Moon Jellyfish

This photo was taken in 2011 at AQWA Aquarium in Perth, Australia. Pictured is a moon jellyfish, a common jellyfish belonging to the genus Aurelia. Ten species, including the moon jellyfish, in the genus Aurelia are so similar that it is impossible to identify differences without genetic sampling. Moon jellyfish lack respiratory, excretory, and circulatory systems. They feed on plankton, using their tentacles to trap and paralyze the small animals while small cilia move the food into the jellyfish's gastrovascular cavity. Little is known about the vitamin requirements of jellyfish, but since they produce digestive enzymes it is reasoned that they can process fats, carbohydrates, and proteins just as most animals can.

Grey Nurse Shark

This photo was taken in 2011 at AQWA Aquarium in Perth, Australia. The grey nurse shark is known as a sand tiger shark in the U.S. and a spotted ragged-tooth shark in Africa. They are the most commonly kept aquarium sharks due to their ability to survive well in captivity. Grey nurse sharks are fierce looking because of their jagged teeth that protrude from their mouths, but they are relatively harmless and will only attack if provoked. The grey nurse shark gulps air into it's stomach to maintain buoyancy. Out of all known shark species, none are known to do this besides the grey nurse.