Jellyfish

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Jellyfish
Liocranchia valdiviae

Liocranchia valdiviae

Systematics
Trunk : Molluscs (mollusca)
Class : Cephalopods (cephalopoda)
Subclass : Octopus (coleoidea)
Superordinate : Ten-armed squid (Decabrachia)
Order : Squids (Teuthida)
Family : Jellyfish
Scientific name
Cranchiidae
Prosch , 1847

The jellyfish (Cranchiidae) are a family in the order of the squid with about 60 species.

features

The common name of the family comes from the transparent bodies of most species. The body lengths of many species range on average from ten centimeters to two meters. Compared to her big coat the double row with effect suckers occupied tentacles rather short. The shape of the eyes varies greatly from large and round to small and telescopic .

Many species are bioluminescent and have a luminous organ below their eyes. With its help, they are able to compensate for their shadow on the sea floor in shallow waters.

A swim bladder filled with ammonia lets you control your static buoyancy . Often the only recognizable organ is a cigar-shaped digestive gland, which in cephalopods is the equivalent of the liver of mammals. Usually this is held in a vertical position to minimize its silhouette; sometimes there is also a light organ on the underside.

The body shape of many species differs greatly in the individual growth phases and therefore makes a clear assignment difficult.

Way of life

Many species live on the surface or in intermediate depths of the open oceans. As with most squids, the juveniles of many jellyfish species also live on the surface of the water and only penetrate deeper waters after a while. Some species live up to two kilometers deep. In the light-flooded surface water, their transparency offers them protection.

Jellyfish are not important for fishing .

Systematics

The gall squid are classified into two subfamilies with a total of 15 and 16 genera . The status of the genus Drechselia is still controversial and needs further investigation.

literature

  • Mark Norman : Cephalopods: A World Guide . Hackenheim, ConchBooks 2000; Page 156

Web links

Commons : Cranchiidae  - Collection of images, videos and audio files