Overview

Brief Summary

Introduction

The family Magnapinnidae was originally based on a single species, Magnapinna pacifica. However, the discovery of a second species, M. atlantica, and the realization that other known specimens and species belong in the family indicate that this poorly known deep-sea family may have as many as five species based on only eleven specimens. However, as only three of the species are well-described, and four of them are weakly separated from one another, we cannot infer yet that this is a highly speciose family.

Vecchione et al. (2002) described the occurrence of a strange, large squid recorded only by submersible or ROV observations (see title photograph). The authors suggested that these squid belong in the family Magnapinnidae. With the discovery of more species, although based only on small individuals, we are now confident that these large deep-sea squid are magnapinnids, and we include them here. The title photograph shows the thicker regions of the arms and tentacles that are often held at nearly right angles to the body axis and the long, slender portions of the arms and tentacles that trail the squid and are nearly parallel to the body axis. Apparent counterparts for these regions of the arms/tentacles are present in the juveniles. For ease of description we give separate names to these two regions: the proximal-arms/tentacles and the distal-arms/tentacles.

Based on similarity (cladistic analyses have not been made), this family apparently belongs with the "chiroteuthid families" (Vecchione and Young, 1998). These families include the Chiroteuthidae, Mastigoteuthidae, Joubiniteuthidae, Batoteuthidae and Promachoteuthidae. It shares the following characteristics with these families:

  • Buccal connectives attach to ventral margins of arms IV.
  • Gladius apparently with elongate secondary conus (except in Promachoteuthidae).
  • Absence of the "teuthoid" tentacular club.

A few additional characters are shared with the Chiroteuthidae and Mastigoteuthidae:

  • Fins terminal (often large) extending well beyond the posterior end of the muscular mantle (this feature is also present in the Lepidoteuthidae).
  • Oval funnel-locking cartilage but without protrusions (this feature is also present in the Joubiniteuthidae and Promachoteuthidae).

Brief diagnosis:

One of the chiroteuthid families with ...

  • narrow, very elongate (vermiform) distal-arms and distal-tentacles.
  • very large fins.
  • an oval funnel locking-apparatus

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Comprehensive Description

Nomenclature

A list of all nominal genera and species in the Magnapinnidae can be found here. The list includes the status and type species of all genera, and the status, type repository and type locality of all species and all pertinent references.

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Characteristics

  1. Arms
    1. Arms with two regions: short, proximal-arms with large suckers and long, very slender distal-arms covered with minute suckers.
    2. Arms suckers with bi- to quadra-serial suckers on proximal-arms, multiple irregular series on distal arms.
    3. Figure. Ventral and dorsal views of the brachial crowns of M. pacifica, 51 mm ML . Drawing from Vecchione and Young (1998).

  2. Tentacles
    1. Tentacles with two regions: short, proximal-tentacles that may or may not bear numerous suckers and long, very slender distal-tentacles covered with numerous minute suckers.
    2. Tentacles without keels, terminal pads or locking apparatuses.

  3. Buccal crown
    1. Buccal connectives attach to ventral margins of arms IV.

  4. Head
    1. Eyes large.
    2. Head short without distinct neck or brachial pillar.

  5. Funnel
    1. Funnel with oval locking-apparatus without tragus or antitragus.

  6. Fins
    1. Fins terminal.
    2. Fins large, ca. 70-90% of ML.
    3. Muscular mantle restricted to the anterior 10-15% of the sessile region (ie, attached region of fins that doesn't include the free anterior fin lobes) of the fins.
    4. Short tail usually present. May represent drawn-out tip of fins that have been damaged.
    5. Figure. Ventral view of Magnapinna pacifica, holotype. Note that the muscular mantle terminates in the anterior region of the fins. Photograph from Vecchione and Young (1998), modified.

