Coastal Aquaculture and Mariculture

Unit 5 - Major groups of Fisheries in India

5.2.2. Bombay-duck
The Bombay-Duck, Harpadon nehereus belongs to the family, Harpadontidae. It is supported by this single species only. It forms a commercial fishery in the northwest along Gujarat and Maharastra coast; also available in northeast coasts of India. It exerts a pronounced influence on the livelihood of men and women engaged in this labour intensive sector in Maharashtra and Gujarat.
Distribution
Global
It is distributed along Tanzania to China coast; India, Pakistan, East Pakistan, Burma and straits of Malacca coasts.
India
It is discontinuously distributed along the Indian coasts.
Discontinuous distribution
Bombay duck occurs in large quantities on the west coast of India from Ratnagiri in the south to Jaffrabad in the north in the Gulf of Cambay. On the east coast, it is taken in small numbers north of Chennai and along the Andhra coast. But there is a good Bombay-duck fishery exists in the estuaries of the rivers in Orissa and West Bengal.
Production trend
It is abundant along the northwest coast of India contributing around 90% of all India landings of this resource followed by West Bengal and other states. This species contributes about 5% of all India marine fish landings. The Bombay duck catch ranged from 51, 570 (1972) to 1, 26, 044 t (1979) during 1958 -1979 constituting 5.02% to 14.01%. The present average annual landing has been estimated at 1.1 lakh tonnes by traditional and industrial sector along the northwest (88%) and northeast (12%) coasts of India.
Recent production

(Source: CMFRI, Annual Reports)

Size composition
Larger and older fishes are usually scarce in commercial catches. Fishes ranging from 30-330 mm, in total length support the fishery. Indetenninate and immature fish below total length of 208 mm constitute seventy percent of the landings.
Mode of exploitation
Stationary bag net / fixed bag net is the principal gear used for the capture of Bombay- Duck. This gear is known as dol in Gujarat and Maharashtra and as beenjal/ behundijal or thorjal in West Bengal. Boat seines are used on the Andhra -Orissa Coasts.
Food and feeding
They are piscivorous and to some extent cannibalistic. They feed on the juveniles of their own species, other fishes and non-penaeid prawns. The crustaceans like Acetes indicus and Palaemon tenuipes and fishes like Coilia dussumieri. Polynemus species and Heptadore typus form the main constituents of diet.
Minimum size at maturity
Minimum size at maturity in the female is between 200 -240 mm. They normally attain maturity at the end of second year.
Spawning
It is a continuous spawner but the individuals are out of phase with each other. However, two peak spawning periods, May-July and November-December commonly occur.
Fecundity
It ranges from 15,000 to 1, 50,000 based on the size and age.
Utilization
The catches are sold fresh. As the yield is low in these days, commercial drying on bamboo scaffoldings which was very common in the past, does not take place now. It is also a valuable export item in dried or laminated form. Fresh extracts have considerable medicinal properties. It is a highly perishable fish due to high water content. Hence, it has to be disposed off quickly if it is to be consumed fresh.
Conservation and management
The area of production (offshore) and area of harvest (coastal water) differs. This renders projection of total availability complicated not only by the mobility of the species but also by the reaction of the species to coastal environmental factors and intensity of fishing effort. Therefore, the fluctuations in yield are likely to be a reflection of changes in the 'catchability'. The Bombay- duck has been exploited with a mixture of success and failure in the past. Large- scale landings of indetenninate and immature fish have been a source of concern since long. Hence, it is necessary to regulate the mesh size.