What is a vertebrate Animals with a backbone

What is a vertebrate? ---Animals with a backbone or vertebral column (endoskeleton) ----Have spinal cord - dorsal, hollow nerve cord ----Front end of spinal cord develops a brain (cephalization) ---- Closed circulatory system

Vertebrate Classes • Jawless Fish (lamprey, hagfish) • Cartilage Fish (sharks, rays…) • Bony Fish (salmon, catfish, goldfish…) • Amphibians (frogs, salamanders…) • Reptiles (lizards, turtles…) • Birds (sparrows, hawks…) • Mammals (humans, whales, cats. . )

FISH

Fish Classification • Kingdom- Animalia • Phylum- Chordata • Sub Phylum- Vertebrata • Classes- Myxini, Cephalaspidomorphi Chondrichthyes, Osteichthyes

Fish have a two chambered heart – and single loop circulation: blood is passed over the gills where it picks up oxygen, goes to the body and returns to the heart

Fish Respiration • Water flows over Gills as fish opens mouth and swims. • Water flows opposite direction of blood flow.

Fish Respiration • O 2 diffuses from the water into the blood. • Gills are made of thousands of gill filaments.

Reproduction • Most fish lay eggs that are fertilized externally - called spawning • Some fish bear live young

The Nervous System - Cerebrum - thinking, voluntary activities - Cerebellum - coordination - Medulla Oblongata - functions of internal organs (involuntary) - Lateral Line System - senses vibrations

Class Myxini and Cephalaspidomorphi Jawless fish: Hagfish and Lampreys

Types of Jawless Fish • Hagfish (class Myxini)Ocean scavengers, not much is known about them. Hagfish Slime Video • Lamprey (class Cephalaspidomorphi) fresh and salt water, they are parasitic and prey on other fish. * Both have cartilagenous skeletons and sucker-like mouths. Lamprey Video

Class Chondrichthyes Sharks and Rays • Cartilage skeletons, no bones • No operculum, must keep moving to breathe. • Have live births. • Special scales feel like sandpaper.

Types of Chondrichthyes • Sharks Lemon Shark Birth Video • Sharks are adapted for a predatory lifestyle. • Cartilage skeletons, no bones stiff pectoral fins (speed).

Types of Chondrichthyes • Rays Manta, and Sting Rayslive in shallow water, have mouths located on the underside, are fairly docile, wide flat bodies and wing-like fins that are flexible. Rays and Skates comparison

Class Osteichthyes Bony Fish: Salmon, Carp, Tuna

General Fish Characteristics • Gills • Backbone (vertebrae) • Paired Fins • Single Loop Circulation

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.

Types of Osteichthyes Ray Finned – Most fish are this type – Fins are supported by bony structures called Rays.

Types of Osteichthyes Lobe Finned – Fins are long, fleshy, muscular, supported by central core of bones. – Thought to be ancestors of amphibians. – Examples are: Coelacanth, Lungfish