WELCOME

1. WELCOME

2. Integration of tilapia (Oreochromis niloticus) and sahar (Tor putitora) in carp polyculture Ramesh Jaiswal Madhav K Shrestha AquaFish CRSP

3. INTRODUCTION • Annual fish production: 3.3 t ha-1 (DOFD, 2010). • Semi-intensive carp polyculture is the major aquaculture system. • It is the mixed culture of common carp, silver carp, bighead carp, grass carp, rohu, naini and bhakur in certain ratio with stocking density of 7000 fish ha-1 • In most of the cases, number of species cultured ranges from four to six. • Sahar (Tor putitora) is high valued fish renounced for its taste and sports. • potential species for the aquaculture development.

4. Introduction……… • declining trend in total fish catches for sahar: Need for conservation • Incorporation into the existing carp polyculture system is one among various ways for conservation. • Nile tilapia (Oreochromis niloticus) is a lower trophic level species, commonly cultured in semi-intensive system. • Major constraints: inherently high recruitment. • Sahar was explored for its predation capacity on tilapia fries. • Addition of new species into the existing carp polyculture system may increase productivity and economic benefits.

5. STATEMENT OF PROBLEM • Need to improve existing carp polyculture system • Sahar population declining in natural habitat. Hence, it needs immediate attention for conservation • Nile tilapia has not reached to farmers on large scale because of prolific breeding behavior and risk to indigenous species in natural water. • Over recruitment in mixed sex tilapia culture needs to be controlled. • It can be controlled by co-culture with sahar. • Therefore, these 2 species needs to be incorporated into the carp polyculture system.

6. RATIONAL OF THE STUDY • Sahar : good candidate for aquaculture. • Its growth potential needs to be exploited for commercial culture. • over recruitment in tilapia culture: sahar helps to control recruitment. • Tilapia-sahar polyculture system has been established. • Carp-sahar polyculture is a useful tool for the conservation of this valuable indigenous species. • Integration of tilapia in carp polyculture provides opportunity to establish at farmers level. • Addition of these 2 species in carp polyculture may increase productivity and economic benefits.

7. OBJECTIVES • General objective • To assess the polyculture potentiality and compatibility of sahar and tilapia with carps under polyculture. • Specific Objectives • To assess the growth, production and productivity of carps, tilapia and sahar in different polyculture combinations; • To determine cost and benefits of fish production in each polyculture system; • To assess water quality produced by each polyculture treatment.

8. MATERIALS AND METHODS Facility &Location Twelve (12) earthen ponds, 110-150 m2 (average size: 130 m2) Fish farm, Department of Aquaculture, IAAS, Rampur Culture period From 25th February 2011 to 26th August 2011 for 180 days Test Species Sahar (Tor putitora) Nile Tilapia (Oreochromis niloticus) Silver carp (Hypophthalmichthys molitrix) Bighead carp (Aristichthys nobilis) Grass carp (Ctenopharyngodon idella) Common carp (Cyprinus carpio) Rohu (Labeo rohita) Naini (Cirrhinus mrigala)

9. Materials and Methods…… • Research Design: • Completely Randomized Design (CRD) • 4 Treatment and 3 Replication • Treatments were; • T1: Control: Existing carp polyculture system of Nepal • [Carps only (7000/ha)] • T2: Carps + Tilapia (3000/ha) • T3: Carps + Tilapia (3000/ha) + Sahar (500/ha) • T4: Carps + Tilapia (3000/ha) + Sahar (1000/ha) • silver carp, bighead carp, common carp, grass carp, rohu and naini were used in the ratio of 3:2:2.5:0.5:1:1 respectively.

10. Materials and Methods…… • Pond preparation • Ponds were completely drained and limed @ 500 kg lime/ha. • ponds were kept sun dried for 2-3 days after liming and then filled up with fresh water. • ponds were initially fertilized at the rate of 4 kg N and 1 kg P ha-1 d-1 using DAP and urea. • Water depth of about 1.0 m was maintained.

