Grimpoteuthis

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

14, see text

The octopuses of the genus Grimpoteuthis, also known as Dumbo octopuses or Dumbo octopods, are named for the ear-like fins protruding from the top of their head-like bodies, resembling the ears of Walt Disney's flying elephant Dumbo. 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 Dumbos 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".

They 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.[1] They are some of the rarest of the Octopoda species. They have been found worldwide in the waters of New Zealand and Australia, Monterey Bay, California, Oregon, Philippines and in Papua, New Guinea. 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 6 ft 32 in (1.8 m) in length and weighed 13 pounds (5.9 kg).[2] 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)

Dumbos hover above the sea floor, searching for polychaetes, pelagic copepods, isopods, amphipods, and other crustaceans for food.[3] The Dumbo octopus is strange in the way it consumes food. It pounces on its prey then swallows it whole which is a unique characteristic to the genus Grimpoteuthis.[4] Most of their food is found around ocean vent ecosystems or floating in the current. They can move in many different ways. Flapping their Dumbo ear-like fins gets them moving, but expanding and contracting the webbing between their arms or shooting water through their funnel causes a sudden thrust, needed to escape from predators. They can also simply use a more ordinary octopus way of traveling by crawling on their tentacles. Males and females differ in their size and sucker patterns. Dissected females have yielded eggs during different stages of development, which has led to the conclusion that females lay eggs constantly, with no distinct breeding season.[5] Females usually lay their eggs under small rocks or in shells in the deep ocean. Male Dumbo octopi possess an enlarged segment on one of their arms, similar to the hectocotylus arm of other cephalopods. This modified arm transfers masses of spermatophores into the female's mantle during copulation, as occurs in other cephalopods.[6] It is thought that females can utilize sperm for fertilization whenever they want.

Species[edit]

Several species formerly classified in this genus were moved to other opisthoteuthid genera.[7]

References[edit]

  1. ^ http://www.aquariumofpacific.org/onlinelearningcenter/species/dumbo_octopus
  2. ^ "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. 
  3. ^ 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.
  4. ^ http://www.aquariumofpacific.org/onlinelearningcenter/species/dumbo_octopus
  5. ^ "Dumbo Octopus Information : Fun & Interesting Facts". Brighthub.com. Retrieved 2011-02-17. [self-published source?]
  6. ^ "essay: dumbo octopus". Web.mac.com. 2008-11-20. Retrieved 2011-02-17. [self-published source?]
  7. ^ 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. 

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