Some of the animals that live in the photic zone, also called the epipelagic or sunlight zone, include fish, dolphins, whales, seals and sharks. Zooplankton, which are tiny floating creatures, are also found in this zone.
The photic zone is the division of the ocean with the most abundant number of marine animals. Light penetrates the water and allows the phytoplankton algae, which are minuscule marine plants, to carry out photosynthesis and produce food. Phytoplankton are an important part of the food chain, as they serve as a primary food source for zooplankton and small fish that become prey to bigger sea animals. The marine life below the photic zone mainly relies on detritus that falls from the photic zone.
Below the photic zone is the mesopelagic zone, or twilight zone, where light is extremely scarce. This part of the ocean has plenty of bioluminescent animals that are capable of producing light, such as the ctenophore and the Firefly squid. Food supply is limited in the mesopelagic zone, which is why animals sometimes swim to the photic zone at night to search for food. Many animals in the twilight zone can feed on much larger animals using their sharp teeth and stomachs that are capable of expanding.