  7. Photophores
    1. Photophores absent.

Comments

Most described specimens are based on paralarvae or juveniles. The adult/subadult squid, observed from submersibles or ROVs, have the following features: The arms and tentacles typically are held in an unusual position: They extend at sharp angles to the body axis then abruptly (sometimes at a 90° angle) turn anteriorly. The "elbow" is, roughly, two thirds of the length of the mantle away from the body axis. This arm posture recalls the way in which the tentacles of Mastigoteuthis spp. are held apart although with the aid of the ventral arms. Rough estimates from videos indicate total lengths up to 7 m (Vecchione, et al, 2001). Arms and tentacles are approximately equal in thickness and length. The tentacles are usually not easily recognizable in videos; the arms and tentacles, therefore, appear as 10 equal appendages. Length of the arms/tentacles of the squid pictured below are about 10 times the ML although they are highly contractile. Guerra et al (2002) estimated that an individual they observed had arms/tentacles about 15-20 times the ML. The relative length of the arms/tentacles is far greater than in any other squid. The head appears to be small. Fin Length of the specimen pictured below is about 80% of the ML. Guerra et al (2002) estimated the fin length of their specimen at about two thirds of the ML. The fin position is terminal.

Figure. In-situ images of Magnapinna sp., Gulf of Mexico. Left - Side view showing long appendages. Right - Dorsal view showing common posture with proximal-arms/tentacles at nearly right angles to the body axis. Video frames of taken by DSV Alvin, Woods Hole Oceanographic Institution. Dives co-sponsored by NOAA Undersea Research Program, Minerals Management Service and National Energy Technology Lab.

Tentacle base much wider than arm IV base Proximal-tentacle with numerous suckers Proximal-tentacle with glandular structures. Chromatophores abundant
Habitat
M. pacifica Yes Yes No Yes North Pacific, North Atlantic
M. atlantica No No Yes Yes North Atlantic
Magnapinna sp. B No ? ? No North Atlantic
Magnapinna sp. C No No ? Yes South Atlantic
M. talismani No No ? Yes North Atlantic

Due to the poor condition of the single specimens of Magnapinna spp. B and C and M. talismani, our present understanding of the species in the family may be flawed. M. atlantica, M. talismani and Magnapinna sp. C could belong to the same species. The feature that most clearly separates M. atlantica is the presence of glandular structures on the proximal-tentacles. The recent discovery that these structures become relatively smaller with size and are easily lost due to damage indicates that these structures may have been lost in M. talismani and Magnapinna spp. B and Magnapinna sp. B, however, appears to differ from the others in the longer free-of-the-fin mantle and the broader orifices of the proximal-arm suckers.

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Ecology

Habitat

Depth range based on 1 specimen in 4 taxa.
Water temperature and chemistry ranges based on 1 sample.

Environmental ranges
  Depth range (m): 200 - 200
  Temperature range (°C): 8.460 - 8.460
  Nitrate (umol/L): 27.752 - 27.752
  Salinity (PPS): 34.013 - 34.013
  Oxygen (ml/l): 2.538 - 2.538
  Phosphate (umol/l): 2.096 - 2.096
  Silicate (umol/l): 36.058 - 36.058
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

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Molecular Biology and Genetics

Molecular Biology

Barcode data: Magnapinna sp. ARL-2008

The following is a representative barcode sequence, the centroid of all available sequences for this species.


There is 1 barcode sequence available from BOLD and GenBank.

Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.

See the BOLD taxonomy browser for more complete information about this specimen.

Other sequences that do not yet meet barcode criteria may also be available.

ACACTATATTTTATTTTTGGTATCTGAGCAGGACTCTTAGGAACCTCCCTA---AGACTAATAATTCGTACTGAACTGGGACAACCTGGCTCTCTACTTAATGAT---GATCAACTCTACAATGTGGTAGTTACCGCCCATGGATTTATTATAATTTTCTTTTTAGTTATACCCATTATAATTGGAGGGTTTGGAAATTGATTAGTACCTCTAATA---TTAGGAGCACCAGATATAGCATTCCCACGAATAAATAATATAAGATTTTGACTACTACCCCCGTCTTTAACCCTACTATTAGCCTCCTCAGCTGTAGAAAGAGGAGCTGGGACAGGATGGACAGTTTATCCTCCTTTATCTAGAAATATTTCTCATGCAGGACCTTCTGTAGATTTA---GCTATTTTTTCTCTTCATTTAGCAGGTGTATCCTCTATTTTAGGAGCAATTAATTTTATCACCACAATCTTAAATATACGATGGGAAGGATTACAAATAGAACGACTTCCTCTATTTGTATGATCTGTATTTATTACCGCAATTTTRCTACTTTTATCTTTACCGGTTTTAGCAGGG---GCCATCACCATGCTTTTAACAGACCGAAATTTTAATACTACTTTTTTTGATCCTAGAGGGGGAGGTGACCCAATCTTATATCAACATTTA
-- end --

