25.3 A Closer Look at Bony Fish
KEY CONCEPT
Bony fish include ray-finned and lobe-finned fish.
25.3 A Closer Look at Bony Fish
Ray-finned fish have a fan of bones in their fins.
• Ray-finned fish have fins supported by a fan-shaped array
of bones.
– embedded in a thin layer of skin and connective tissue
– light, collapsible, and easy to move
25.3 A Closer Look at Bony Fish
• Ray-finned fish have a variety of body plans.
– long torpedo-shaped bodies (barracuda)
25.3 A Closer Look at Bony Fish
• Ray-finned fish have a variety of body plans.
– flattened bodies (plaice)
25.3 A Closer Look at Bony Fish
• Ray-finned fish have a variety of body plans.
– elaborate camouflage (sea dragon)
25.3 A Closer Look at Bony Fish
• A swim bladder helps a fish float higher or lower in the
water.
swim bladder
25.3 A Closer Look at Bony Fish
• Some ray-finned fish have both lungs and gills.
– can breathe air and survive out of water for several
hours at a time
– example: bichir found in West Africa
25.3 A Closer Look at Bony Fish
Lobe-finned fish have paired rounded fins supported by a
single bone.
• Lobe-fins are paired pectoral and pelvic fins that are round
in shape.
– not as maneuverable as ray-fins
– able to support weight
lobe fin
25.3 A Closer Look at Bony Fish
• Only seven species of lobe-finned fish exist today.
– coelacanths
– lungfish