Grimpoteuthis

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Grimpoteuthis
Grimpoteuthis discoveryi.jpg
Grimpoteuthis discoveryi
Scientific classification e
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Octopoda
Family: Opisthoteuthidae
Genus: Grimpoteuthis
Robson, 1932
Species

14, see text

Grimpoteuthis is a genus of pelagic umbrella octopus that live in the deep sea. Prominent ear-like fins protrude from the mantle just above their lateral eyes. They have a U or V shaped shell in their mantle which gives them a bell shaped appearance. Some species are short, squat and yellow, while others resemble a jellyfish with one, big, brown, walking shoe. Some have suckers, in addition to spines, on all 8 webbed tentacles while others look like a regular octopus with the addition of blue or other colored "ears". These octopuses are commonly nicknamed "Dumbo octopuses" or "Dumbo octopods" in reference to how the ear-like fins protruding from the top of their head-like bodies resemble the ears of Walt Disney's flying elephant Dumbo. At the moment scientists know that there are 37 different types of the Grimpoteuthis [1] each having a different aspect from all the others. These features could be larger ears or different colours. As these animals live at the bottom of the sea they have a very small food supply. Prey include Crustaceans, bivalves, worms on the ocean floor and Copepods.[2] These octopi have a short life span. The average life span of various Grimpoteuthis species is 3 to 5 years.

All species of Grimpoteuthis are bathyal creatures, living at extreme depths of 3,000 to 4,000 metres (9,800 to 13,100 ft) with some living up to 7,000 metres (23,000 ft) below sea level, which is the deepest of any known octopus.[3] They are some of the rarest of the Octopoda species. They have been found worldwide in the waters of New Zealand, Australia, Monterrey Bay, Oregon, Philippines, Martha's Vineyard, Papua New Guinea and Azores. They can flush the transparent layer of their skin at will, and are pelagic animals, as with all other cirrate octopuses. The largest Dumbo octopus ever recorded was 5.9 ft (1.8 m) in length and weighed 13 pounds (5.9 kg).[4] The average size for most species is 20–30 cm (7.9–12 in) length. The average weight is still undetermined.

Dorsal (left) and ventral (right) aspects of a mature female of G. innominata (73 mm ML)

Species[edit]

Several species formerly classified in this genus were moved to other opisthoteuthid genera.[5]

Appearance[edit]

As previously mentioned the most acknowledged physical feature of the Grimpoteuthis is the large ear like fins that resemble the Disney character Dumbo. Another noticeable feature about the Dumbo Octopus is the tentacles. When the Grimpoteuthis swims/spreads its tentacles out it forms a skirt like shape around the animals body. These Tentacles make the octopus classify as an Umbrella octopus. The Grimpoteuthis comes in a range of different colours. Some of these colours are red, orange, blue and in some cases purple. Between the animals eyes and lower down the Grimpoteuthis has an indent where beak sits. This beak is used for eating food and catching food. Certain breeds of Grimpoteuthis can have 'V' or 'U' shaped shields/shells. These shields/shells are used for protection against the threats the animal faces. The Grimpoteuthis is a very small animal compared to other animals in the sea. On average, species of Grimpoteuthis grow to about 20 centimetres in length (8 inches).[6] These animals have very large eyes. On average the eyes of these animals are 12mm wide.

Range and Habitat[edit]

Species of Grimpoteuthis are assumed to have a worldwide distribution. Specimens have been found off the coast of Oregon, The Philippines, Martha's Vineyard, Azores, New Zealand, Australia, California, Papua, and New Guinea. Dumbo octopuses are among the deepest living octopuses that have been observed. They can survive in extreme depths and have been found in the range of 400 meters to 4,800 meters which equates to 13,000 ft. Since they are living at extreme depths they are suited for living in colder temperatures. These species occupy a variety of depths and temperatures.

Threats[edit]

Various species of Grimpoteuthis face few direct man-made threats given as how the various species live on average below 9,800 feet.[7] Natural predators include sharks, killer whales, tuna and predatory cephalopods.

Behavior[edit]

The genus has a distinct habit of swimming. They flap their ear-like fins to propel themselves upwards. Movement of the tentacles can be used to help the animal move in any direction. The tentacles permit the animal to crawl along the seafloor, to capture prey, lay eggs, explore, etc. Dumbos hover above the sea floor, searching for polychaete worms, pelagic copepods, isopods, amphipods, and other crustaceans for food.[8] Prey is captured by pouncing on the target, which then swallowed whole.[9]

Breeding[edit]

Females have no distinct period for breeding. Females carrying multiple eggs in various stages of maturation, proving that there is no optimal breeding period. Male octopuses have a separate protuberance on one of their tentacles that carries an encapsulated sperm packet to the female. It is hypothesized that the female can then distribute this sperm to the eggs at any given time based on environmental conditions. The females lay the eggs under small rocks or on shells in the deep ocean or can even carry them on her tentacles, by tucking the eggs behind the wide webbing, until she finds a safe place that would provide them with the best fitness. As with other octopi, females do not invest any further time in the young after they hatch because once they are born they are big enough to defend themselves.

References[edit]

  1. ^ Young, Richard. http://tolweb.org/Grimpoteuthis. Retrieved 10 May 2014.  Missing or empty |title= (help)
  2. ^ "Finned Deep-sea Octopuses". Marinebio. Retrieved 8 May 2014. 
  3. ^ http://www.aquariumofpacific.org/onlinelearningcenter/species/dumbo_octopus
  4. ^ "NOAA Researchers, Ships Participate in Census of Marine Life’s Decade of Discovery" (Press release). National Oceanic and Atmospheric Administration. November 23, 2009. Retrieved May 11, 2011. 
  5. ^ Collins, Martin A. (2003). "The genus Grimpoteuthis (Octopoda: Grimpoteuthidae) in the north-east Atlantic, with descriptions of three new species". Zoological Journal of the Linnean Society 139: 93–127. doi:10.1046/j.1096-3642.2003.00074.x. 
  6. ^ "Facts About the Dumbo Octopus". Buzzle. Retrieved 8 May 2014. 
  7. ^ "Grimpoteuthis, The Dumbo Octopus". Ocean Portal. Retrieved 10 May 2014. 
  8. ^ Collins, M.A. & R. Villaneuva. (2006). Taxonomy, ecology and behaviour of the cirrate octopods. In: Gibson, R.N., R.J.A. Atkinson & J.D.M. Gordon (eds.) Oceanography and Marine Biology: An Annual Review, Volume 44. Taylor and Francis, London. pp. 277–322.
  9. ^ http://www.aquariumofpacific.org/onlinelearningcenter/species/dumbo_octopus

External links[edit]