Benthic Communities

living along the

bottom of the ocean

Benthic Communities

• Coral Reefs

Coral Reefs

• Corals– Are animals (Cnidarians)– Small (ant-sized) polyps live in large colonies– Hermatypic corals secret a calcium carbonate

skeleton…the reef

Coral Reefs

• Zooxanthellae– Dinoflagellate that lives within the coral polyp– A mutualism– Algae provide food, speeds up calcium

carbonate deposition & get nutrients in return

Coral Reefs

• Hermatypic Coral’s ideal habitat is 5-10 m (16-33 ft) depth & temperatures warmer than 18-21oC (64-70oF)

Fig. 14-12, p. 294

Coral Reefs

• Reefs support a large diversity of other organisms– Home to 25% of the world’s marine species