1. Osteichthyes
The Bony Fish

2. Class Osteichthyes Characterized by having: Bone in their skeleton
An operculum covering the gill openings
A swimbladder or lungs
True scales
Paired fins
Homocercal tail (Exception lungfish – diphycercal)
Mouth terminal
Two chambered heart
Sexes separate (Sex reversal in some)
Fertilization external for most
Excrete ammonia

3. Class Osteichthyes
The bony fishes are the most diverse class of fish. ~24,000 species
Osteichthyes are divided into two subclasses
The lobe-finned fish (Sarcopterygians)
The ray-finned fish (Actinopterygians).
*Most modern fish are members of the ray-finned, Teleost subdivision.

6. Sarcopterygians
Sarcopterygians are the fish most closely related to modern amphibians, reptiles, birds, and mammals
This subclass includes the lungfish and coelacanth. Coelacanth were thought to have become extinct at about the same time as the dinosaurs, until a live specimen was found in 1938

7. Sarcopterygians Characteristics: Muscular lobe associated with fins
Have lungs for gas exchange
Live in areas with seasonal droughts
Can breathe air if water stagnates
Cannot withstand desiccation
Burrow in the mud
Have enamel on the teeth

8. Sarcopterygians
Can survive drought by remaining in aestivation for 6 months or more
Aestivation = dormant state
After rain fills the lake or riverbed Lungfish emerge from their burrows to feed & reproduce

10. Lungfish - Found in Australia & Madagascar

11. Lungfish scales
Cosmoid scales

12. Lungfish Circulation

13. Coelacanth
                                                            

14. Actinopterygians Ray-finned fish (Fins lack muscular lobes)
Have swimbldders to regulate buoyancy
~23,900 species

15. Chondrosteans (Fresh water fish)
Include stergeons and paddlefish
Stergeon eggs make caviar

16. Caviar = Sturgeon eggs

17. Paddlefish

18. Subdivisions of Teleostei
Superorder Ostariophysi
Order Cypriniformes (minnows, carps)
Order Siluriformes (catfish)
Superorder Protacanthopterygii
Order Esociformes (pikes)
Order Osmeriformes (smelts)
Order Salmoniformes (salmon, trout, whitefish)
Superorder Paracanthopterygii
Order Gadiformes (cod, hakes, pollock)
Superorder Acanthopterygii
Order Percoidei (perches, snook, basses)
Order Pleuronectiformes (flounders, soles)
Order Perciformes (mackerel, tuna, swordfish)

19. Actinopterygians The Teleosts
Teleosts are modern day ray-finned fish
Use their fins and body wall to push against water for locomotion
Some secrete mucus to reduce friction
Most teleosts are carnivores swallowing prey whole
Herring & paddlefish are filter feeders
Teleosts have pyloric ceca (outpockets in the small intestine to increase absorption)

20. Ganoid Fish Scales Found on non-teleost bony fishes
Usually diamond shaped bony scales
“Heavy armor”

21. Cycloid Fish scales
Found on teleost fishes
Light, thin, & flexible

22. Ctenoid Fish Scales Teleost fishes
Have comblike ridges along the exposed edge to reduce friction (drag)

23. Myomeres

25. Swimming mechanics Thrust- force in animal's direction
Lift- force opposite in right angles to the thrust 
Drag- force opposite the direction of movement

26. Swimming mechanics Yaw – side to side movement of head
Pitch – up and down movement of head