Aquaculture is the act of rearing selected species of fish, shrimbs , crabs, etc under scientifically-controlled conditions in enclosed bodies of water such as ponds, streams and rivers where they feed, grow, breed and are harvested for consumption or for sale.
TYPES OF AQUACULTURE
The different types of aquaculture are:
- Fish farming.
- Shrimp farming.
- Crab farming.
DEFINITION OF FISH FARMING
Fish farming (culture) is the act of rearing selected species of fish under scientifically controlled conditions in enclosed bodies of water such as ponds, streams, rivers, etc ., where they feed, grow, breed and are harvested for consumption or for sale.
Terms Associated with Fish Farming
- Fingerlings: The newly hatched fishes.
- Fisheries: This is the study of fish and fishes.
- Fish: This refers to a particular species, regardless of the number or quantity.
- Fishes: This refers to the different species of fish.
- Pond: This is artificial body of water where fish(es) can be reared.
- Gears: These are equipment used in harvesting fish.
- Fry: This refers to young fish(es) or baby fishes.
- School: This is a group of fish(es).
- Hatchery: This refers to a unit where fish eggs are incubated and hatched artificially into fish.
- Aquarium: This is an artificial fish pond kept for aesthetic or entertainment purposes at home.
- Aquaculture: This refers to the study and production of fish, shrimps and other aquatic food organisms.
Importance of Fish Farming
Fish farming is important for the following reasons:
- It provides fish which serves as a source of food, e.g ., protein to man and livestock.
- It provides a means of increasing the availability of protein to people at reduced cost.
- It provides a means of recycling wastes, e.g ., animal dungs from farms, factories and sewage disposal systems.
- Fish can be processed into fish byproducts such as fish meal, fish oil, manure and skin.
- It provides employment and income to many people.
- A better use of land and water in our environment is also ensured through fish farming.
- It can generate foreign exchange to a nation, especially when fish are exported to other countries.
- Fish farming is also useful in the area of research work and other educational purposes.
CONDITIONS OR FACTORS NECESSARY FOR SITING A FISH POND
The factors or conditions necessary for siting a fish pond include:
- Adequate water supply.
- Soil in the area.
- Vegetation of the area.
- Topography of the area.
- Availability of fast growing fishes.
- Availability of supplementary feedstuff.
- Adequate water supply: There must be constant supply of water of good quality and quantity. The water can be from streams, lakes, rivers, irrigation canals and springs. Good quality water is necessary because it will provide oxygen and food to fish, create a medium for waste discharge and reproduction. The water should not have a bad smell, taste or colour and should not be too muddy and must be free from pollution.
- Soil in the area: Soil in the area must be fertile so as to supply nutrients to the fish. It should be clay because of its ability to hold water which is very important in fish pond construction. Soil with too much sand or gravel is not good and would not retain water.
- Vegetation of the area: Low vegetation, especially grasslands are preferred. Woody sites are not suitable because clearing and stumping will greatly increase the cost of setting up the fish pond.
- Topography: The shape of the land should allow for easy draining and filling of pond with water. The water must flow from a place that is higher than the pond so that the water can flow into the pond directly. If not, the need for water pumps would arise and this will increase the cost of the project. However, fishpond can be constructed on a flat or level ground but lots of soil have to be removed to create the slope.
- Availability of fast growing fish: Fingerlings or baby fishfor stocking a fish pond should be the type that can grow fast and mature within a very short time. The use of improved varieties (breeds) in stocking fish pond makes fish farming more profitable .
- Availability of supplementary feedstuff: Supplementary feeding is done to ensure rapid growth of fish and allow high stocking density. Artificial or compounded feeds in form of pellets are used to supplement the natural feed (planktons) The addition of fertilizers also promotes the rapid growth of planktons (natural fish food) in the pond.
CLASSIFICATION OF FISHES
Fishes can be classified into two main groups:
a) Classification based on fish habitat
Under this classification, two groups exist:
- Fresh water fishes: These fishes live in fresh water, i.e ., the water does not contain salts. Examples of such fresh water are pond, streams, rivers and lakes. Examples of fishes in this group are tilapia, carp, perch, trout and mudfish.
- Salt water fish: These fishes live in water containing salts such as lagoons, seas and oceans. Examples of salt water fishes are salmons, mackerel, shark, tilapia, rays and eels.
b) Classification based on body structure
Under this classification, two groups also exist.
- Bony fishes: These fishes possess bony skeletons. Examples are tilapia, mudfish, carps, trout. catfish, salmon, perch and herring Majority of these fishes are found in fresh water.
- Cartilaginous fishes: These fishes possess soft bones composed of cartilages. Majority of these fishes are found insalt water and examples are shark, dolphin, dogfish and rays.
Scientific names of fish species commonly stocked in a pond
- Clarias spp.
- Chrysichtys nigro digitatus.
- Gymnacus niloticus.
- Tilapia spp.
- Lates nilotica.
- Gypramus carpis.
- Heterotis niloticus.
- Labeo spp.
- Heterobranclues spp.
- Hypothmichitys spp.
- Ophiocephalus spp.