Bigfin squid | |
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A bigfin squid filmed in 2001, possibly an adult Magnapinna sp. | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Cephalopoda |
Order: | Oegopsida |
Superfamily: | Chiroteuthoidea |
Family: | Magnapinnidae Vecchione & Young, 1998 |
Genus: | Magnapinna Vecchione & Young, 1998 [1] |
Type species | |
Magnapinna pacifica Vecchione & Young, 1998 | |
Species | |
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Bigfin squids are a group of rarely seen cephalopods with a distinctive morphology. They are placed in the genus Magnapinna and family Magnapinnidae. [2] Although the family was described only from larval, paralarval, and juvenile specimens, numerous video observations of much larger squid with similar morphology are assumed to be adult specimens of the same family. [3]
The arms and tentacles of the squid are both extremely long, estimated at 4 to 8 m (13 to 26 ft). These appendages are held perpendicular to the body, creating "elbows". How the squid feeds is yet to be discovered. [4]
Magnapinna is thought to be the deepest-occurring squid genus, with sightings as deep as 6,212 metres (20,381 ft) below the surface, making it the only squid known to inhabit the hadal zone. [5] [6]
Magnapinna is the sister group to Joubiniteuthis , another bizarre, little-known deep-sea squid with an unusual body plan and long arms. Both Magnapinna and Joubiniteuthis are monotypic genera within their own families, Magnapinnidae and Joubiniteuthidae respectively. They are also closely related to the "whip-lash squid" in the families Chiroteuthidae and Mastigoteuthidae. [7]
The first record of this family comes from a specimen ( Magnapinna talismani ) caught off the Azores on 10 August 1883. [8] Due to the damaged nature of the find, little information could be discerned, and it was classified as a mastigoteuthid, first as Chiroteuthopsis talismani [8] and later as Mastigoteuthis talismani. In 1956, a similar squid (Magnapinna sp. C) was caught in the South Atlantic, but little was thought of it at the time. The specimen was illustrated in Alister Hardy's The Open Sea (1956), where it was identified as Octopodoteuthis sicula. [9]
During the 1980s, two additional immature specimens were found in the Atlantic (Magnapinna sp. A), and three more were found in the Pacific ( Magnapinna pacifica ). Researchers Michael Vecchione and Richard Young were the chief investigators of the finds, and eventually linked them to the two previous specimens, erecting the family Magnapinnidae in 1998, with Magnapinna pacifica as the type species. [10] Of particular interest was the very large fin size, up to 90% of the mantle length, that was responsible for the animals' common name.
A single specimen of a fifth species, Magnapinna sp. B, was collected in 2006. Magnapinna sp. A was described as Magnapinna atlantica in 2006. [11]
The genus was described from two juveniles and paralarva, none of which had developed the characteristic long arm tips. However, they did all have large fins, and were therefore named "magna pinna", meaning "big fin". [12]
The presumed adult stage of Magnapinna is known only from video observations from submersibles and ROVs; no physical specimens have yet been collected, leaving their exact identity unknown. These individuals and the collected juvenile specimens share the very large fins and the vermiform arm tips with no suckers, but the iconic elongated arm tips are known only from observed individuals. Although it has not been directly confirmed whether these squid are the same as the Magnapinna known from specimens, it is largely accepted that they are members of Magnapinnidae. [3] [13]
Although observations had been made over a decade earlier, adult bigfin squid only became known to science in 2001, when marine biology student Heather Holston sent footage of what she described as a "21-foot-long squid" to teuthologist Michael Vecchione. The footage had been recorded from an ROV in the Gulf of Mexico in January 2000 at the request of Holston's boyfriend Eric Leveton, who planned on showing it to her. Leveton was a structural engineer aboard the oil-drilling ship Millennium Explorer, who had happened to look into the ROV operation shack when the squid was observed by operators. Although Vecchione initially surmised from Holston's description that the footage might be the first video of a live giant squid (Architeuthis dux), he realized that the video itself portrayed a completely different squid that had no known identity. [14] [15] [16] [17]
My reaction was to jump out of my chair and start yelling profanities, because I knew it was something really different.
