Biology Ch25 - (Verebrate Diversity)

Endoskeleton

Internal skeleton built of bone or cartilage

Braincase

Skull to protect the brain

Vertebrae

Backbone to protect the spinal cord

Bones or cartilage

To support and protect the body soft skills

Dominant aquatic vertebrates

Fish

Gills

Specialized organ to allow fish to breathe underwater; large sheet of thin tissue filled with capillaries

Take in dissolved oxygen from water, release carbon dioxide

Lateral line

Sensory system, sensitive to small changes in water movement helps to keep them balanced

Swim bladder

Helps a fish float higher or lower in the water

Three classes of fish

Jawless fish, cartilaginous fish, bony fish

Jawless fish

Ex: hagfish; mostly parasites

Cartilaginous fish

Ex: sharks; have skeletons made from cartilage and calcium carbonate, they have tough skin with placoid scales

Bony fish

Bony endoskeleton, cycloid scales or disk, operculum covering the gills, and swim bladder

Operculum

Protects a bony fish’s gills; movements of it help bony fish move water over gills

Bony fish include

Ray finned and lobe finned fish

Ray finned fish

Have fins supported by a fan shaped array of bones; embedded in a thin layer of skin and connective tissue, it’s lightweight, can fold up, and easy to move

Ray finned fish

Long torpedo shaped bodies (barracuda), they are predators that can swim fast and surprise their prey

Ray finned fish features

Can breathe air and survive out of water for several hours at a time

Lobe finned fish features

Rounded fins supported by a single bone; pectoral and pelvic fins that are round in shape, not as maneuverable as ray fins, able to support weight

Amphibians

Animals that can live both on land and in water

Amphibians characteristics

Four legs, moist skin with no scales, gas exchange the skin or lungs, three chambered heart, reproduce externally and their eggs are covered with sticky substance

Ectotherms

Animal that is dependent on external temperature to regulate body heat.

Amphibian adaptations

Large shoulder and hip bones, mobile and muscular tongue, middle ear, breathe through skin or with gills or lungs

Amphibians’ strategies to keep eggs wet

Lay eggs directly in water, lay eggs on moist ground, wrap eggs in leaves, brood eggs in pockets on the female’s back

Frogs metamorphosis

Fertilizer egg hatches into a tadpole, which grows legs

Tadpoles tail and gills disappear and it becomes a young adult

Three groups of amphibians

Salamanders, frogs, caecilians

Salamander features

Long body, four walking limbs, and a tail

Frogs’ features (includes toads)

Glands in skin contain poisons that help protect them from predators

Caecilians’ features

Legless, burrowing, tropical amphibians

They have internal fertilization