Chondrichthyes

Chondrichthyes are the cartilaginous fish of the ocean. This group of animals has 1,000 species and includes sharks, rays, and skates. These fish have skeletons made out of cartilage instead of true bones. This makes their skeleton more flexible. Chondrichthyes have hard scales, paired fins and have 5-7 gills. They can both give birth to live young or lay eggs. For sharks, they move by moving their head and tail back and forth, their fins are for stabilization and steering. (1,4)

Species 1:

Horn Shark - Heterodontus francisci (3)

Habitat: Horn Sharks live on the seafloor in shallow water. They tend to hide in the rocks and crevices. (3)

Niche: Horn Sharks are very helpful to kelp forests because one of the main things they eat is sea urchins. Like sea otters, horn sharks help control the urchin population so that the kelp forest isn't in danger of being eaten. (3)

Adaptations: The horn sharks have dark, muddy coloration which helps them blend into the rocky sea floor where they hide. (3)