Moon Jellyfish are easily recognizable by the pattern of four joined circles on the top of the jelly fish created by its gonads which are visible through the transparent bell.
They are single sex organisms being either male or female.
They consist mainly of water.
Their food is Plankton, including small shrimps, fish eggs and other floating larvae.
They are found across the world and have a wide range of temperature tolerance from 6 to 31 °C.
They feed on plankton and grow up to 40 centimeters in width.
The adult and larvae of Aurelia have nematocysts or stinging cells to capture prey and also to protect themselves from predators.
The animal lacks any respiratory, excretory, and circulatory systems.
Respiration occurs by diffusion across the cell wall of the organism.
As the oxygen rate in the ambient water drops so the jelly drops its rate of respiration.
They have a subumbrellar nerve net within the structure that is responsible for controlling contractions in the coronal muscle in the bell that allow it to swim.
The moon jelly has rhopalial centers, which allow it to control the pulsations of the coronal muscle.
They swim horizontally and tend to stay near the surface.
The adult has a has an umbrella margin membrane and tentacles that are attached to the bottom of the membrane.
A wide variety of predators eat the moon jelly, ranging from fishes, turtles and birds.
They probably live for about six months in the wild but in captivity under ideal conditions can live for several years.
The eggs are fertilized in the female when she ingests floating sperm given out by a male.
The eggs develop into larvae that free float until they anchor onto a substrate.
The larvae grow into an organism that resembles an anemone which splits up into organisms that grow into the adult.
See the moon jellyfish in action:
Moon Jellyfish are mainly kept in large commercial aquariums, but as the knowledge base on these jellyfish has expanded it has become possible to keep them in a home aquarium. It is a fairly complex technical task and depending on the ambient temperature of the specific residence, a water chiller will almost certainly be needed to keep the temperature within their preferred range. A good filtration system and carefully designed water flow are necessary. A well lit tank full of Moon Jellies can make a very attractive addition to a home.
MOON JELLYFISH BLOOMS
Occasionally when conditions are right moon jellyfish congregate in large numbers, a so called bloom. One of these blooms can be seen in the video below which was filmed in Dar es Salaam , Tanzania.