Habitat of the Moon Jellyfish

Countries &Oceans

• Moon jellyfish are found throughout the world, including in the Pacific, Indian and Atlantic oceans. However, as reported by the BBC website, these jellyfish are most common in the waters near the North American continent and in European waters. The moon jellyfish and the other, near-identical, species within the Aurelia genus have a presence in almost every one of the Earth's oceans.

Types of Environment

• Moon jellyfish generally prefer to inhabit coastal waters, living in both inshore seas and oceans. This means that they're found in environments such as coastal bays and estuaries, and humans may well encounter moon jellyfish washed up on beaches and in harbors. The reason why moon jellyfish stick to coastal waters, as opposed to inhabiting deeper areas of ocean, is that they need shallow areas for their young to survive. Moon jellyfish are also weak swimmers, and thus tend to be found on coastlines, dragged in by the tide.

Temperatures

• Moon jellyfish can survive across a whole range of water temperatures. These jellyfish do prefer waters between 48 and 66 degrees Fahrenheit, but they will also thrive in very cold waters, including those with a temperature down to 21 degrees Fahrenheit. In warmer parts of the world, such as in the tropics, moon jellyfish are also found in water temperatures of up to 86 degrees Fahrenheit.

Salinity

• The salinity of water is its saltiness, and is measured on the Practical Salinity Scale, or PSS. As with temperature, moon jellyfish are adept at thriving in a range of areas of varying salinity. For example, although the moon jellyfish's preferred environment has a salinity of 23 PPS or above, these jellyfish can survive in areas where the salinity is as low as 3 PPS. Salinity does, however, affect the jellyfish's body; living in an environment of low salinity will reduce the curvature of the moon jellyfish's bell, in other words the shape of its body.

Danger to Swimmers

• Because they have a tendency to become washed up on shorelines in large numbers, moon jellyfish are frequently encountered by humans on beaches or paddling in shallow waters. Moon jellyfish can be dangerous, as their tentacles are armed with poisonous sting cells. This poison isn't fatal to humans but can cause soreness and pain.