Coral, a hard material formed in the sea by colonies of tiny animals called coral polyps. See more »

Jellyfish, or Medusa (plural: medusae), a water-dwelling animal. It is not a fish but a cnidarian, a spineless, soft-bodied animal. See more »

Imagine trying to figure out the details of a jellyfish's life by studying the formless blob that it quickly becomes out of water. Find about about these creatures through jellyfish behavior. See more »

Portuguese Man-of-War, a floating, compound marine animal found in warm regions of all oceans. See more »

The sea anemone has a soft, muscular, cylinder-shaped stalk with a broad, circular foot at its base. See more »

For an underwater tourist, whether in a wetsuit or in front of a TV, a major attraction is a coral reef, an amazing ecosystem inhabited by myriad colorful marine creatures. Unfortunately, coral reefs are in danger of disappearing unless immediate steps are taken to preserve this natural wonder. Take this quiz to learn more about what needs to be done. See more »

The jellyfish is an unusual and fascinating marine animal. Despite its semi-transparent, gelatinous appearance the jellyfish has a painful, venomous sting if you come into contact with one of its tentacles. Take this quiz and learn more about this unique sea creature. See more »

Cnidarian, or, Coelenterate, an animal of the phylum Cnidaria, or Coelenterata. The phylum includes the corals, hydras, jellyfish, Portuguese man-of-war, and sea anemones. See more »

You're going on vacation to a place where jelly fish stings are a common occurrence and you want to know how to treat a jellyfish sting. This article will tell you how to treat a jellyfish sting. See more »

Hydra, a genus of small, freshwater polyps. The hydra is one of the simplest forms of many-celled animals. See more »