Blue jellyfish in Brofjorden at Sandvik 67

Underside of expanded bluefire jellyfish in Brofjorden at Sandvik 57

Sideview of contracted bluefire jellyfish in Brofjorden at Sandvik 2

''Cyanea lamarckii'', also known as the blue jellyfish or bluefire jellyfish, is a species of jellyfish in the family

Cyaneidae The Cyaneidae are a family of true jellyfish. About 20 species are in this family, including the well-known lion's mane jellyfish, lion's-mane jellyfish. Species The following species are recognized within the family Cyaneidae. Formerly, this f ...

Description

Blue jellyfish age can be identified by color of their bell. They tend to be pale in appearance when young, but mature to have a brightly purple-blue (some yellow) colored bell. Although it is similar to the

lion's mane jellyfish The lion's mane jellyfish (''Cyanea capillata'') is one of the Largest organisms#Cnidarians (Cnidaria), largest known species of jellyfish. Its range is confined to cold, boreal ecosystem, boreal waters of the Arctic Ocean, Arctic, northern Atla ...

, the blue jellyfish is not as large, and has a translucent bell. ''C. lamarckii'' has a blue or yellow tone and grows to approximately across the bell, but specimens can grow to . In

Scandinavia Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...

n seas, this species rarely grows larger than . These jellyfish drift closer to the shore to catch the large abundance of plankton with their tentacles. This jellyfish has many stinging tentacles. The four mouth arms are large with many wrinkles and ripples. The jellyfish live off a diet of

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), mea ...

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

as well as the eggs and larvae of other aquatic animals such as fish. ''Cyanea lamarkii'' use their tentacles containing

nematocysts A cnidocyte (also known as a cnidoblast) is a type of cell containing a large secretory organelle called a ''cnidocyst'', that can deliver a sting to other organisms as a way to capture prey and defend against predators. A cnidocyte explosively ...

to not only catch their prey, but to protect from predators.

Distribution

This species is found in the

pelagic zone The pelagic zone consists of the water column of the open ocean and can be further divided into regions by depth. The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the sur ...

off the west coast of

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

, the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

, the

English Channel The English Channel, also known as the Channel, is an arm of the Atlantic Ocean that separates Southern England from northern France. It links to the southern part of the North Sea by the Strait of Dover at its northeastern end. It is the busi ...

, and the

Irish Sea The Irish Sea is a body of water that separates the islands of Ireland and Great Britain. It is linked to the Celtic Sea in the south by St George's Channel and to the Inner Seas off the West Coast of Scotland in the north by the North Ch ...

, sometimes with the more common

(''Cyanea capillata''). It's also seen in Cattegat along the Swedish western coast as well as in Danish waters.

Taxonomy

The

taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

of ''Cyanea''

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

is not fully agreed upon. Some

zoologists This is a list of notable zoologists who have published names of new taxa under the International Code of Zoological Nomenclature. A * Abe – Tokiharu Abe (1911–1996) * Abeille de Perrin, Ab. – Elzéar Abeille de Perrin (1843–1910) * ...

have suggested that all species within the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

should be treated as one. However, ''Cyanea lamarckii'' exists with two other distinct taxa in at least the eastern

North Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for ...

. The species specifier originates from the French naturalist

Lamarck Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck (1 August 1744 – 18 December 1829), often known simply as Lamarck (; ), was a French naturalist, biologist, academic, and soldier. He was an early proponent of the idea that biolo ...

(Latin name form: Lamarckius).

Life cycle

The medusae bud and loosen from the mature polyps between January and March around the

British Isles The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebr ...

and southern North Sea. This occurs in a similar way to the life cycle of the

moon jellyfish ''Aurelia aurita'' (also called the common jellyfish, moon jellyfish, moon jelly or saucer jelly) is a species of the family Ulmaridae. All species in the genus are very similar, and it is difficult to identify '' Aurelia'' medusae without gene ...

. These blue jellyfish live for less than a year.

Description

Distribution

Taxonomy

Life cycle

References

Further reading