Katherine Wallis/ Shutterstock There are some 3,600 species of hydrozoans. These are typically smaller than scyphozoan jellyfish. The polyp stage of their lives is usually more conspicuous than the ...

It then settles on the seafloor as a blob-like cyst. Over the next 24-36 hours, this blob develops into a new polyp - the jellyfish's previous life stage - and after maturing, medusae bud off. This ...

And one hydrozoan, the immortal jellyfish (Turritopsis dohrnii), seen here in a water drop, has a life cycle that skips death: It reverts from a medusa back to a polyp. How, no one knows.

all provides a perfect infrastructure for the juvenile form of the jellyfish, a polyp, to attach and grow, said Steven Haddock, a senior scientist at the Monterey Bay Aquarium Research Institute.

Jellyfish are known for drifting to and fro at the whim of ocean currents—but not all species are so passive. The millions of golden jellyfish that pack Palau’s Jellyfish Lake spend much of ...

When animals have a slow metabolic rate, they do not age but rather have a prolonged life. Resistance to diseases and genetics are also factors that can contribute to the longevity of an animal.

On completion of the investigation Dr. Ranatunga identified the creature as a rare freshwater jellyfish exhibiting a medusa stage in its life cycle. Dr. Ranathunga said the creature begins its life ...

This colorful jellyfish is not one organism but a colony of four kinds of polyp. The stinging cells on the tentacles with which it fishes secrete a substance that is almost as toxic as cobra venom ...

Jellies: Go with the Flow brings a new, custom-built, 1,700-square-foot permanent expansion to the Newport Aquarium. The ...

The integral jellyfish is a new hydrozoan species found ... Sugimoto was also able to successfully raise the species from the polyp stage, an early phase of development, marking the first time ...