Fish Farming & Classification Of Fish JSS2 Agricultural Science Lesson Note

 FISH 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 sale.

Terms Associated with Fish Farming

Fingerlings- The newly hatched fish (es).

Fisheries-    This is the study of fish and fish.

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 water where fish (es) can be reared.

Gears  –       These are equipment used in harvesting fish.

Fry  –       This refers to young fish (es).

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:

(i)       It provides fish which serves as a source of food, e.g., protein to man and livestock.

(ii)  It provides a means of increasing the availability of protein to people at reduced cost.

(iii) It provides a means of recycling wastes, e.g., animal dung from farms, factories, and sewage disposal systems.

(iv) Fish can be processed into fish by-products such as fish meal, fish oil, manure, and skin.

(v)      It provides employment and income to many people.

(vi) A better use of land and water in our environment is also ensured through fish farming.

(vii) It can generate foreign exchange for a nation, especially when fish are exported to other countries.

(viii)   Fish farming is also useful in the area of research work and other educational purposes.

   CLASSIFICATION OF FISH

Fishes can be classified into two main groups:

(a)     Classification based on fish habitat:  under this classification, two groups exist:

(i) Freshwater fishes:  These fishes live in freshwater, i.e., the water does not contain salts. Examples of such freshwater include ponds, streams, rivers, and lakes. Examples of fish in this group include tilapia, carp, perch, trout, mudfish, etc.

(ii) Saltwater fish:  These fishes live in water containing salts such as lagoons, seas, and oceans. Examples of saltwater fishes include salmons, mackerel, sharks, tilapia, rays, eels, etc.

(b)  Classification based on body structure:  under this classification, two groups also exist:

(i)  Bony fishes:  These fishes possess bony skeletons. Examples include tilapia, mudfish, carp, trout, catfish, salmon, perch, and herring. The majority of these fishes are found in freshwater.

(ii)  Cartilaginous fishes:  These fishes possess soft bones composed of cartilage. The majority of these fishes are found in saltwater and examples include sharks, dolphins, dogfish, and rays.

Classification based on the nature of body covering:

(i) Scaly fish: these are fishes that have scales on their body e.g tilapia, croaker e.t.c

(ii) Non-scaly fish: these are fishes that have no scales on their body. E.g mackerels, catfish, mudfish e.t.c