INTRODUCTION TO F ISHESPART 1

Fisheries

Introduction to Fishes

What is a fish?

A limbless cold-blooded vertebrate animal with gills and fins and living wholly in water.

Introduction to Fishes

Fish are vertebrates.

Cold-blooded. Their temperature varies with that of their

surroundings.

Most reproduce by laying eggs. Fertilized externally.

Body Types

Six main body types

Body Types

Flat (rays, skates, flounder, sole)

Body Types

Fusiform (sharks, salmon, barracuda, tuna)

Body Types

Elongated (ells, lamprey, needlefish)

Body Types

Compressed (butterfly fish, angelfish)

Body Types

Round (porcupine fish)

Body Types

Ribbon (cutlass)

Scales

Point away from the head (towards tail fin).

Ctenoid – jagged edges.Cycloid – smooth, round edges.

Lateral Line

This organ lays is a series of fluid-filled ducts located just beneath the scales.

Picks up vibrations in the water for: Detecting predators Finding food Navigation

Fins

Used for movement, stability, steering, nest building, and spawning.

Fins

Caudal Fin: For propulsion. Fast swimmers have a forked caudal fin.

Dorsal Fin: For stability.

Anal Fin: For stability.

Pectoral Fins: For manoeuvring (steer and brake).