fishies classes: agnatha, chondrichthyes, and osteichthyes

FISHIES

Classes:

Agnatha, Chondrichthyes, and Osteichthyes

______ are the dominant aquatic vertebrates.

Fish have adaptations to an aquatic environment that make their movements through water

________________________

_______________South American Freshwater Fish

Internal Anatomy of _____ Fish

________________

• Large sheets of thin frilly tissue filled with capillaries that take in dissolved oxygen from the water and release carbon dioxide.

Circulatory system:pumps blood in a single loop through a

__________ chambered heart.

Countercurrent Flow

• The _____________ movement of water against the flow of blood in the fish’s gills.

• Maximizes the amount of oxygen the fish can pull from the water.

Swimming and Maneuvering

• Most fish swim by contracting large segmented muscles on either side of their body from the head to the ___________.

• This makes an S-shaped wave that pushes it through the water.

• They counteract these movements with their _____________.

_______ Anatomy of Bony Fish

Fins

• Surfaces that project from a fish’s body

• Keep the fish _________________

• Direct the movement of the fish

Fins

_______________________Class Agnatha

• Existed since the Cambrian and continues to live • Do not have paired fins• Have a notochord in both larvae and adults• Light sensitive pineal eye• No identifiable __________________• Ectothermic• Two-chambered heart• External Fertilization

Sea LampreyPetromyzon marinus

HagfishMyxine glutinosa

Jaws

• Evolved from gill arches

• Most jawed vertebrates have teeth on their upper and lower jaws.

• Teeth used to ________________ and process food

Jaws

• Gave vertebrates a huge advantage as predators and pushed them to the top of the _________________.

Two groups of jawed fish still exist:

Cartilaginous Fish

and

Bony fish

Cartilaginous Fish

• Skeletons made of cartilage while ancestors had skeletons made of bone

• They have lost the ability to make ___________________

• Cartilage is unique – it’s stronger than human cartilage.

Two Groups of Cartilaginous Fish

• Holocephali: chimeras • Elasmobrachs: sharks, rays and skates

Holocephali: chimeras

• Small group of deep-sea fish with platelike grinding teeth.

• Feed on crustaceans and other invertebrates

Elasmobranchs: sharks, rays and skates

• ___________ species of sharks

• 400 species of rays and skates

Ray Skate

Sharks

• Most hunt other ________________

• Some eat seals and sea lions

Biggest Sharks

_____________

Feed on plankton, krill

and algae

Basking Sharks

Filter feeder, eats plankton

Great White Shark

All Fish

• Have a ______________________system– This is a series of shallow canals on the sides

of the fish made up of cells that are sensitive to small changes in water movement.

– This allows them to have a sense of “distant touch”.

External Anatomy of Bony Fish

Class OsteichthyesBony Fish

• More than ______________ species

• Living in nearly every aquatic environment on Earth

• Some have become parasites of other fish

• One group can even spend short periods of time on land

Characteristics

• internal skeleton ossified (i.e., endochondral bone)

• ____________________or lung present

• bony scales (ganoid, cycloid, ctenoid, or cosmoid)

• gill slits covered by an operculum (single external gill opening)

• late Silurian to Recent

____________________

• Genus Hippocampus • Unique because

males become pregnant when the females deposit the eggs into the birthing pouch.

Nile Knifefish

• Will aggressively bite anything that moves

• Discharges an electrical charge