Fish

Classification

•Kingdom- Animalia•Phylum- Chordata•Sub Phylum- Vertebrata•Classes- Agnatha, Chondrichthyes, Osteichthyes

Fish Characteristics•Gills•Backbone (vertebrae)•Paired Fins•Single Loop Circulation•Two chambered heart

Fish Anatomy

Fins

Different Dorsal Fins

Fish Respiration• Water flows over Gills as fish

opens mouth and swims.• Water flows opposite

direction of blood flow.

• O2 diffuses from the water into the blood.

• Gills are made of thousands of gill filaments.

• Gills are covered by the Operculum.

Up Close and Personal

Fish Circulation• Fish heart has 2 chambers• Single loop circulation

• Blood flows into gills, picks up O2, goes to the body, returns to the heart.

Fish Reproduction• Most Fish reproduce sexually, and

fertilize their eggs externally (Sharks-internally).

• Spawning is the process of fertilizing eggs.

• Baby fish are called FRY.

Fish Adaptations• Lateral Line System- used to detect

vibrations, orient the fish in water, it is a line of cells running down the side of the fish.

• Operculum- gill cover, movement of operculum allows more water to be drawn in.

• Swim Bladder- a gas filled sac that helps the fish maintain buoyancy. Sharks don’t have a swim bladder!

• Fins- Dorsal, Caudal, Pectoral, Pelvic, Anal.

Adaptations

Air Bladder Operculum Lateral Gills Line

Fins

AgnathaJawless fish: Lampreys,

Hagfish

Types of Agnathans•Hagfish- Ocean

scavengers, not much is known about them.

•Lamprey- fresh and salt water, they are parasitic and prey on other fish.

* Both have cartilagenous skeletons and sucker-like mouths.

ChondricthyesCartilagenous Fish: Shark,

Ray

Chondrichthyes• Sharks are adapted for a predatory

lifestyle.• Cartilage skeletons, stiff pectoral fins

(speed).• No operculum, must keep moving to

breathe.• Have live births.• Special scales feel like sandpaper.• Manta, and Sting Rays- live in

shallow water, have mouths located on the underside, are fairly docile, wide flat bodies and wing-like fins that are flexible.

Types of Chondrichthyes• Sharks and Rays-

have no operculum and must keep moving to breathe.

• Have different kinds of scales that feel and look more like sandpaper.

• Have skeletons made of cartilage not bones.

Osteichthyes

Bony Fish: Salmon, Carp, Tuna

Over 20,000 different species

Types of OsteichthyesRay Finned:

– Most fish are this type– Fins are supported by bony

structures called Rays.– Teleosts are the most advanced

form of ray finned fish (symmetrical tails and mobile fins).

Lobe Finned:– Fins are long, fleshy, muscular,

supported by central core of bones.

– Thought to be ancestors of amphibians.

– Examples are: Coelacanth, Lungfish