Phoning for fingerlings?
You
wait your turn to use the phone. You dial. You wait. Silence. The connection
breaks. You try again. In some countries it can be a very frustrating
business trying to place an order by telephone. For fish farmers in a
country such as Cameroon, where telephones as well as fish farmers are
few and far between, trying to place an order for fingerlings is no easy
task. Even supposing you have relatively easy access to a telephone, it
is probable that you will have some distance to travel by road to collect
the order. Unexpected delays on the road are not uncommon. They can be
infuriating for the driver... and fatal to the fish. If pond owners could
raise their own fingerlings, fish farming would be a far more attractive
enterprise.
Catfish sell for twice the price of tilapia, and their taste is preferred, but they have a serious drawback for fish farmers. Like most fish they need environmental stimuli, such as rising water levels, before they will breed and lay eggs. In artificial ponds with clean, well-regulated water levels, the female African catfish (Clarias gariepinus) is very reluctant to lay her eggs. Catfish eggs, larvae and fingerlings can be raised in hatcheries, and these also have the advantage of keeping the young safe from predators, but hatcheries require an expensive infrastructure and are beyond the means of all but big commercial or government enterprises. However, pond owners wishing to raise catfish in the Western Province of Cameroon may soon be able to take advantage of development work at the Institute of Agricultural Research and Development's hatcheries in Foumban.
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Concerned about the difficulties that pond owners face in obtaining fingerlings, Steve Sulem, research scientist at the Institute, has been testing the Asian system of 'hapas' under Cameroon's conditions. Hapas are small mesh net cages, usually about a metre square and can be made out of the kind of bags in which rice is sold. They are placed in ponds, with the rim above water level, so that the larvae or eggs put inside them cannot flow out. The bottom may reach the floor of the pond and inside a layer of bottom mud can be placed in order to encourage the development of small organisms which the fish can eat. The top can be covered to protect against predators.
Pond owners can buy hormones from a pharmacy more easily and with less risk than buying fingerlings. The hormones are injected into the female fish which then lays eggs. A male fish (easily identifiable) is killed, its testes are removed and pressed over the eggs to fertilize them. They are then mixed with water and sprayed into the hapas. In a few days, depending upon temperature, the fish larvae will hatch and grow on in the hapas, secure from predators, until they are large enough to be let out into the main pond. Steve Sulem is convinced that pond owners will find this system simple to learn and practise... and far easier than struggling with the telephone system.
