Supply of fish fingerlings is scarce and usually expensive in northern Bangladesh. It is also tedious for fish farmers to procure fish seeds. An alternative is the production of common carp (Cyprinus carpio) fingerlings in different types of boro or irrigated paddy. Although production figures are below the commercial rates, small farmers can grow their own fingerlings at minimal cost.
The four types of irrigated paddies for fingerling production (as practiced by farmers in northern Bangladesh) have the following features:
Soil |
clay loam |
Water supply |
irrigated |
Water depth |
maintained at 7.5-10 cm |
Area range |
12.5-1 320 mē |
Fish species |
common carp |
Rice variety |
Bangladesh rice (BR)-3, |
Calendar of activities in fish production
1. Fish hatchlings of fry can be reared in different types of boro paddy plot designs without altering the farmer's normal practices in rice production.
2. Farmers' existing resources can be used.
3. Only minimum additional expenses are required.
4. When the fish get bigger than 2.5 cm, they control weeds, pests and insects in the paddy
5. Fish faeces serve as fertilizer for rice.
6. Additional income can be pro-vided.
7. Farmers can sell fingerlings when prices are highest.
1. Paddy soil should have good water-holding capacity.
2. Common carp is recommended for stocking for these reasons:
- it spawns earlier;
- fry are available at the same time
- as boro rice transplantation; and
- it is a hardy fish.
Tilapia can also be stocked.
3. Fish have higher survival rates in smaller paddies.
4. If possible, use fry (instead of hatchlings) for stocking because they have higher survival rates.
5. Use of supplementary feed, like rice bran or wheat bran, can help increase fingerling production at very minimum cost.
6. To reduce risks of paddy field drying out, use treadle pumps to pump water.
Production details between stock of fry and hatchlings (based on a 1 320 mē paddy)
Partial (in Taka) budget for common carp fingerling production in boro paddy (based on a 1 320 mē paddy)*
* Records from ODA/CARE/BRAC Rice/Fish Pilot Project, Rangpur (1991)
Comparative budget and income (in Taka) from three systems: rice, rice and common carp hatchlings, and rice and common carp fry*
Rice |
Rice and hatchlings |
Rice and fry |
|
Rice production |
|||
Cost |
|||
Inputs |
684 |
601 |
601 |
Labour |
492 |
509 |
509 |
Irrigation charges (Tk500/bigha) |
500 |
500 |
500 |
Interest on operating costs (16% per annum or 1.33%/day) |
89 |
85 |
85 |
Income |
3 855 |
3 943 |
3 943 |
Return for rice |
2 090 |
2 248 |
2 248 |
Fingerling production |
|||
Cost |
|||
Fingerlings (Tk0.50/pc) |
NA |
462 |
1 056 |
Family labour |
|||
Interest on operating costs (16% per annum or 1.33%/day) |
12 |
20 |
|
Income |
NA |
1 337 |
2 640 |
Return for fish |
NA |
863 |
1 564 |
Return for plot |
2 090 |
3 111 |
3 812 |
Total |
9 800 |
13 671 |
16 978 |
* Records from CARE/ODA/BRAC Rice/Fish Pilot Project, Rangpur (1991) |
|||
Issues for further consideration This approach has expanded dramatically in northwest Bangladesh since the case study was written. CARE-Bangladesh have promoted both spawning and nursing of common carp using a farmer field school approach with good success. They promote stocking of fertilized eggs produced by the farmers themselves in the ricefield. Farmers in Rangpur district have sustained their use of the technique to meet their own fingerling needs, although there seems to have been little expansion into any commercialization. In 1999, the production of tilapia seed in dry season boro ricefields was tested using a similar approach to that tested in Thai Binh province, northern Vietnam. There are numerous advantages to this approach for tilapia production, not least of which is a match between timing of fish seed supply with demand early in the monsoon season. In Bangladesh, this method has been beneficial in important fish culture areas in which tilapia production has been constrained by lack of seed. The described method of breeding common carp has been traditionally practiced in northern Laos and Viet Nam. |