Download FASTA File

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Statistics of barcoding coverage: Magnapinna sp. ARL-2008

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1
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Statistics of barcoding coverage

Barcode of Life Data Systems (BOLD) Stats
Specimen Records: 2
Specimens with Sequences: 1
Specimens with Barcodes: 1
Species: 2
Species With Barcodes: 1
Public Records: 1
Public Species: 1
Public BINs: 1
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Barcode data

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Wikipedia

Bigfin squid

The bigfin squids are a group of rarely seen cephalopods with a distinctive morphology. They are placed in the genus Magnapinna and family Magnapinnidae. Although the family is known only from larval, paralarval, and juvenile specimens, some authorities believe the adult creature has also been seen; several videos have been taken of animals nicknamed the "long-arm squid", which appear to have a similar morphology. Since none of the adult specimens have ever been captured or sampled, it remains uncertain if they are the same genus, or only distant relatives.

Physical specimens[edit]

The first record of this family comes from a specimen (Magnapinna talismani) caught off the Azores in 1907.[1] However, due to the damaged nature of the find, very little information could be discerned and it was classified as a mastigoteuthid, first as Chiroteuthopsis talismani[1] 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 Octopodoteuthopsis.[2]

During the 1990s, two more 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 up to the two previous specimens, erecting the family Magnapinnidae in 1998, with Magnapinna pacifica as the type species.[3] 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 2004. Magnapinna sp. A was described as Magnapinna atlantica in 2006.[4]

Sightings[edit]

The first visual record of the long-arm squid dates back to September 1988. The crew of the submersible Nautile encountered a long-armed squid off the coast of northern Brazil, 10°42.91′N 40°53.43′W / 10.71517°N 40.89050°W / 10.71517; -40.89050 (Bigfin squid (first sighting 1988)), at a depth of 4,735 metres (15,535 ft). In July 1992, the Nautile again came across these creatures, first observing one individual two times during a dive off the coast of Ghana at 3°40′N 2°30′W / 3.667°N 2.500°W / 3.667; -2.500 (Bigfin squid (sighting 1992)) and 3,010 metres (9,880 ft) depth, and then another one off Senegal at 2,950 metres (9,680 ft)[verification needed]. Both were filmed and photographed.[5] In November 1998, the Japanese manned submersible Shinkai 6500 filmed another long-armed squid in the Indian Ocean south of Mauritius, at 32°45′S 57°13′E / 32.750°S 57.217°E / -32.750; 57.217 (Bigfin squid (sighting 1998)) and 2,340 metres (7,680 ft).

The long-armed squid observed north of Hawai'i in 2001, showing the extremely large fins of this specimen

A third video taken from the ROV of the oil-drilling ship Millennium Explorer in January 2000, at Mississippi Canyon in the Gulf of Mexico (28°37′N 88°00′W / 28.617°N 88.000°W / 28.617; -88.000 (Bigfin squid (sighting 2000, Millennium Explorer))) at 2,195 metres (7,201 ft) allowed 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.[5] The ROV Atalante filmed another Indian Ocean specimen at 19°32′S 65°52′E / 19.533°S 65.867°E / -19.533; 65.867 (Bigfin squid (sighting 2000, Atalante)) and 2,576 metres (8,451 ft), in the area of Rodrigues Island, in May 2000.[5] The year 2000 was a boon year for observations of these enigmatic animals, for in October, the manned submersible Alvin found yet another long-armed squid at 1,940 metres (6,360 ft) in Atwater Valley, Gulf of Mexico (27°34.714′N 88°30.59′W / 27.578567°N 88.50983°W / 27.578567; -88.50983 (Bigfin squid (sighting 2000, Alvin))).

These videos did not receive any media attention; in any case, most were brief and fairly blurry. However, in May 2001, some ten minutes of crisp footage of a long-armed squid were acquired by ROV Tiburon, causing a flurry of attention when they were released.[6] These were taken in the Pacific Ocean north of Oʻahu, Hawaiʻi (21°54′N 158°12′W / 21.900°N 158.200°W / 21.900; -158.200 (Bigfin squid (sighting 2001))), at 3,380 metres (11,090 ft).

On November 11, 2007, a new video of a long-arm squid was filmed off Perdido, a drilling site owned by Shell Oil Company, located 200 statute miles (320 km) off Houston, Texas in the Gulf of Mexico.[7]

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 (like 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 stretching up to 15–20 times the mantle length. Estimates based on video evidence put the total length of the largest specimens at 8 metres (26 ft) or more.[8] On close ups of the body and head, it is also 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, leaving their exact identity unknown.