— Michael Vecchione, on the first sighting of an adult bigfin squid [15]
Further discussions with other cephalopod researchers found no leads on the identity of the squid, and it was thus dubbed the "mystery squid" for a portion of time. Analysis by Vecchione et al of previous footage from submersibles found other video records of bigfin squid, the earliest from 1988. Around the same time, new high-quality footage of a bigfin squid was also recorded off Hawaii by the ROV Tiburon. In December 2001, Vecchione et al published a paper collating these observations; this was also the first paper to identify them as potential members of the Magnapinnidae, which had been named by Vecchione from the juvenile specimens a few years earlier. [18] [15] [19] Independent of Vecchione's publication, Guerra et al published a paper the following year analyzing some of the early bigfin squid footage, and also identified them as potential adult magnapinnids. [20]
The specimens in the videos looked very distinct from all previously known squids. Uniquely among cephalopods, the arms and tentacles were of the same length and looked identical (similar to extinct belemnites). The appendages were also held perpendicular to the body, creating the appearance of strange "elbows". Most remarkable was the length of the elastic tentacles, which has been estimated at up to 15–20 times the mantle length. This trait is caused by filament coiling of the tentacles, a trait that is rare among similar species. [21] Estimates based on video evidence put the total length of the largest specimens at 8 m (25 ft) or more, with some estimates up to 12 m (40 ft). [22] Viewing close-ups of the body and head, it is apparent that the fins are extremely large, being proportionately nearly as big as those of bigfin squid larvae. While they do appear similar to the larvae, no specimens or samples of the adults have been taken. While their exact identity is unknown, all of the discovered specimens can be observed to have a brown-orange color body, translucent fins, near-white tentacles, and dark eyes. [4] These species of squids are mainly identifiable by their long thin arms and specific colors. The squid also have a very unique brachial crown that sets them aside from the rest of other families that are known. [23]
Little is known about the feeding-behaviour of these squids. Scientists have speculated that the bigfin squid feeds by dragging their arms and tentacles along the seafloor and grabbing edible organisms from the floor. [24] Alternatively, they may simply use a trapping technique, waiting passively for prey such as zooplankton [12] to bump into their arms [24] (see Cephalopod intelligence). The diet of the bigfin squid is unknown. However, cephalopods are known to feed on crustaceans, jellyfish, and even other cephalopods. [25]
The first visual record of an adult bigfin squid was in September 1988. The crew of the submersible Nautile encountered a bigfin squid off the coast of northern Brazil, 10°42.91′N40°53.43′W / 10.71517°N 40.89050°W , at a depth of 4,735 metres (15,535 ft). In July 1992, the Nautile again encountered these creatures, observing two individuals during a dive off the coast of Ghana at 3°40′N2°30′W / 3.667°N 2.500°W , first at 3,010 metres (9,880 ft) depth, and then again at 2,950 metres (9,680 ft). Both were filmed and photographed. [20] In November 1998, the Japanese crewed submersible Shinkai 6500 filmed another bigfin squid in the Indian Ocean south of Mauritius, at 32°45′S57°13′E / 32.750°S 57.217°E and 2,340 metres (7,680 ft). [26]
Eric Leveton's video, which was later shared with Vecchione, was taken from the remotely operated underwater vehicle (ROV) of the oil-drilling ship Millennium Explorer in January 2000, at Mississippi Canyon in the Gulf of Mexico ( 28°37′N88°00′W / 28.617°N 88.000°W ) at 2,195 metres (7,201 ft), and allowed for a size estimate. By comparison with the visible parts of the ROV, the squid was estimated to measure 7 metres (23 ft) with arms fully extended. [20] The Nautile filmed another Indian Ocean specimen at 19°32′S65°52′E / 19.533°S 65.867°E and 2,576 metres (8,451 ft), in the area of Rodrigues Island, in May 2000. [20] In October 2000, the crewed submersible Alvin found another bigfin squid at 1,940 metres (6,360 ft) in Atwater Valley [ d ], Gulf of Mexico ( 27°34.714′N88°30.59′W / 27.578567°N 88.50983°W ).
