Jellyfish Jellyfish Jellyfish or sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella-shaped bells and trailing tentacles, although a few are not mobile, being anchored to the seabed by stalks. The bell can pulsate to provide propulsion and highly efficient locomotion. The tentacles are armed with stinging cells and may be used to capture prey and defend against predators. Jellyfish have a complex life cycle; the medusa is normally the sexual phase, the planula larva can
Atolla jellyfish the “alarm jelly”. It is believed that the purpose of these flashes is to attract a bigger predator than the one that was currently attacking it (Herring 2004). It is an attempt to scare the predator that is currently attacking it with a larger predator that could possibly prey on the predator attacking it. There has been evidence that "Atolla wyvillei" is threatened by shrimp (Moore,1993). A close relative of "Atolla" species, the crown jellyfish is eaten as a delicacy in Japan (Seaunseen, 2014). Atolla jellyfish Atolla wyvillei, also known as the Atolla jellyfish or Coronate medusa, is a species