Feeding behavior[edit]

Very little is known about the feeding behavior of these squid. Scientists have speculated that bigfin squid feed by dragging their arms and tentacles along the seafloor, and grabbing edible organisms off the floor.[7] Alternatively, they may simply use a trapping technique, waiting passively for prey to bump into their arms.[7] (See Cephalopod intelligence.)

See also[edit]

References[edit]

  1. ^ a b Fischer, H. & L. Joubin (1907): Expéditions scientifiques du Travailleur et du Talisman. Céphalopodes 8: 313–353.
  2. ^ Hardy, A.C. (1956): The Open Sea: Its Natural History. Collins, London.
  3. ^ Vecchione, M.; Young, R. E. (1998). "The Magnapinnidae, a newly discovered family of oceanic squid (Cephalopoda: Oegopsida)". South African Journal of Marine Science 20 (1): 429–437. doi:10.2989/025776198784126340.  edit
  4. ^ Vecchione, M.; Young, R. E. (2006). "The squid family Magnapinnidae (Mollusca: Cephalopoda) in the Atlantic Ocean, with a description of a new species". Proceedings of the Biological Society of Washington 119 (3): 365–372. doi:10.2988/0006-324X(2006)119[365:TSFMMC]2.0.CO;2.  edit
  5. ^ a b c Guerra, A.; GonzáLez, A. F.; Rocha, F.; Segonzac, M.; Gracia, J. (2002). "Observations from submersibles of rare long-arm bathypelagic squids". Sarsia: North Atlantic Marine Science 87 (2): 189–192. doi:10.1080/003648202320205274.  edit
  6. ^ 'Mystery' squid delights scientists. BBC News, December 21, 2001.
  7. ^ a b c Hearn, K. (2008): Alien-like Squid With "Elbows" Filmed at Drilling Site. National Geographic News, November 24, 2008.
  8. ^ Bolstad, K. (2003): Deep-Sea Cephalopods: An Introduction and Overview. The Octopus News Magazine Online.
  • Vecchione, M.; Young, R.E.; Guerra, A.; Lindsay, D.J.; Clague, D.A.; Bernhard, J.M.; Sager, W.W.; Gonzalez, A.F.; Rocha, F.J. & Segonzac, M. (2001): Worldwide observations of remarkable deep-sea squids. Science 294(5551): 2505-2506. doi:10.1126/science.294.5551.2505 (HTML abstract)
  • Shuker, Karl P.N. (2002). The New Zoo: New and Rediscovered Animals of the Twentieth Century. House of Stratus (Thirsk).
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Magnapinna sp. C

Magnapinna sp. C is an undescribed species of bigfin squid known only from a single specimen of 79 mm mantle length (ML) collected in the southern Atlantic Ocean and held in the Natural History Museum. It is characterised by several morphological features: the proximal tentacles are more slender than arm pair IV, pigmentation is contained in the chromatophores, and "white nodules" are absent from the fins and glandular regions of the proximal tentacles.

Magnapinna sp. C was originally illustrated in The Open Sea in 1956 and identified as Octopodoteuthopsis.

References[edit]

  • Hardy, A. 1956. The Open Sea. Fisher, J., J. Gilmour, J. Huxley, M. Davies & E. Hosking (eds.), Collins, London.
  • Vecchione, M. & R.E. Young. 2006. The squid family Magnapinnidae (Mollusca; Cephalopoda) in the North Atlantic with a description of Magnapinna atlantica, n. sp.. Proc. Biol. Soc. Wash. 119(3): 365-372.
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Magnapinna sp. B

Magnapinna sp. B is an undescribed species of bigfin squid known only from a single immature specimen collected in the northern Atlantic Ocean. It is characterised by its dark epidermal pigmentation, which is epithelial, as opposed to the chromatophoral pigmentation found in other Magnapinna species.

The only known specimen of Magnapinna sp. B is a juvenile male of 95 mm mantle length (ML) held in the Bergen Museum. It was caught by the R/V G.O. SARS (MAR-ECO cruise super station 46, local station 374) on July 11, 2004, at 42°48′N 29°18′W / 42.8°N 29.3°W / 42.8; -29.3.

References [edit]

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