24-399: Opisthoteuthidae Grimpoteuthidae Cirroteuthidae Stauroteuthidae Cirroctopodidae Cirrina or Cirrata is a suborder and one of the two main divisions of octopuses . Cirrate octopuses have a small, internal shell and two fins on their head, while their sister suborder Incirrina has neither. The fins of cirrate octopods are associated with a unique cartilage-like shell in
48-532: A group of pelagic octopuses . Umbrella octopuses are characterized by a web of skin between the arms , causing them to somewhat resemble an opened umbrella when the arms are spread. Opisthoteuthidae are a group of octopuses characterized by a web of skin in between their arms. They broad U-shaped shell that support muscles for a pair of small fins on the mantle, these fins are far less developed than other families in Cirrina and essentially only act as stabilizers when
72-474: A shell sac. In cross-section, the fins have distinct proximal and distal regions, both of which are covered by a thin surface sheath of muscle. The suborder is named for small, cilia -like strands (cirri) on the arms of the octopus, a pair for each sucker. These are thought to play some role in feeding, perhaps by creating currents of water that help bring food closer to the beak. Cirrate octopuses are noteworthy for lacking ink sacs. The oldest known member of
96-468: A single family (Stauroteuthidae being synonymized under Cirroteuthidae), but more recent analysis using nuclear genes does show separation. The family Grimpoteuthidae has also at times been synonymized under Opisthoteuthidae but is currently well supported. This article related to the octopus is a stub . You can help Misplaced Pages by expanding it . Opisthoteuthidae Opisthoteuthis Umbrella octopuses ( family Opisthoteuthidae ) are
120-632: A time, with no seasonality in spawning (however, most of these aspects of reproductive biology have only been confirmed in Opisthoteuthis , not Grimpoteuthis ). Mating in cirrate octopuses has never been observed, and unlike other octopuses, members of Cirrata lack a hectocotylus for the transfer of sperm packets. Cirrate octopus eggs are large and have a tough casing surrounding the chorion (not found in other octopuses), and Grimpoteuthis in particular attach their eggs to deep sea corals ( octocorals ). The female cirrate octopus does not guard or incubate
144-541: Is similar to Opisthoteuthis that trap small prey items in the webbing (either by enclosing the prey in the arm webbing or between the webbing and the seafloor) and then use the cirri (fingerlike projections along the arms) to move food to the mouth. Known prey items (from dissected animals) include benthic polychaetes , benthopelagic copepods , amphipods and isopods . The cirrate octopuses are classified as 'continuous spawners': Females carry multiple eggs in various stages of maturation, and only lay one or two eggs at
168-899: Is sister to the clade that contains those other groups. However, subsequent studies, using a greater coverage of species and genes, have found Cirrata and Incirrata to be monophyletic clades, consistent with earlier morphological and molecular studies. The family level clades recognized within Cirrina has changed over time. Currently five families are recognized by the World Register of Marine Species allocated to two superfamily level clades, Superfamily Cirroteuthoidea ( Cirroteuthidae , Stauroteuthidae ) and Superfamily Opisthoteuthoidea ( Opisthoteuthidae , Grimpoteuthidae , and Cirroctopodidae ), with these groups also recognized in recent molecular work. The families Cirroteuthidae and Stauroteuthidae have been problematic, while they are distinct morphologically, molecular studies using mitochondrial genes revealed
192-405: Is web-inversion which is when they have their arms turned upwards and their web with the oral surface facing outwards. The oral surface can be facing the floor, or the octopuses may lie laterally so their side is in contact with the floor. It has been noted that these defensive behaviors are the positions the octopuses may go into while feeding as well, but it is possible that this could be because of
216-586: The Azores , New Zealand , Australia , California , Papua and New Guinea , and in the Gulf of Mexico . A fairly recent observation was on 21 June 2022 at 1,250 metres (4,100 ft) by the vessel Normand Ocean , which inspects drilling platforms with underwater drones; the vessel was examining chains and risers on the Aasta Hansteen platform outside Trøndelag , Norway . The most recent observation as of 2023
240-464: The South China Sea. They stay within 3,000-4,000 meters below sea level and try to stay hovering over the ocean floor. Family Opisthoteuthidae has classically contained a single genus, Opisthoteuthis , which has recently been split into three genera on the basis of differences in enlarged suckers on male specimens. Genera Grimpoteuthis , Luteuthis , and Cryptoteuthis now are included in
264-503: The animal swims (using a medusoid motion of the arms and webbing). This structure makes the umbrella octopus resemble an umbrella when they spread their arms/web out. The structure of the umbrella octopus has the oral surface below the mantle of the octopuses and the web with their arms surround the bottom of the mantle. Their outer skin has a very delicate consistency that results in white spots appearing on their skin when damaged. Although Opisthoteuthidae are categorized as cirrates, unlike
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#1732854906056288-580: The bottom to maintain balance. When flat-spreading they spread their arms and web, so it is parallel to the bottom and they keep the edges of their arms curved inwards. Their heads will point backwards at a small angle and their fins will be used for stabilization. Opisthoteuthidae are deep sea creatures that have been found in the Clipperton-Clarion Fracture Zone in the Pacific Ocean at a depth of about 4,800 m. They have also been found in
