Jellyfish

Scientific classification Kingdom: Phylum: Subphylum:

Animalia Cnidaria Medusozoa

Classes Cubozoa Hydrozoa Polypodiozoa Scyphozoa Staurozoa

Anatomy

Most jellyfish do not have digestive, osmoregulatory, central nervous, respiratory, or circulatory systems.

Vision Some jellyfish also have ocelli: Some species of jellyfish has 24 eyes, two of which are capable of seeing color, and four parallel brains that act in competition.

Life history Most jellyfish undergo two distinct life history stages (body forms) during their life cycle. The first is the polypoid stage and the second is the medusa. Polyps may be solitary or colonial.

Reproduction Jellyfish reproduce both sexually and asexually. Jellyfish are usually either male or female (hermaphroditic). After a growth, the polyp begins reproducing asexually by budding and, in the Scyphozoa, is called a segmenting polyp, or a scyphistoma. New scyphistomae may be produced by budding or form new, immature jellies called ephyrae.

Feeding Jellies are carnivorous, feeding on plankton, crustaceans, fish eggs, small fish and other.

Blooms

Jellyfish blooms can grow to 100,000 individuals. Bloom formation is a complex process that depends on ocean currents, nutrients, sunshine, temperature, season, prey availability, reduced predation and oxygen concentrations.

Biotechnology

In 1961, Osamu Shimomura extracted green fluorescent protein (GFP) and another bioluminescent protein, called aequorin, from the large and abundant hydromedusa Aequorea victoria, while studying photoproteins that cause bioluminescence in this species. In 2008, Shimomura, Chalfie and Tsien won the Nobel Prize in Chemistry for their work with GFP.

Toxicity Jellyfish sting their prey using nematocysts, also called cnidocysts, stinging structures located in specialized cells called cnidocytes, Contact with a jellyfish tentacle can trigger millions of nematocysts to pierce the skin and inject venom,