Jellyfish restored: they eat fish eggs and juvenile fish, and compete with fish for food, preventing fish stocks from recovering. Some small fish are immune to the stings of the jellyfish and live among the tentacles, serving as bait in a fish trap; they are safe from potential predators and are able to share in the fish caught by the jellyfish. The cannonball jellyfish has a symbiotic relationship with ten different species of fish, and with the longnose spider crab, which lives inside the bell, sharing the jellyfish's food and nibbling its tissues. Jellyfish form large masses or blooms in certain
Jellyfish circular tanks to avoid trapping specimens in corners. They have a live "Jelly Cam". The outflow is spread out over a large surface area and the inflow enters as a sheet of water in front of the outflow, so the jellyfish do not get sucked into it. As of 2009, jellyfish were becoming popular in home aquariums, where they require similar equipment. Jellyfish are armed with nematocysts. Contact with a jellyfish tentacle can trigger millions of nematocysts to pierce the skin and inject venom, but only some species' venom causes an adverse reaction in humans. The effects of stings range