Bow Down to the Crown Jellyfish
The crown jellyfish (Cephea cephea), also known as the cauliflower jellyfish, is a species of jellyfish found primarily in the open waters of the Indo-Pacific Ocean, from the surface up to a depth of 915 m (3,000 ft). They spend most of the day in deeper waters, and then rise to the surface at night to feed.
Like most jellyfish, C. cephea is a filter feeder. The bulk of their prey consists of algae, shrimp, plankton, invertebrate eggs and invertebrate larvae. Although they are venomous, they are not considered a threat to humans. Rather, it's venom is designed to deter its natural predator, sea turtles.
The crown jellyfish is named for its distinctive appearance. The 'bell', or umbrella is bright purple, up to 60 cm (23 in) across, and situated in the middle is a bulb of multiple protruding round spikes. Beneath is a cauliflower-shaped mass, often white or yellow, from which the 30-40 thin tentacles descent. In addition to its bright coloring, the cauliflower jellyfish is also notable for being bioluminescent at night and in the darker depths of its range; the purpose of this light show is unclear.
C. cephea is a broadcast spawner, meaning that females and males both release their reproductive material into the open water. The fertilized eggs hatch into microscopic larvae, which then floats through the ocean for months or even years until it encounters a rock, coral, or other sedentary object. There, it grows into a structure called a polyp that filter feeds on passing plankton for another several weeks. When it gets big enough, it undergoes strobilation, in which layers peel off to become tiny jellyfish. These baby crown jellyfish grow extremely quickly, starting at only 2-3 mm (0.07-0.11 in), but grow to to 1.7 cm (0.66 in) in only a few weeks. Once they reach their adult size, they only live for 3-6 months.
Conservation status: The crown jellyfish has not been listed by the IUCN. Due to its large population size and range, it is considered stable, and may even be expanding its range due to warming oceanic waters.
Photos
Derek Keats
Alexia Pihier
