Helmet jellyfish

Crown jellyfish ( Periphylla periphylla )

The crown jellyfish ( Periphylla periphylla ) is a glowing, red-colored deep-sea jellyfish. It belongs to the phylum Cnidaria ( cnidarians ).

Reproductive cycle

P. peripyhlla is an exception, which is very rare in the root of cnidarians. The jellyfish does not have a polyp stage and has a " holopelagischen " life cycle. The medusa is fertilized eggs in the open water and these evolve directly to the Medusa, with the development of the medusa is based solely on the high yolk of the egg. Also the stage of Ephyra larva that is released into the open water is not observed in P. periphylla.

Way of life

The jellyfish is found in depths of up to 7,000 meters and is perfectly adapted to their dark surroundings. Through the use of bioluminescence it is lit from within. The light signals are used for the jellyfish to communicate among themselves. A weight of up to one ton weighs on every square inch of the animals that live in the deep sea. At night, leaving the crown jellyfish deep-sea and floats their food, the plankton counter. With full stomachs she returns from the surface to the deep sea back. Of the secretions of the crown jellyfish other deep-water fish feed. The bright red crown jellyfish reaches a height of up to 30 centimeters. It consists of 90% water, the rest are tissue and gelatinous mass that give the animals their shape. Sit tiny sense piston between her wings flap. Through them the crown jellyfish light and dark may differ. It occurs in the fjords of Norway and the Mediterranean.

Current ecological problems

In many fjords of Norway, the crown jellyfish spreads increasingly since the 1970s. It is always more to Nahrungskonkurrentin of fish and is therefore also a threat to the fishing operation. By displacement of almost all other sea creatures, these jellyfish would actually their own basic food have robbed, but the jellyfish swarms of living. The cause is being investigated by marine biologists to Ulf Bamsted. Also not far from Bergen, in Lurefjord, the crown jellyfish has spread. The goal is to find a possible explanation for the recent mass developments. The ecology and population dynamics is investigated by Norwegian and American research groups. The ontogeny, in particular the development of pigmentation, the lighting, the food intake and sensory performance is explored in a Hamburg working group.