CHONDRICHTHYES

CHARACTERISTICS

• These are fish with a skeleton made of cartilage
• Have scales and heart with chambers in series
• Also have jaws with paired fins
• They also lack ribs
• Well developed electroreceptive system

CLASSES

• This class is divided into 2 subclasses
• 1-Elasmobranchii (sharks, rays, and skates)
• 2-Holocephali(ghost fish)

HOLOCEPHALI

• Chimaeras(often called ghost fish)
• One of the oldest and most enigmatic groups of fish today
• Closest relative is the shark
• Today that are largely confined to deep water

REPROCUCTION

• The male injects the female with sperm
• Internal fertilization
• Produce few yolky eggs

CHARACTERISTICS

• They have teeth-like scales
• First fish to have paired fins
• Have 5-7 gill slits on either side
• No swim bladder
• Very good sensory system

SOME FACTS

• If sharks were able to sleep they would die from lack of oxygen
• Sharks strike blind
• Most live in saltwater but some are known to spawn and feed in freshwater rivers
• Holocephali have one gill opening and there upper jaw is fused with their skull
• They also have no teeth