- The bell (body) is bowl-shaped and white, with a radial pattern of 16 purple stripes on the bell of the adult.
- Bell can be up to 3 feet in diameter and tentacles can be as long as 25 feet.
- The tentacles consist typically of eight marginal long dark arms, and four central frilly pink oral arms.
- The four frilly oral arms may be missing in older individuals.
- Juveniles lack the purple stripes on the bell, and their bell is pale pinkish in coloration.
- Juveniles’ tentacles are dark reddish instead of purple.
- Live off the coast of California, often near Monterey Bay.
- Primarily pelagic, in nearshore open waters.
- Their lifecycle was not understood until 2008, when scientists observed they have both a sexual and asexual phase.
- In the sexual stage, male adults transfer strands of sperm from the tips of their oral arms to the tips of the female’s oral arms and tentacles.
- The female transfers the sperm to her gastrovascular cavity and fertilizes the eggs.
- She then moves the eggs to her oral arms where they are brooded and become ciliated larvae.
- These larvae break off and swim to a suitable hard surface that they attach to upside-down.
- This starts the asexual stage. These upside-down larvae morph into polyps, that grow tentacles to feed with.
- These polyps then bud off genetically identical clones one at a time when conditions are not ideal.
- When conditions are ideal, the polyps can also make strobila, which are stacks of tiny identical clones, all just a quarter of inch in diameter, that swim off together.
- The strobila grow into the adult form in 2-3 months.
- Zooplankton, including copepods, larval fish, ctenophores, salps, other jellies, and fish eggs.
- Primarily preyed upon by leatherback turtles.
- Also eaten by sunfish and sea turtles.
- They are also known as the purple-striped sea nettle.
- They are often found with young slender crabs hitching a ride in the jelly’s bell. The crabs get a free ride on the jelly, and the crabs eat parasitic amphipods that damage the jelly.
- They have a strong painful sting, but it is not fatal.
Sources: Monterey Bay Aquarium; National Aquarium; Graham et al. 2010; Aquarium of the Pacific; Scripps Zooplankton Guide
Photo: Tracy Clark