Polyculture of Mola with Carps

Mola is a micronutrient-rich small fish that is very popular, and grows well along with carps in ponds and rice fields. The concept of polyculture of mola with carp is not new in India. However scientific practice of polyculture of mola has not not been initiated seriously in our region. Carps are one of the most commonly farmed fish by small-scale farmers in Bangladesh. Carps grow to a large size and are profitable when sold at the market. Two sustainable, low-cost technologies practiced In Bangladesh are:

Culture of carps and mola in stand-alone ponds and culture of carps and mola in ponds connected to rice fields, have been developed to increase production and productivity. These technologies has boosted household income for millions of Bangladeshis, and help build healthy families through the consumption of micronutrient rich mola. Culturing mola and carps in ponds connected per year to rice fields yielded up to 7.4 metric tons fish per hectare, and up to 3.6 metric tons fish per hectare per year in stand-alone ponds.

Stocking of mola:

• Fish should only be added to the pond if there is abundant natural food present.
• Mola brood should be stocked during the first week of April. Mola spawns shortly after stocking and schools of fry are visible after 20 to 25 days. Netting should not be done at this time.
• Mola brood need to be stocked only once in a perennial pond, as they continue to spawn, laying their eggs in the floating and submerged vegetation near the banks of the pond.

Feed and feeding of mola:

Mola is a planktivorous fish which feed mainly on chlorophyceae, Bacillariophyceae and debris with mud. So abundant of phytoplankton in mola pond will yield good results.

Benefits of carps and mola polyculture in ponds connected to rice fields:

• Increased rice (10%) and straw (15%) yield
• Two crops produced from the same land at the same time, with relatively low costs and labour
• No need for application of insecticides as the fish feed on insects and pests in the rice fields
• Fish movement in the rice fields reduces the growth of weeds
• As rice field dry out during the winter months, they provide a healthy habitat for fish when they become flooded during the monsoon
• Most ponds connected to rice fields are close to homesteads, which is convenient for women who take care of them and for harvesting fish for home consumption.

Partial harvest of mola for household consumption:

Mola spawn 2 to 3 times a year, so the fish should be partially harvested frequently. Without partial, frequent harvesting, the density of mola will increase, resulting in food scarcity in the pond.

Benefits of producing mola:

• Can be grown alongside carps in ponds and ponds connected to rice fields
• Can increase the production, productivity and nutritional quality of fish produced in ponds and ponds connected to rice fields. It can consider as a supplier of Vitamin A.
• Only need to be stocked in the pond once as they will continue to breed if a small amount of water is retained in the pond throughout the winter season
• Command a high market price
• Are popular in the entire north-eastern people diet
• Should be partially harvested regularly–these harvests can be used for household consumption
• Are rich in micronutrients, particularly vitamin A, calcium, iron and zinc

Mola for Income: A preliminary survey shows that the average annual income of a small and marginal farmer was estimated at US$347 from carp mola production. It is estimated that an average 14% income has increased because of presence of mola in the ponds or in the rice fields in Bangladesh.

Mola for Income: A preliminary survey shows that the average annual income of a small and marginal farmer was estimated at US$347 from carp mola production. It is estimated that an average 14% income has increased because of presence of mola in the ponds or in the rice fields in Bangladesh.