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Jellyfish


Jellyfish
Photo Information
Copyright: Robin O'Connell (roconnell) Gold Star Critiquer/Gold Note Writer [C: 155 W: 0 N: 61] (404)
Genre: Plants
Medium: Color
Date Taken: 2007
Categories: Cnidarians
Camera: Canon Powershot S80
Photo Version: Original Version
Date Submitted: 2007-12-26 14:58
Viewed: 1107
Points: 6
[Note Guidelines] Photographer's Note
This jellyfish surfaced nearshore at Gaeta Bay. The bright sunlight illuminated both the debris in the water as well as this beautiful Cnidarian.

Unlike the "Blue Bottle" (Portuguese Man-of-War) of Hawaii (see previous post), this Shiff Arms Jellyfish(Rhizostoma pulmo)is a solitary species and a true jellyfish.

More about Cnidarians:
Within the classification of the Animal Kingdom, and within the sub-Kingdom of Metazoans (organisms with tissues, organs and systems of organs with radial symmetry such as the jellyfish, anemones, hydra and corals) there is the Phylum of the Cnidarians, which is the group to which the jellyfish belong.

Within the Phylum of Cnidarians, it is possible to differentiate four large groups, each with its own characteristics. They are:

• The class of Hydrozoa.

They show the phases of polyp and jellyfish alternately. They are generally small in size and they can be colonial or solitary. The siphonophores are included in this class. They are floating colonies of polyp individuals and jellyfish with great and abundant poisonous cells for self-defence which, in certain cases, can be lethal for people. The siphonophores form complex colonies of individuals specialising in different functions; some serve as the flotation organ, others for nutrition, defence or for feeling. Among the best-known species of siphonophores, are the by-the-wind sailor (Velella spirans) or the Portuguese man of war (Physalia physalis), which can produce painful burns for bathers, and even heart failure.

• The class of Esciphozoa.

This is the group of those known as true jellyfish. They are the great marine jellyfish, normally with a very short or even non-existent polyp phase. The following belong to this class: the moon jelly (Aurelia aurita) which is very common in the Mediterranean, the Rhizostoma pulmo which inhabits the Mediterranean and the Atlantic or the fried egg jellyfish (Cotylorhiza tuberculata). Some species are luminescent, such as the purple jellyfish or mauve stinger (Pelagia noctiluca), which can be really striking on a night-time dive. Its eight stinging tentacles can reach a diameter of ten metres when spread out.

• The class of Cubozoa.

A class with few representatives that some authors group together with the esciphozoa. They inhabit the waters of tropical and sub-tropical seas. These are the so-called box jellyfish or sea wasps. They have their umbrella in the form of a cube, with four sides. They have a powerful sting and they may cause death to a person in just a few minutes if he is not treated with an antidote.

• The class of Anthozoa.

All the representatives of this class are polyps, which never adopt the jellyfish stage. It includes corals, madreporas, actinias and sea anemones. They are generally species of a beautiful colour. Some individuals live in isolation, such as the beadlet anemone (Actinia equina), some anemones and the colour tube anemone, (Cerianthus membranaceus), and others form colonies such as the corals or the red gorgonians (Paramuricea sp.).

Source: Oceana
bizsu, matatur has marked this note useful
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Critiques [Translate]

Excellent shot, Robin! Very focused and good clear shot. Reminds me of what's called an 'eggyolk' jellyfish they had on display at the Oregon Aquarium. But don't ever touch the tentacles! There's only one kind I know of that's 'stingless' and they are in a lagoon, shuttered from the rest of the world of jellyfish.

  • Great 
  • bizsu Silver Star Critiquer [C: 39 W: 0 N: 4] (196)
  • [2007-12-26 16:25]

Hi Robin,
Fantastic photo !
Good POV. Very nice colours, Super note. Congratulation.
Happy New Year !
Regards, Zsú

A perfect picture of a Rhizostoma Robin, good DOF resulted in a totally focused specimen. Uniform greenish BG is also very nice. TFS.
Mehmet

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