Praya dubia
Encyclopedia
Praya dubia, or the Giant Siphonophore, is a deep sea
organism
(700 m to 1000 m below sea level
), a member of the Hydrozoa
. With a body length of 40–50m, Praya dubia is one of the largest invertebrate
s. It is actually a colony made up of numerous small connected individuals, each with a specific function, such as feeding, attack and defense.
Sometimes referred to as the swimming bell, Praya dubia has a dome-like section (the nectosome) as well as long thin sensory and stinging organs (the siphosome). Its body is whitish and transparent. Praya dubia attracts its prey by blue bioluminescent light
. The sting will cause paralysis and/or death.
When raised to the surface these animals burst, as they have a hydrostatic skeleton
that normally experiences an average pressure of above 0.47 tons/cm2. Praya dubia has been known since the nineteenth century, but its length was discovered only after the Monterey Bay Aquarium Research Institute
undertook a systematic study of the water column in 1987.
Deep sea
The deep sea, or deep layer, is the lowest layer in the ocean, existing below the thermocline and above the seabed, at a depth of 1000 fathoms or more. Little or no light penetrates this part of the ocean and most of the organisms that live there rely for subsistence on falling organic matter...
organism
Organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
(700 m to 1000 m below sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...
), a member of the Hydrozoa
Hydrozoa
Hydrozoa are a taxonomic class of very small, predatory animals which can be solitary or colonial and which mostly live in saltwater. A few genera within this class live in freshwater...
. With a body length of 40–50m, Praya dubia is one of the largest invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s. It is actually a colony made up of numerous small connected individuals, each with a specific function, such as feeding, attack and defense.
Sometimes referred to as the swimming bell, Praya dubia has a dome-like section (the nectosome) as well as long thin sensory and stinging organs (the siphosome). Its body is whitish and transparent. Praya dubia attracts its prey by blue bioluminescent light
Bioluminescence
Bioluminescence is the production and emission of light by a living organism. Its name is a hybrid word, originating from the Greek bios for "living" and the Latin lumen "light". Bioluminescence is a naturally occurring form of chemiluminescence where energy is released by a chemical reaction in...
. The sting will cause paralysis and/or death.
When raised to the surface these animals burst, as they have a hydrostatic skeleton
Hydrostatic skeleton
A hydrostatic skeleton or hydroskeleton is a structure found in many cold-blooded organisms and soft-bodied animals consisting of a fluid-filled cavity, the coelom, surrounded by muscles. The pressure of the fluid and action of the surrounding circular and longitudinal muscles are used to change an...
that normally experiences an average pressure of above 0.47 tons/cm2. Praya dubia has been known since the nineteenth century, but its length was discovered only after the Monterey Bay Aquarium Research Institute
Monterey Bay Aquarium Research Institute
The Monterey Bay Aquarium Research Institute is a not-for-profit oceanographic research center in Moss Landing, California affiliated with the Monterey Bay Aquarium. It was founded in 1987 by David Packard of Hewlett-Packard fame...
undertook a systematic study of the water column in 1987.