ration by 50% along with pond fertilization has little impact on growth of Koi or carps. Based on this research, Koi polyculture with carps is substantially more beneficial in terms of fish production than the current practice of Koi monoculture. This along with reductions in feed ration allow considerable improvement in feed conversion and cost savings with little impact on fish production.(Supported by the AquaFish Innovation Lab - USAID)