Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Impact of Freshwater Prawn and Tilapia Culture on Benthos in Periphyton Facilitated Ponds

M.N. Hasan
Bangladesh Fisheries Research Institute, Shrimp Research Station, Bagerhat

M.A. Bashar
Bangladesh Fisheries Research Institute, Shrimp Research Station, Bagerhat

M.F. Siddique
Bangladesh Fisheries Research Institute, Shrimp Research Station, Bagerhat

M.A. Forhad
Department of Fisheries Management, Bangladesh Agricultural University, Mymensingh

M.S. Rahman
Department of Fisheries Management, Bangladesh Agricultural University, Mymensingh

Abstract/ Executive Summary:

An experiment was carried out to evaluate the effect of addition of tilapia on abundance of benthos in freshwater prawn (Macrobrachium rosenbergii) (de Man) culture system for a period of 120 days at Fisheries Field Laboratory Complex, Bangladesh Agricultural University, Mymensingh. A long pond (83×8.9 m) was drained completely and partitioned by galvanized iron sheet into 18 small ponds of 40 m2 each, of which 6 ponds were used for this experiment. The experimental ponds were divided into 2 treatments each with 3 randomly selected ponds. The absence and presence (0 and 0.5 individual m²) of tilapia were investigated in 40 m2 ponds stocked with 3 prawn Juveniles (5±0.04 g) m^-2 with added substrates for periphyton development. A locally formulated and prepared feed containing 30% protein was supplied considering the body weight of prawn only. Feeds were supplied twice daily and feeding rates were at a rate of 10% of body weight for 1st month, 7% of the body weight for 2nd month and 3% of the body weight for the rest of the culture period. Benthic organisms had no significant difference (p>0.05) between the treatments.

Keywords: Benthos, Freshwater prawn, Tilapia

Location: Fisheries Field Laboratory Complex of the Faculty of Fisheries, Bangladesh Agricultural University, Mymensingh

Start Date: 20-02-2008

End Date: 20-06-2008

Program Area: Farming System

Commodity: Tilapia, Prawn

Objectives:

1. To estimate the abundance of benthic population of the experimental ponds both qualitatively and quantitatively and to determine the suitability of benthic organism as feed to popularize prawn and tilapia culture as homestead enterprises for rural people.

Methodology:

Study area and pond facilities: The experiment was conducted in 6 earthen ponds each of which was 40m² in the Fisheries Field Laboratory Complex of the Faculty of Fisheries, Bangladesh Agricultural University, Mymensingh, for a period of 120 days from 20 February to 20 June 2008. The ponds were rectangular in shape, well exposed to sun light, independent, and having water supply facilities. The water depth was maintained to a maximum of 1m over the study period. The surrounding of all ponds was covered by 1m height nylon net to prevent the entry of predators like snakes, frog and others. Experimental design: The experimental design was CRD (completely randomised design). There were two treatments: treatments PT0 and treatment PT0.5, each treatment with three replications. Pond preparation: All undesirable fish were completely eradicated by applying rotenone at a rate of 2.5 gm^-3. Aquatic weeds were removed manually. The grasses of the pond dikes were also cut into small size by using scythe. Lime (CaO) was applied at a rate of 250 kg ha^-1 after one week of rotenone application. Lime was dissolved in water in an earthen pot and then applied by spreading homogenously in the ponds. Ponds were fertilized with urea and triple super phosphate (TSP) each at a rate of 25 kg ha-1 and cow dung at a rate of 1000 kg ha^-1 after three days of liming. TSP was applied after dissolving in plastic buckets for 10 to 12 hours before application. Fertilizers were applied by spreading methods. The shelter was built by bamboo kanchi with date tree leaves. Shelter was installed in each pond before prawn juveniles stocking to provide shelter for prawn. About 436 bamboo (locally known as kanchi) with a mean diameter of 0.05 m were posted vertically into the bottom mud of each ponds, excluding a one meter wide perimeter water surface from the dike. This resulted in an additional area for periphyton development equaling about 60% (i.e.24 m2) of the pond surface area. Ponds were not fertilized during the grow-out period. After the first fertilization before prawn stocking, the ponds were left 10 days to allow plankton development in water column and periphyton growth on bamboo kanchi. Collection of prawn juveniles: The juvenilies of Macrobrachium rosenbergii (5 ± 0.04g) were purchased from a nearby commercial hatchery.The fingerlings of tilapia Oreochromis niloticus (24.3 ± 0.24g) were collected from Bangladesh Fisheries Research Institute (BFRI). Stocking: Juveniles of Macrobrachium rosenbergii (5 ± 0.049) procured from a nearby commercial hatchery were stocked at 3 juveniles m^-2 in the ponds and nursed juveniles of Oreochromis niloticus (24.3 ± 0.24g) were stocked according to the experimental design. Feeding: Juvenile of freshwater prawn fed with processed palleted feed containing 30.03% crude protein daily at a rate of 10% of the body weight for 1st month 7% of the body weight for 2nd month and 3% of the body weight for rest of the cultured period. Half of the required feed for a day was supplied in the evening and rest half in the morning. Feed requirement were calculated and adjusted after sampling of prawn in a month. Locally purchased tapioca starch was used as carbohydrate source for manipulating the C/N ratio. In order to raise the C/N ratio to 20 in all the ponds, 0.9kg tapioca starch was applied for each kg of formulated feed. The pre-weighed tapioca starch was mixed in a beaker with pond water and uniformly distributed over the pond’s surface directly after the feed application at 7.00 am. Collection of benthos: The benthic macroinvertebrate samples were collected monthly with an Ekman dredge (covering an area of lower month 225 cm2). In each pond, bottom mud samples were collected from 3 different locations and washed through a 250µm mesh size sieve. Benthic macroinvertebrate remaining on the sieve was preserved in a plastic vial containing a 10% buffered formalin solution. Benthic macroinvertebrate density was calculated using the formula: N =Yx10000/3A Where, N=the number of benthic organisms (number m-2); Y=total number of benthic organisms counted in 3 samples; A = area of Ekman dredge (cm2). Analysis of experimental growth data: Experimental data collected during the growth trial were used to determine the growth parameters.

Source of Information: J. Agrofor. Environ. 5 (1): 63-66, 2011; ISSN 1995-6983

Article Link (Online Journal):

Funding Source:

Total Budget (Tk.) :

Achievement/Findings:

The mean initial weights (g) were 5.0 and 4.9 in treatments PT0.5 and PT0. There was no significant difference (P>0.05) in initial weights of prawn juveniles at stocking between different treatments. Final weight and weight gain was significantly higher (P<0.05) in treatment PT0 than those in treatment PT0.5. Specific growth rate was significantly higher in PT0 than in PT0.5. The addition of tilapia decreased the gross and net yield of prawn. Tilapia had significant effects on FCR of fresh water prawn, substrates decreased FCR by 13.5% whereas addition of tilapia increased 16% gross yield.

Knowledge Management: Journal