uncharismatic-fauna:Over the Moon for Moon JellyfishThe moon jellyfish, also known as the common jel
Over the Moon for Moon Jellyfish
The moon jellyfish, also known as the common jellyfish (Aurelia aurita) is a species of jellyfish found in every ocean but the Arctic. There are many species of moon jellies within the genus Aurelia, and most are functionally very similar. A. aurita are especially common among the coasts of North and South America and Australia, where they frequently wash up on beaches. They prefer warmer shallow waters around 18C, and require a salt content of at least 0.6%, although they can survive in a wide range of temperatures and salinity, and have been found as deep as 1,000m.
As jellyfish, A. aurita have no internal organs and exhibit radial symmetry, or symmetry around a central axis. The outer bell is transparent, ranging from 10 to 60 cm across. This bell also acts as a membrane through which moon jellyfish absorb oxygen, digest food, and move their bodies. Beneath the bell are distinct, colored veins which act as a reproductive organ. Most moon jellyfish have 4, but some individuals can have more. Small, non-stinging tentacles line the outer bell, and on the underside are 4 arms which stun and collect prey such as plankton, copepods, mollusks, fish larvae, and smaller jellyfish. Although they posess no caloric value, they have high amounts of fatty acids which makes them prime prey for seabirds, turtles, fish, and larger jellyfish.
Most moon jellyfish only live 2 years in the wild, though in captivity they can live up to 25 years. They reproduce sexually, although they exhibit no courtship behaviors. Male A. aurita release their sperm into the water, where they are carried by currents into the gastric pouch of female jellyfish and fertilize their eggs. These eggs are then re-released into the water. After 10 days the eggs hatch into a larval stage called a planula which settles onto the ocean floor and form polyps. These polyps can form buds that break off and form individual jellyfish through a process called strobulation. The whole process takes about 4-6 months, and usually begins in the summer when most mating occurs. However, A. aurita is capable of reproducing year-round and will do so whenever conditions are good.
Conservation status: The moon jellyfish has not been rated by the IUCN. However, in many places it is considered invasive; when resources are plentiful, populations can explode leading to diminished resources for other animals and increased bacteria levels in the water.
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Sun, 17 Apr 2022 20:58:26
