Moon Jellyfish 🌙 (10 Facts You Never Knew)

Technically speaking, the name moon jellyfish applies to many different species. These jellyfish species are almost identical as adults, which is known as the Medusa stage. They have a round, moon-like, translucent body and obvious horseshoe-shaped gonads. Some of their names include the saucer jelly, the brown-banded moon jelly, and the southern moon jelly. The scientific name for members of the moon jellyfish genus means golden. This is in reference to their gold-colored younger life stages. Their babies are golden. A jellyfish bloom is when hundreds of jellyfish occur in a single area. This usually happens when water is warmer than normal, thus causing the jellyfish to reach reproductive maturity more quickly. In some cases, moon jellyfish blooms have clogged power plant operations to the point that they've caused more than 30% of power loss across affected cities. Moon jellyfish can swim, but they don't swim to move sideways through the water. Instead, these jellyfish aim to orient themselves towards the water's surface. They swim horizontally. Keeping their bell facing the waves means their tentacles hang down to easily catch food. The amount of salt in the water helps determine the shape of a moon jellyfish's bell. These cnidarians can swim in brackish water. However, in this lower salinity habitat, the jellyfish have a more flattened bell. In saltier water, their bell is more curved. Moon jellyfish can handle such a wide range of water salinity that they can survive in almost freshwater. If a water system's salt content is 0.6% or above, and has all the other necessary ingredients for jellyfish life, moon jellyfish can live there. For reference, most of the world's oceans are more than 3% salt. Moon jellyfish have eight ropalia, which are sensory centers positioned around their bell. These are believed to sense both light and gravity. When it's sunny out, moon jellyfish are more likely to position themselves towards the water's surface, where the light is. They're considered light-sensitive animals. The moon jellyfish's mouth, which is also its anus, sits on the top of a stalk called the manubrium, which means handle. This structure is also present in humans, however, it's located on our sternum. Moon jellyfish are some of the most well-known jellyfish, mainly due to the fact that they are often housed in aquariums. They were first documented to be raised in captive care in Japan. Moon jellyfish tentacles, which line the edges of the animal's bell and are far shorter than the tentacles in other jellyfish species, are retractable, like a cat's claws. You've probably also heard that moon jellyfish change color based on what they eat, and have actually been to space. But if you weren't aware of these facts, you can learn all about them and more in our full moon jellyfish episode. There's a card on screen you can click right now. Go ahead, click it. There's lots to learn. And thanks for watching Animal Fact Files.