312-470: The eggs (again unlike other octopuses). Grimpoteuthis hatchlings emerge as "fully competent" juveniles with all of the sensory and motor features to survive on their own. Sexual dimorphism between males and females is less noticeable and consistent in Grimpoteuthis compared to other cirrate octopuses (such as Opisthoteuthis ). In some species (e.g., G. bathynectes and G.. discoveryi ),
336-423: The family Grimpoteuthidae . Grimpoteuthis 17, see text Enigmatiteuthis Grimpoteuthis is a genus of pelagic cirrate (finned) octopods known as the dumbo octopuses . The name "dumbo" originates from their resemblance to the title character of Disney 's 1941 film Dumbo , having two prominent ear-like fins which extend from the mantle above each eye. There are 17 species recognized in
360-476: The genus. Prey include crustaceans , bivalves , worms and copepods . The average life span of various Grimpoteuthis species is 3 to 5 years. Species of Grimpoteuthis are assumed to have a worldwide distribution, living in the cold, abyssal depths ranging from 1,000–7,000 metres (3,300–23,000 ft). Specimens have been found off the coasts of Oregon , the Philippines , Martha's Vineyard ,
384-542: The group is Paleocirroteuthis from the Late Cretaceous of Japan and Canada. A molecular phylogeny based on mitochondrial and nuclear DNA marker sequences by Sanchez et al. , 2018, shows that the Cirrina is paraphyletic , i.e. it is not a single clade . Instead, a clade containing Opisthoteuthidae and Cirroctopodidae is sister to the Octopodida, while a clade containing Cirroteuthidae and Stauroteuthidae
408-488: The males have enlarged suckers relative to the females, but no such enlargement is found in other Grimpoteuthis species. Species of Grimpoteuthis face few direct threats from humans, living at depths of 1,000 meters (3,300 ft) and below. Natural predators of cirrate octopuses include large teleost fish and sharks, and even marine mammals such as sperm whales and seals, but these are mostly predators of other cirrate genera, and Grimpoteuthis has only been recorded in
432-516: The mantle fins for rapid locomotion. The cushiony cartilage that can be found in the proximal position of the fin of the octopus is responsible for acting as a support for the thick muscles that are attached, these muscles are what allow for rapid locomotion. Although it has been suggested that species of Grimpoteuthis are capable of jet-propulsion (while swimming using the fins), this has since been deemed unlikely. Feeding behavior has not been directly observed in Grimpoteuthis , but presumably
456-401: The other cirrates, they do not have an intermediate web; rather, they use the web in between their arms to mimic the intermediate web that other cirrates have. Lacking an intermediate web is what causes the indentations in the outer edge of their arms that make them look like an umbrella. Opisthoteuthidae lack an intermediate web but they mimic the defensive mechanism of ballooning by extending
480-864: The specimen may have been captured while the net was descending to this depth). However, in 2020, Grimpoteuthis was spotted 6,957 metres (22,825 ft) deep in the Java Trench , confirming the hadal distribution of this genus. As noted below, many species collected on the Challenger expedition were initially classified in the genera Cirroteuthis and Stauroteuthis . Several species formerly classified as Grimpoteuthis were moved to genera Cirroctopus and Opisthoteuthis . A new family, Grimpoteuthididae (alternatively spelled Grimpoteuthidae ), has been proposed to accommodate Grimpoteuthis and those of genera Enigmatiteuthis , Cryptoteuthis , and Luteuthis . The persistent confusion and disparity about
504-417: The stress of being captured and placed in an aquarium to be observed. When resting at the floor, the octopus's behavior falls into one of two tactics: bottom-resting or flat-spreading. Bottom-resting is when the octopus is resting near the floor. It will erect its mantle, curve the outer edges of its arms inwards to have them be the only part making contact with the floor. The fins are extended out parallel to
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#1732854906056528-490: The taxonomy of these species has been attributed to the poor quality and limited number of specimens available for study. Observations of animals in the Atlantic reveal that Grimpoteuthis often rest on the seafloor with the arms and web spread out and uses its arms to slowly crawl along the seafloor. When disturbed the webbing and arms are contracted to push the animal off the seafloor with it then transitioning to movement using
552-420: The web between their arms as much as possible and curving the outer edges of their arms inwards in order to have the edges touch the ground. They also extend their fins parallel to the floor to help keep their balance or they curve them around their mantle. Opisthoteuthidae have been observed to hold this position for five and a half minutes. Another defensive mechanism that Opisthoteuthidae have been observed using
576-463: Was on 24 May 2023 at 2 108 meters, this time in Guyana by the vessel Far Samson , which also uses underwater drones. Dumbo octopuses are the deepest living octopuses known, with some specimens captured or observed at hadal depths. One Grimpoteuthis specimen was captured 60 kilometres (37 mi) southeast of Grand Cayman at 7,279 metres (23,881 ft), but this depth is uncertain (as
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