Class Chondricthyes Flashcards
Class Chondricthyes
Common name?
Rays, sharks, skates
Class Chondricthyes
Skeleton type?
Cartilaginous
Class Chondricthyes
Number of heart chambers?
2 chambers
1 Atrium
1 Ventricle
Class Chondricthyes
How do they control body temperature
Ectothermic - control body temperature behaviorally
Endothermic
Control body temperature physiologically
Class Chondricthyes
Placoid scale characteristics?
Modified?
Stratified squamous epithelium
Shed constantly
Some are modified into teeth
Class Chondricthyes
Gas exchange structure?
Gills
Class Chondricthyes
Reproduction type?
Internal fertilization
Class Chondricthyes
Ovoviviparous
Retain embryos in the female’s body
No placenta
Class Chondricthyes
Oviparous
Lay eggs
Class Chondricthyes
Viviparous
Retain embryos and transfer nutrients via placenta
Class Chondricthyes
Body form of sharks is same for 100,000,000 years
Stabilizing selection
Class Chondricthyes
Heterocercal tail
Spinal cord in dorsal lobe of tail
Class Chondricthyes
Lack:
Swim bladder for buoyancy
Class Chondricthyes
How do they stay buoyant?
Retain low density oils