Subject : Agricultural Science
Class : Jss 2 / Basic 8
Term : Third Term / 3rd Term
Topic : Definition of Fishery
Behavioural Objectives : By the end of the lesson , learner will be able to
- Say the definition of Fishery
- Give various examples of Fish
- Mention the classification of Fish
- write out other Types of Aquatic Organisms
- Teacher arrange a visit
to a nearby fish farm
Presents pictures and
chart on fish and fish products
- Definition of Fishery
- Examples of Fish
- Classification of Fish
- Other Types of Aquatic Organisms
Definition of Fishery
Fishery refers to the management and production of fish and other aquatic animals. Of all animals living in water, fish is the most plentiful of them. Fish belongs to the group of aquatic vertebrates i.e. they have back bones. They are specially adapted to live, raised and reproduced in water.
The shape of their body enables them to move easily in water; swim bladder helps them to maintain their balance while the gills are used for respiration. All aquatic animals are found in water bodies such as lakes, pond, streams, rivers, oceans, lagoons and swamps. Other aquatic animals include whales, dolphins, shrimps, lobster, hippopotamus etc.
Parts of a Fish (Diagram)
Examples of Fish
Some examples of fish are:
- Cat fish
- Mud fish
- Nile perch
- carps tilapia
- Croaker etc.
Classification of Fish
Fish can be classified into two based on (i) habitat and (ii) morphology (structure).
Classification of Fish based on Habitat
- Fresh water fish
These are fish that can successfully live and reproduce only in salt free water such as ponds, lakes, streams, rivers, swamps etc. Examples of fresh water fish are tilapia, cat fish, Nile perch, mud fish, dogfish, moon fish, etc.
- Salt water fish
These are fish which can live and reproduce successfully in saline (salt) water like lagoons, oceans, and seas. Examples are dog fish, shark, croaker, sole, and mackerel e.t.c.
Classification based on Morphology
- Bony fish
These are fish that have the structure of their body made up of bones e.g. tilapia, carps, cat fish, croaker, mackerel, etc.
- Cartilaginous fish
These are fish which have the structure of their body made up of cartilage e.g. dog fish, rays, shark, etc.
Other Types of Aquatic Organisms
There are many other organisms that are living inside water, apart from fish which are used as food by man. These include;
- Crustaceans (shell fish): Such as prawns, shrimps, crayfish, lobsters and crabs.
- Reptiles: Such as river snake, turtles, and crocodiles.
- Mammals: Such whales, Hippopotamus, dolphins, seals and porpoises.
- Molluscs (Snails): Such as river snails, periwinkle, oyster, squid, clam and octopus.
- Define fishery.
- Enumerate two classifications of fish based on habitat.
- Enumerate two classifications of fish based on morphology.
- What are aquatic organisms?
- Give two examples each of the following: (i) Reptiles (ii) Molluscs (iii) Crustaceans
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