WEEK 1/2: FISHERY - Classes of Fish

                  AGRICULTURAL SCIENCE

WEEK2:   FISHERY, CLASSES OF FISH

Meaning of Fishery – refers to the area of agriculture concerns with the capture and cultivation of fish and other aquatic organisms include processing and selling of them.

Fishing – Is the act of catching fish and other aquatic organisms.

Fishes: are cold blooded animals. That is the temperature of the body of a fish changes with the temperature of the surrounding environment. Fishes belong to the vertebrate group known as pisces and they breathe with the aid of gill.

CLASSIFICATION OF FISH

Fishes could be classified into two main ways

a.     Classification of fish based on its body structure /morphology.

b.     Classification based on their habitat.

A.  CLASSIFICATION BASED ON MORPHOLOGY:

1.     Bony fish – are fishes that possess a bony skeleton or hard bone (made of bone). They are therefore, called bony fish. These include tilapia, cat fish and coraker etc.

2.     Cartilaginous fish: These fishes that possess soft body. Their body frame (skeleton) is made up of a firm and elastic substance called cartilage e.g sharks, salmon, and dolphins etc.

B.     CLASSIFICATION OF FISHES ACCORDING TO THEIR HABITAT

i.      Fresh water fishes – are capable of living and reproducing only in fresh water like inland rivers, streams or ponds examples include front and mud etc.

ii.     Salt/marine water: These are found in seas and oceans. Marine fishes can be grouped into two: Those which live at or near the surface of the water are called pelagic” marine fish while those that live at or near the bottom of the sea are called demersal.

EVALUATION QUESTION:   1. What is fishery?        2. Name the two classifiction of fish.         3. Explain Cartilaginous fish.             4. The marine fish that live at or near the bottom of the sea are called what?