chordates and fish. chordates 45,000 members must have the following dorsal nerve chord –...
TRANSCRIPT
Chordates and Fish
Chordates
• 45,000 members
Must have the following• dorsal nerve chord – vertebrae• cranium – skull• endoskeleton of bone or
cartilage
7 CLASSES of VERTEBRAE
1. Mammalia
• hair, milk young
2. Aves
• birds : feathers, hollow bones
3. Reptilia
• dry scaly skin
4. Amphibia
• permeable skin
And 3 that are FISH!
5. Agnatha
• jawless fish • lampreys and hagfish• round mouth• long eel like bodies• gills evolved to…
Lamprey video
6. Chondrichthyes
• (kahn-Drick-theeez) • sharks, skates and rays• jaws and paired fins• cartilage skeleton• unique placoid scales
7. Osteichthyes
• (Ahs-tee-Ich-theeez) • bony fish : salmon, bass, etc.• jaws• skeleton of bone• lobe (mud) or ray finned
Largest Bony Fish
Longest Bony fish
Adaptations to live and Survive in Water
• trap gas = buoyancy• Trap in organ called gas
bladder/swim bladder• regulates depth with O2, CO2 and N2
Adaptations…
• streamline shape
Adaptations…
• muscular tail : Caudal fin
Adaptations…
• paired fins : 2 dorsal and 2 pelvic
Adaptations…
• mucus = less friction
Other escape adaptations
Puffer fish
Adaptations…
• gills : gas exchange O2 in and CO2 out
Adaptations…
• lateral line system :
nerves for sensing
vibrations in water
Adaptations…
• Separate sexes • internal and external
fertilization • spawning
Fish fighting