Sea Nettles are one of the most popular exhibits in public aquariums. Their movement looks like sheer poetry in motion. Sea nettles inhabit the Atlantic (Chrysaora fuscescens), Pacific Ocean (Chrysaora quinquecirrha). Depending on the species, they grow anywhere from 6 inches all the way up to three feet in diameter. Typically their trailing tentacles reach over twice that length. The Pacific is the larger of the two species. This jellyfish was successfully cultivated in Monterey California less than two decades ago. This was the first time they had ever been bred in captivity. Monterey was the first aquarium to exhibit jellyfish to the public.
A sea nettle’s sting in very often deadly to proportionately sized prey. Their sting is rated from moderate to severe in regards to human interaction. Their venom is not lethal unless it is the result of an allergic reaction. They will cause moderate discomfort levels in people that are not overly sensitive to jellyfish toxins. Toxicology reports on Japanese sea nettles (Chrysaora melanaster) indicate more serious reactions.
Sea nettle bells are semi-transparent. Pacific sea nettles can either be white and opaque in appearance or striped. Striped bells are typically reddish-brown adorned with small white dots. The species native to the Atlantic is generally a pale shade of pink or yellow and may also be striped. Long, flowing tentacles extend from the circumference of the bell generally stretching 2-3 times the bell’s diameter. Sea nettles have a single mouth opening on the underside of their bell. In addition to their mouth, they have a long, lace-like oral arm in the center of their bell that transports their food to their mouth opening.
Unlike most jellyfish, sea nettles are very good swimmers and swim continuously.They seem to prefer swimming against the current which is why they are so often seen swimming upside down in most pictures.
It should be noted that Pacific sea nettles are the larger of the two species. There are not any readily fabricated aquariums large enough to house them. They will require a custom built set up. You should also be aware that these jellies are indigenous to colder waters, from northern California to Alaska. They are accustomed to water temperatures in the mid-fifty degree range. Your jellyfish aquarium will require a water chiller to accommodate their environmental needs.