11. Materials and Methods…… • Procurement of the Research Material • Sahar fingerlings: Fisheries Research Centre, Pokhara. • Mixed-sex Nile tilapia, GIFT strain: Fisheries Research Center, Tarahara, Sunsari • Carp fingerlings: Department of Aquaculture-IAAS, FDC-Bhandara and Private hatcheries and nurseries. • Other materials (feed ingredients, lime, fertilizer, etc) : From local market

12. Materials and Methods…… • Stocking • Date: 25th February, 2011

13. Materials and Methods…… Table: Stocking number of experimental fishes in each treatment.

14. Materials and Methods…… • Pond Fertilization • Weekly fertilization @ 0.4 g N/m2/day and 0.1 g P/m2/day • DAP and urea was used @ 350 g and 470 g, for 100 m2 pond area.

15. Materials and Methods…… • Feeding • Supplemented with locally made pellet feed of about 20 % CP (Rice bran, maize flour, mustard oilcake and soybean oilcake in the ratio of 2:2:1:1). • Feed was offered once on alternate day @ 2 % of total estimated biomass of cultured fish. • Feeding tray was fixed in each pond and feed offered between 9-10 am. • Feed rations were adjusted monthly on the basis of sampling weights

16. Materials and Methods…… • Water quality measurement • wooden platform was constructed for feeding and water sampling. • Water samples were collected biweekly between 6.00-8.00 am using a plastic column sampler. • samples were analyzed for total alkalinity, total ammonium nitrogen (TAN), nitrite-nitrogen (NO2-N), soluble reactive phosphorous (SRP) and chlorophyll-a

17. Materials and Methods…… Table: Water quality parameters measured during experimental period.

18. Materials and Methods…… Proximate analysis of feed Proximate analysis of prepared feed was carried out to determine dry matter (DM), crude protein (CP), ether extract (EE), crude fibre (CF), total ash (TA) and nitrogen free extract (NFE) following the methods recommended in AOAC, 1980. • Fish sampling • At least 20-30% of the fish were netted for sampling and weighed to determine the growth. • Batch weight of sampled fish for each species from respective experimental pond was recorded. • Fish mortality was also recorded.

19. Materials and Methods…… • Harvesting • Date: 26th August, 2011 • Before complete drying of ponds, fishes as much as possible were netted out using a special type of net, locally known as paithijaal. • Harvested fishes were weighed using both physical and electronic balance. • Number of tilapia were counted and separated into two groups i.e. large and small based on size and their batch weight was taken. • Large size represented initially stocked tilapia and small size represented tilapia recruits produced in the pond.

20. Materials and Methods…… • Economic analysis • A simple economic analysis was conducted based on farm-gate prices for harvested fish and market prices for all costs in Nepal. • Farm gate prices of sahar, tilapia, carps were 300, 200 and 150-200 NRs kg-1, respectively. • Prices for sahar, tilapia and carps fingerlings were 5, 2 and 2 NRs piece-1, respectively. • Prices for feed, DAP and urea was 20, 45 and 30 NRs kg-1, respectively. • The calculation for cost of working capital was based on an annual interest rate of 10%.

21. Materials and Methods…… • Statistical analysis • Statistical analysis of data was performed by using one-way analysis of variance (ANOVA) using SPSS (version 16.0) statistical software package (SPSS Inc., Chicago). • Microsoft excel computer program was used for data tabulation and figure preparation. • Arcsine transformations were performed on percent data. • Regression analysis was done to determine growth trends for experimental fishes. • Difference among treatment means were determined by using LSD test. Differences were considered significant at the 95% confidence level (P < 0.05). • All means were given with ± standard error (S.E.).