These videos did not receive any media attention; most were brief and fairly blurry. In May 2001, approximately ten minutes of crisp footage of a bigfin squid were acquired by ROV Tiburon, causing a flurry of attention when released. [27] These were taken in the Pacific Ocean north of Oʻahu, Hawaii ( 21°54′N158°12′W / 21.900°N 158.200°W ), at 3,380 metres (11,090 ft). This video and the pre-2001 videos (which had not previously received much scientific attention) were documented by Vecchione et al in a paper that year, and some of the earlier footage was further analyzed by Guerra et al (2002). [18] [20]
On 11 November 2007, a bigfin squid was filmed off Perdido, a drilling-site owned by Shell Oil Company, located 200 statute miles or 320 km off Houston, Texas in the Gulf of Mexico. The ROV that filmed the squid had originally been sent to retrieve drilling equipment from the seabed, and encountered the squid floating near a well. After being circulated within the oil industry, the footage was shared with National Geographic News to have its identity determined, and was released to the public in 2008. This video received significant online attention in the years since its filming. [24] [28] [29]
Observations of bigfin squid were made in the Great Australian Bight during towed camera and remote operated vehicle surveys in 2015 and 2017 respectively. [4] In 2018, the first observations of a bigfin squid were made from the Southern Caribbean, off the coast of Colombia. [30]
In March 2021, during the expedition to document the wreck of the USS Johnston, the submersible DSV Limiting Factor recorded footage of a juvenile bigfin squid from the Philippine Trench at a depth of 6,212 metres (20,381 ft). This is the deepest observation of any squid, and rivalled only by some unidentified cirrate octopods from the same habitat as the deepest observation of any cephalopod. This makes Magnapinna the first squid known to inhabit the hadal zone. [5] [6]
On 9 November 2021, a video of a bigfin squid was captured at a ridge feature off the West Florida Escarpment by an ROV from the NOAAS Okeanos Explorer as part of the Windows to the Deep 2021 expedition. [31] [32] The squid was found at a depth of 2,385 m (7,825 ft), and its size is currently being measured using paired lasers. [33]
ROV SuBastian of Schmidt Ocean Institute observed a bigfin squid in close proximity to a black smoker-type hydrothermal vent on 4 April 2023, during the "In Search of Hydrothermal Lost Cities" expedition. The squid was seen at a depth of 1,931 m (6,335 ft). [34] [35] [36]
The giant squid is a species of deep-ocean dwelling squid in the family Architeuthidae. It can grow to a tremendous size, offering an example of abyssal gigantism: recent estimates put the maximum size at around 12–13 m (39–43 ft) for females and 10 m (33 ft) for males, from the posterior fins to the tip of the two long tentacles. This makes it longer than the colossal squid at an estimated 9–10 m (30–33 ft), but substantially lighter, as the tentacles make up most of the length. The mantle of the giant squid is about 2 m long, and the length of the squid excluding its tentacles rarely exceeds 5 m (16 ft). Claims of specimens measuring 20 m (66 ft) or more have not been scientifically documented.
Spirula spirula is a species of deep-water squid-like cephalopod mollusk. It is the only extant member of the genus Spirula, the family Spirulidae, and the order Spirulida. Because of the shape of its internal shell, it is commonly known as the ram's horn squid or the little post horn squid. Because the live animal has a light-emitting organ, it is also sometimes known as the tail-light squid.
The vampire squid is a small cephalopod found throughout temperate and tropical oceans in extreme deep sea conditions. The vampire squid uses its bioluminescent organs and its unique oxygen metabolism to thrive in the parts of the ocean with the lowest concentrations of oxygen. It has two long retractile filaments, located between the first two pairs of arms on its dorsal side, which distinguish it from both octopuses and squids, and places it in its own order, Vampyromorphida, although its closest relatives are octopods. As a phylogenetic relict, it is the only known surviving member of its order.
The Mastigoteuthidae, also known as whip-lash squid, are a family of small deep-sea squid. Approximately 20 known species in six genera are represented, with members found in both the mesopelagic and bathypelagic zone of most oceans. Originally described by Verill in 1881, it was later lowered by Chun (1920) to a subfamily (Mastigoteuthinae) of the Chiroteuthidae. However, Roper et al. (1969) raised it back to the family level, and this has not been changed since. The taxonomy of this family is extremely unstable, and there have been at times one genus, two genera and four subgenera(Salcedo-Vargas & Okutani, 1994), two genera and several 'groups', five genera and one species with an uncertain placement, or six genera.
The hadal zone, also known as the hadopelagic zone, is the deepest region of the ocean, lying within oceanic trenches. The hadal zone ranges from around 6 to 11 km below sea level, and exists in long, narrow, topographic V-shaped depressions.
