Chondrichthyes {cartilaginous fish}| include shark, skate, stingray, and electric ray. Sharks are fast, but others are slow. Cartilaginous fish live in ocean. They have cartilage skeletons. They have paired jaws. They have two fin pairs. They have scaly skin. They have five to seven gill pairs, which send water from mouth out gill slits. They have teeth that are large scales. They have motor maps in optic tecta. They represent sensations in midbrain.
Skates {skate} have wing-like pectoral fins and are flat diamond-shaped bottom feeders.
Rays {ray, fish} have wing-like pectoral fins and are flat and diamond-shaped.
Torpediniformes {electric ray} has electric organs on head sides and stays near bottom.
Tropical rays {manta ray} can be very large, pelagic, and plankton and small-fish eaters.
Rays {sawfish} can have sharp teeth on long flat snouts.
Dasyatidae {stingray} has long tail with one or more spines with poison. Spines are modified dorsal fin rays.
Sharks {shark} are carnivorous and have heterocercal caudal fins, tough skin, and small scales.
Large northern sharks {basking shark} can be plankton eaters and swim slowly at sea surface.
Tropical sharks {hammerhead shark} can be medium-size, be live bearing, and have flat bar-shaped heads with eyes at ends.
Outline of Knowledge Database Home Page
Description of Outline of Knowledge Database
Date Modified: 2022.0225