Marrus orthocanna species of pelagic siphonophore, a colonial animal composed of a complex arrangement of zooids, some of which are polyps and some medusae. Swimming independently in the mid-ocean, it lives in the Arctic and other cold, deep waters. It is a colonial creature that is born from a single egg which is fertilized. Later on, a protozoan forms that eventually grows to form more duplicating members of the colony. It belongs to the order Siphonophorae and the genus Marrus, which also includes M. antarcticus, M. claudanielis, and M. orthocannoides.
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CarnivoreA carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of a...
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OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
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starts withLike other siphonophores, Marrus orthocanna is a colony composed of a number of specialised zooids linked together by a long stem. They have different functions such as locomotion, capturing prey, waste removal, and reproduction. At the front is the pneumatophore, an orange-colored, gas-filled float, the largest of which can reach estimated sizes of 5-10 centimeters in diameter . Behind this is the nectosome, a region where there are a number of translucent nectophores with red, unlooped radial canals. These are bell-shaped medusae specialised for locomotion. When they contract, water is expelled which causes the colony to move. The coordinations of the medusae contractions enable the organism to swim forwards, sidewards, or backwards. The remaining region is the siphosome. Most of the zooids here are polyps, specialised for collecting food. They do this for the whole colony, spreading their single long tentacles in the water to snare prey. There are also stinging cells that release munitions of toxins that kills or paralyzes the prey. Other zooids in this region undertake digestion and assimilation of food items. Reproductive medusae are found among the polyps in the siphosome and also various other specialised zooids. The various forms are all arranged in a repeating pattern. The main foods of this organism are decapods, krill and other smaller crustaceans.
Marrus orthocanna occurs pelagically in the mesopelagic zone of the Arctic Ocean, the north west Pacific Ocean, the Bering Sea, the Sea of Okhotsk, the north Atlantic Ocean and the Mediterranean Sea. It is found at depths ranging between 200 and 800 m (660 and 2,620 ft). The greatest depth at which it has been observed is about 2,000 m (6,600 ft). At these depths the temperature is about 4 °C (39 °F), hardly any light penetrates from the surface and human observation is limited to what can be seen from submersible craft.
Like most other siphonophores, pelagic siphonophores are active swimmers. When its bell-shaped echo is contracted, water is pushed out causing the flock to move. The medusa's contractions are coordinated to allow the animal to swim forward, sideways, or backward. ". It belongs to the family Agalmatidae, they can be found in the deep ocean waters of the Pacific and Atlantic Oceans, and they have asexual reproduction.
Marrus orthocanna can reach lengths of 2-3 meters long and the tentacles can extend fifty centimeters on either side. It moves forward intermittently before pausing to put out its "fishing lines", ready to ensnare passing creatures. It is a carnivore whose diet is thought to consist mainly of small crustaceans such as decapods, krill, copepods and mysids.
This colonial animal arises from a single fertilised egg. The protozooid that develops from this subsequently buds to form the other members of the colony which are thus genetically identical. The protozooid first thins and elongates, the middle section becoming the stem of the colony. The pneumatophore forms at the opposite end to the mouth. Next a growth zone on the thin stem forms and budding occurs with the formation of the nectophores. As the stem continues lengthening, further zooids develop above these. Another growth zone sees the development of the siphosome and the continuing elongation of the stem carries these zooids down with it. The division of labor among the zooids is an evolutionary advance in the constant struggle for existence in the deep sea. Such organisms as Marrus orthocanna blur the boundaries between the individual polyp and the whole colonial organism; each cannot exist without the other.
