Grimpoteuthis
{{short description|Genus of cephalopods known as the dumbo octopuses}}
{{use dmy dates|date=September 2024}}
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{{Automatic taxobox
| image = Dumbo-hires (cropped).jpg
| taxon = Grimpoteuthis
| authority = Robson, 1932
| type_species = Grimpoteuthis discoveryi
| type_species_authority = Collins, (2003)
| subdivision_ranks = Species
| subdivision = 17, see text
| synonyms = Enigmatiteuthis
| synonyms_ref = O'Shea (1999)
}}
{{Cite journal |last1=Voss |first1=Gilbert L. |last2=Pearcy |first2=William G. |date=17 October 1990 |title=Deep-water octopods (Mollusca: Cephalopoda) of the northeastern Pacific |url=https://www.biodiversitylibrary.org/item/53708 |journal=Proceedings of the California Academy of Sciences |series=4th series |publisher=California Academy of Sciences |publication-date=1990–1992 |volume=47 |pages=47–94 |via=biodiversitylibrary.org |number=3 |place=San Francisco, CA}}
is a genus of pelagic cirrate (finned) octopods known as the dumbo octopus. 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 the genus.
{{Cite web |year=2022 |title=Grimpoteuthis {{small|(Robson, 1932)}} |url=https://www.marinespecies.org/aphia.php?p=taxdetails&id=138293 |website=World Register of Marine Species (WoRMS) |via=marinespecies.org}}{{Cite web |last=Young |first=Richard |title=Grimpoteuthis |url=http://tolweb.org/Grimpoteuthis |access-date=10 May 2014 |website=Tree of Life Web Project (tolweb.org)}}
The Dumbo octopus has a gelatinous body and uses fin propulsion for movement, which also helps it to conserve energy in its extreme deep-sea environment. These unique physical traits distinguish it from other octopuses, which primarily rely on jet propulsion.
Prey include crustaceans, bivalves, worms and copepods.{{Cite web |title=Finned deep-sea octopuses |url=http://marinebio.org/species.asp?id=558 |access-date=8 May 2014 |website=MarineBio.org}} The average life span of various Grimpoteuthis species is 3 to 5 years.{{Cite web |last=Roberts |first=Emily |date=October 8, 2018 |title=A Deep Dive with the Dumbo Octopus - Ocean Conservancy |url=https://oceanconservancy.org/blog/2018/10/08/everything-need-know-dumbo-octopus/#:~:text=The%20average%20life%20expectancy%20of%20the%20dumbo%20octopus%20is%20three%20to%20five%20years. |access-date=November 8, 2024}}{{Cite web |last=Fazal |first=Rehman |date=29 September 2024 |title=A Deep Dive with the Dumbo Octopus,All About Dumbo Octopus |url=https://oceanfauna.net/dumbo-octopus/ |access-date=29 September 2024 |website=Ocean Fauna}}{{dead link|date=November 2024}}
Range and habitat
File:Grimpoteuthis 2108m.jpg.]]
Species of Grimpoteuthis are assumed to have a worldwide distribution, living in the cold, abyssal depths ranging from {{convert|1000|-|7000|m}}. Specimens have been found off the coasts of Oregon, the Philippines, Martha's Vineyard, 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 {{convert|1250|m}} 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. Another recent observation {{as of|2023|lc=y}} was on 24 May 2023 at {{gaps|2|108|meters,}} this time in Guyana by the vessel Far Samson, which also uses underwater drones.
Further to this, the most recent known recorded observation was on 5th March 2025 by the Vessel "Boka Falcon" with a Workclass Remotely Operated Vehicle working at a depth of 960m in the Gulf Of Guinea approximately 65km South West of Abidjan, Ivory Coast. Two separate sightings approximate 20 minutes apart were observed.