Taningia danae, the Dana octopus squid, is a species of squid in the family Octopoteuthidae. It is one of the largest known squid species, reaching a mantle length of 1.7 m (5.6 ft) and total length of 2.3 m (7.5 ft). The largest known specimen, a mature female, weighed 161.4 kg (356 lb).[nb a]
A. aldrichi is a small species of squid found in northern Australian waters. The species was described by Chung Cheng Lu in 2005 based on specimens collected in the inshore waters of Northern Australia. The largest known individual of this species is a mature female measuring 27.6 mm (1.09 in) in mantle length (ML). The holotype is a mature male of 21.3 mm (0.84 in) ML. A live specimen of A. aldrichi has yet to be recorded.
Cephalopods, which include squids and octopuses, vary enormously in size. The smallest are only about 1 centimetre (0.39 in) long and weigh less than 1 gram (0.035 oz) at maturity, while the giant squid can exceed 10 metres (33 ft) in length and the colossal squid weighs close to half a tonne (1,100 lb), making them the largest living invertebrates. Living species range in mass more than three-billion-fold, or across nine orders of magnitude, from the lightest hatchlings to the heaviest adults. Certain cephalopod species are also noted for having individual body parts of exceptional size.
Magnapinna atlantica, previously known as "Magnapinna sp. A", is a species of bigfin squid known from only two specimens collected in the northern Atlantic Ocean. It is characterised by several unique morphological features: the tentacle bases are narrower than adjacent arm bases, the proximal tentacle lacks suckers but possesses glandular structures, and the animal's pigment is contained mostly in functional chromatophores.
Magnapinna pacifica is a species of bigfin squid known only from three immature specimens; two caught at a depth of less than 300 m (980 ft) and one from a fish stomach. M. pacifica is the type species of the genus Magnapinna. It is characterised primarily by its proximal tentacles, which are wider than adjacent arms and bear numerous suckers.
Magnapinna talismani is a species of bigfin squid known only from a single damaged specimen. It is characterised by small white nodules present on the ventral surface of its fins.
Magnapinna sp. B is an undescribed species of bigfin squid known only from a single immature specimen collected in the northern Atlantic Ocean.
Magnapinna sp. C is an undescribed species of bigfin squid known only from a single specimen of 79-millimetre (3.1 in) mantle length (ML) collected in the southern Atlantic Ocean and held in the Natural History Museum.
USNS Indomitable (T-AGOS-7) was a United States Navy Stalwart-class ocean surveillance ship in service from 1985 to 2002. From 2003 until 18 June 2014, she was in commission in the National Oceanic and Atmospheric Administration (NOAA) as the oceanographic research ship NOAAS McArthur II. As of 2018 it serves as a mother ship now named the Deep Submersible Support Vessel (DSSV) Pressure Drop for the crewed deep-ocean research submersible DSV Limiting Factor.
Sepioteuthis lessoniana, commonly known as the bigfin reef squid, tiger squid, glitter squid, oval squid, or northern calamari, is a species of loliginid squid. It is one of the three currently recognized species belonging to the genus Sepioteuthis. Studies in 1993, however, have indicated that bigfin reef squids may comprise a cryptic species complex. The species is likely to include several very similar and closely related species.
Teuthowenia megalops, sometimes known as the Atlantic cranch squid, is a species of glass squid from the subarctic and temperate waters of the northern Atlantic Ocean. They are moderately sized squid with a maximum mantle length of 40 cm (16 in). Their very large eyes are the source for the specific name megalops. Like other members of the genus Teuthowenia, they are easily recognizable by the presence of three bioluminescent organs (photophores) on their eyeballs.
Cephalopod fins, sometimes known as wings, are paired flap-like locomotory appendages. They are found in ten-limbed cephalopods as well as in the eight-limbed cirrate octopuses and vampire squid. Many extinct cephalopod groups also possessed fins. Nautiluses and the more familiar incirrate octopuses lack swimming fins. An extreme development of the cephalopod fin is seen in the bigfin squid of the family Magnapinnidae.
Richard E. Young is a teuthologist. He is an Emeritus Professor of Oceanography at the University of Hawaii's School of Ocean and Earth Science and Technology.
Alan John Jamieson is a Scottish marine biologist, engineer, explorer and author, best known for his deep-sea exploration and study of life at the deepest places in the oceans. He is known for extensive use of deep-sea landers to establish the maximum depth and community dynamics of many organismal groups, as well as the discovery of many new species and highlighting the presence of anthropogenic impacts at full ocean depth. During the Five Deeps Expedition, and follow on expeditions in 2020, he completed various dives in a manned submersible to some of the deepest places in the world. He has published over 100 scientific papers and participated in 65 deep-sea expeditions.
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