moon jelly

Description:

Aurelia aurita (moon jelly, moon jellyfish, common jellyfish, saucer jelly) is one of a group of more than ten morphologically nearly identical jellyfish species in the genus Aurelia.[1] In general, it is nearly impossible to identify Aurelia medusae without genetic sampling, so most of what follows about Aurelia aurita, could equally be applied to any species of the genus. The medusa is translucent, usually about 25–40 cm in diameter, and can be recognized by its four horseshoe-shaped gonads that are easily seen through the top of the bell. It feeds by collecting medusae, plankton and mollusks with its mucusy bell nematocyst-laden tentacles and bringing the prey into its body for digestion, but is capable of only limited motion; like other jellies it primarily drifts with the current, even when it is swimming.

Habitat:

Genus Aurelia is found throughout most of the world's oceans, from the tropics to as far north as latitude 70°N and as far south as 40°S.[2] The species Aurelia aurita, whose distribution has been confirmed by Michael Dawson using genetic analysis, is found along the eastern Atlantic coast of Northern Europe and the western Atlantic coast of North America in New England and Eastern Canada.[3] In general, Aurelia is an inshore genus that can be found in estuaries and harbors.[4] It lives in ocean water temperatures ranging from 6 °C to 31 °C; with optimum temperatures of 9 °C to 19 °C. A. aurita prefers temperate seas with consistent currents. It has been found in waters with salinity as low as 6 parts per thousand

Notes:

Hongkong Ocean Theater