This video was taken in Monterey Bay Aquarium, USA
The Pacific sea nettle, Chrysaora fuscescens which lives in the Pacific Ocean is a free-floating, large jellyfish with a bell of up to about 30-50 cm across in diameter. It has four long oral arms surrounding its mouth. Sea nettles have bright distinctive colors which make them a popular organism in public aquaria especially they are relatively easy establishment and maintenance. Even though sea nettle spends most of their time passively floating on water surface, they are capable to swim against currents.
Distribution: The Pacific Sea Nettle, Chrysaora fuscescens is commonly found along the coasts of Oregon and northern California, flourishing in late summer and fall. The significant abundance of the sea nettle in the recent years has been claimed to be due to climate changes and/or human activities in the coastal regions.
Feeding behavior: Sea nettle feeds on a wide variety of zooplankton, crustaceans, pelagic snails, other jellyfish, small fish as well as their eggs and larvae. Case studies show that when sea nettles are found in high densities, they may negatively affect fish populations and they may also become nuisances to fisherman by clogging up fishing nets.
Sea nettles are carnivore organisms. As their prey passes by and brushes up against their tentacles, thousands of nematocysts are released, launching pointed stingers which release a paralyzing toxin into the prey which are transported by the oral arms into the sea nettle’s mouth for digestion.
Reproduction: Sea nettle is capable of both sexual and asexual reproduction. Its life cycle begins by the fertilization of female’s eggs through catching the sperm released by the males. Afterwards, fertilized eggs are hold in female’s mouth attached to her oral arms. As fertilized eggs grow into flat bean-shaped planula and then after they grow into flower-shaped polyps whereas they are released into the ocean where they attach themselves to a solid surface and undergo metamorphosis as they grow, developing a bell, arms, and tentacles until it is a fully formed medusa.
Risks: As sea nettles use their stingers in capturing and paralyzing their prey, they may also sting human who comes in contact with them. Such stings may cause considerable pain, irritation and discomfort. However, these stings rarely require medical attention.
References: Wikipedia and Encyclopedia of life