Dumbo octopuses are the deepest living octopuses known, with some specimens captured or observed at hadal depths. One Grimpoteuthis specimen was captured {{convert|60|km}} southeast of Grand Cayman at {{convert|7279|m}}, but this depth is uncertain (as the specimen may have been captured while the net was descending to this depth).{{Cite book |last1=Brunt |first1=M. A. |title=The Cayman Islands: Natural history and biogeography |last2=Davies |first2=J. E. |publisher=Kluwer Academic |year=1994 |isbn=0-7923-2462-5 |location=Dordrecht, NL |page=175}}
In 2020, Grimpoteuthis was spotted {{convert|6957|m}} deep in the Java Trench, confirming the hadal distribution of this genus.{{Cite journal |last1=Jamieson |first1=Alan J. |last2=Vecchione |first2=Michael |date=26 May 2020 |title=First in situ observation of Cephalopoda at hadal depths (Octopoda: Opisthoteuthidae: Grimpoteuthis sp.) |journal=Marine Biology |volume=167 |issue=6 |at=article 82 |doi=10.1007/s00227-020-03701-1 |doi-access=free|bibcode=2020MarBi.167...82J }}
Species and taxonomy
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 later 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.{{Cite journal |last1=Piertney |first1=Stuart B. |last2=Hudelot |first2=Cendrine |last3=Hochberg |first3=F.G. |last4=Collins |first4=Martin A. |year=2003 |title=Phylogenetic relationships among cirrate octopods (Mollusca: Cephalopoda) resolved using mitochondrial 16S ribosomal DNA sequences |journal=Molecular Phylogenetics and Evolution |volume=27 |issue=2 |pages=348–353 |doi=10.1016/S1055-7903(02)00420-7 |pmid=12695097|bibcode=2003MolPE..27..348P }} The persistent confusion and disparity about the taxonomy of these species has been attributed to the poor quality and limited number of specimens available for study.
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Movement, characteristics, and food supply
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 propel the animal off the seafloor and using the mantle fins for rapid locomotion.{{Cite journal |last1=Villanueva |first1=R. |last2=Segonzac |first2=M. |last3=Guerra |first3=A. |date=July 1997 |title=Locomotion modes of deep-sea cirrate octopods (Cephalopoda) based on observations from video recordings on the Mid-Atlantic Ridge |journal=Marine Biology |volume=129 |issue=1 |pages=113–122 |doi=10.1007/s002270050152 |bibcode=1997MarBi.129..113V |s2cid=85848021}}
The cushiony cartilage that can be found in the proximal position of the fin of Grimpoteuthis is responsible for acting as a support for the thick muscles that 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 is similar to Opisthoteuthis which can 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.
Breeding
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 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).{{Cite journal |last1=Ziegler |first1=Alexander |last2=Miller |first2=Abigail |last3=Nagelmann |first3=Nina |year=2021 |title=Novel insights into early life stages of finned octopods (Octopoda: Cirrata) |journal=Swiss Journal of Palaeontology |volume=140 |issue=1 |page=24 |doi=10.1186/s13358-021-00240-0 |s2cid=245330726 |doi-access=free|bibcode=2021SwJP..140...24Z }}
Unlike other octopuses, the female cirrate octopus does not guard or incubate the eggs.
Grimpoteuthis hatchlings emerge as "fully competent" juveniles with all of the sensory and motor features to survive on their own.{{Cite journal |last1=Shea |first1=Elizabeth K. |last2=Ziegler |first2=Alexander |last3=Faber |first3=Cornelius |last4=Shank |first4=Timothy M. |date=February 2018 |title=Dumbo octopod hatchling provides insight into early cirrate life cycle |journal=Current Biology |volume=28 |issue=4 |pages=R144–R145 |doi=10.1016/j.cub.2018.01.032 |pmid=29462576 |doi-access=free|bibcode=2018CBio...28.R144S }}
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), the males have enlarged suckers relative to the females, but no such enlargement is found in other Grimpoteuthis species.
Threats
Species of Grimpoteuthis face few direct threats from humans largely due to living at depths of {{Convert|1000|meters|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. Grimpoteuthis has only been recorded in the stomach contents of a shark.{{Cite book |last1=Collins |first1=Martin A. |last2=Villanueva |first2=Roger |year=2006 |title=Taxonomy, ecology and behaviour of the cirrate octopods |journal=Oceanography and Marine Biology |series=Annual Review |volume=44 |pages=277–322 |doi=10.1201/9781420006391.ch6 |doi-broken-date=12 July 2025 |isbn=978-0-8493-7044-1}}
The Grimpoteuthis do not have an ink sac (as is the case with all cirrate octopuses). Furthermore, the cirrate octopuses lack innervated chromatophores and therefore are not capable of changing color (despite some unreferenced statements to the contrary).{{Cite journal |last=Hadjisolomou |first=Stavros P. |date=March 2017 |title=SpotMetrics: An open-source image-analysis software plugin for automatic chromatophore detection and measurement |journal=Frontiers in Physiology |volume=8 |pages=106 |doi=10.3389/fphys.2017.00106 |pmc=5331055 |pmid=28298896 |doi-access=free}}
How cirrate octopuses escape or avoid predators is largely unknown.
References
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External links
{{commonscat|Grimpoteuthis}}
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- {{Cite AV media |url=https://www.bbc.co.uk/nature/life/Grimpoteuthis#p00hn4zc |title=Dumbo octopus |type=video |publisher=BBC Nature |website=bbc.co.uk}}
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Category:Cephalopods of Oceania