22. RESULTS AND DISCUSSIONS Table : Proximate analysis of locally prepared pellet feed used in the experiment.

23. Table: Performance of tilapia and sahar. Data based on 100 m2 pond size. The daily weight gain of Nile tilapia was higher than grass carp-tilapia polyculture system (0.2-0.5 g) (Pandit et al., 2004), and similar with tilapia-sahar polyculture system (1.15 g) (Acharya et al., 2007) and (0.6-0.9 g) (Shrestha et al., 2011). Daily weight gain of sahar was similar to tilapia-sahar polyculture system (0.3-0.4 g d-1) (Shresthaet al., 2011) and lower than (0.55-0.77 g d-1) (Islam, 2002). The survival of sahar was lower than that reported by Acharya et al. (2007), but similar to Shresthaet al. (2011) (39-56%) in tilapia-sahar polyculture systems.

24. Figure: Growth trend of tilapia and sahar during the experimental period.

25. Table: Performance of silver carp and bighead carp. Data based on 100 m2 size. Daily weight gain for silver carp in all treatments was higher than 1.01±0.22 g d-1 reported by Pandey (2002). Similar daily weight gain of bighead carp, 1.02±0.13 g d-1, was reported by Pandey (2002).

26. Table: Performance of common carp and grass carp. Data based on 100 m2 size.

27. Table: Performance of rohu and naini. Data based on 100 m2 pond size.

28. Figure: Growth trend of carps during the experimental period.

29. Table: Overall Performance of carps. Data based on 100 m2 pond size. The gross carp yields (3.4 to 4.1 t ha-1 yr-1) was higher than the average productivity in Nepal (3.3 t ha-1 yr-1) (DOFD, 2010). Overall survival of carps was higher than 65% reported by Nepal et al. (2009), and lower than 91 to 100% reported by Pandey (2002).

30. Table: Combined performance of carps, tilapia and sahar. Data based on 100 m2 size.

31. Table: Tilapia recruitment from ponds (100 m2) during the experimental period. Tilapia recruits in carp-tilapia polyculture in this experiment (8.30 recruits m-2) were lower than 11 recruits m-2reported by Pandey (2002) from tilapia monoculture. Higher number of Nile tilapia recruits in carp-tilapia polyculture (T2) than in other polyculture treatments (T3 and T4) was probably due to absence of predatory Sahar in the carp-tilapia polyculture (T2) ponds (Acharya et al., 2007; Sharma, 2008).

32. Table: Overall mean and ranges of water quality parameters in each treatment. Figures in parentheses indicate ranges

33. Figure: Weekly mean temperature (oC) of pond water at 6.00–8.00 am in each treatment during the experimental period.

34. Figure: Weekly mean dissolved oxygen (mg L-1) of pond water at 6.00–8.00 am in each treatment during the experimental period.

35. Figure: Weekly mean Secchi depth (cm) of pond water at 6.00–8.00 am in each treatment during the experimental period.

36. Figure: Fortnightly measured mean soluble reactive phosphorous (SRP), Total ammonium nitrogen and nitrite nitrogen (mg L-1) of pond water at 6.00–8.00 am during the experimental period

37. Table: Comparative economic analysis (in NRs) for each treatment during the experiment. Mean values with same superscript in the same row are not significantly different (p<0.05).

38. SUMMARY AND CONCLUSION • This study was intended to incorporate tilapia and sahar into carp polyculture to improve production and productivity. • The present study clearly demonstrated that addition of Nile tilapia in the semi-intensive carp polyculture will increase the production (up to 57%) and net returns (up to 61%). • Similarly, addition of sahar resulted in less number of tilapia recruits, showing predatory nature of sahar to control tilapia recruits. • However, the addition of both tilapia and sahar to carps caused some water quality problems, especially depleting the DO concentration in the pond. • Thus it is necessary to fine-tune the ratio of carps, tilapia and sahar in polyculture. • This system provides an additional species for farmers. • Finally, further research on the improved survival and growth rate of sahar in carp polyculture is needed.

39. Thank you Queries are welcome !!!