Gonatus onyx

Last updated

Clawed armhook squid
Gonatus onyx.jpg
Gonatus onyx on the Davidson Seamount at 1,328 m depth.
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Oegopsida
Family: Gonatidae
Genus: Gonatus
Species:
G. onyx
Binomial name
Gonatus onyx
Young, 1972 [2]

Gonatus onyx is in the class Cephalopoda and in the phylum Mollusca. It is also known as the clawed arm hook squid or the black-eyed squid. It got these names from the characteristic black eye and from its two arms with clawed hooks on the end that extend a bit further than the other arms. It is a squid in the family Gonatidae, found most commonly in the northern Pacific Ocean from Japan to California. They are one of the most abundant cephalopods off the coast of California, mostly found at deeper depths, rising during the day most likely to feed.

Contents

The mantle size of Gonatus onyx has been known to reach up to 18 cm. G. onyx size varies from region to region, with larger members of the species being found in warmer areas.

The type specimen was collected off the coast of California and was deposited at the Santa Barbara Museum of Natural History. [3]

Range and habitat

Gonatus onyx is a very common cephalopod that is found in the Northern Pacific Ocean, ranging from coastal California to the east coast of Japan, and are found as far north as the Bering Sea. They are one of the most abundant cephalopods found in coastal California and are distributed with a latitude from 30°N to 43°N. [4] In these locations, they are typically found over the basin, shelf and shelf breaks, with a low variation in abundance. [5]

The adults and juveniles inhabit different areas, with the more solitary adults tending to like deeper water and the pack hunting juveniles preferring shallow coastal waters. They have one of the lowest seasonal variations over wide areas from the members of the family Gonatidae. The depth distribution is bimodal and follows a certain diel rhythm. [6] During the day they tend to stay at deeper depths with adults found from 400-1000m, with an average depth of around 700m. Younger members are found at 0-800m during the day with an average of around 400m. [7] During the night both adults and juveniles tend to rise from the deeper water. Adults at night have a range of depths from 100-800m with a large majority found around 400-500m. Juveniles have a smaller range from 0-500m and are more evenly spread out with most found from 0-300m. [4] When laying eggs, female G.onyx have been found at even deeper depths. They have been observed holding egg mass in their arms between 1500 and 2600m, with one female seen brooding an egg mass in Monterey Canyon at a depth of 1590m. [8]

Anatomy and morphology

Gonatus onyx is a relatively smaller-sized squid with an average mantle length of about 12 cm, with some warmer water individuals reaching up to 18 cm. This species shows sexual dimorphism in mantle size with females maturing faster and growing a couple of cm larger than the males. The mantle makes up a majority of their body length, the arms make up another about 40mm on average. They have characteristic black eyes on either side of their head, these highly developed sensory organs are helpful for hunting in pitch black conditions. The armature consists of five pairs, one pair with a large primary hook at the end and multiple rows of suckers, the other four pairs are generally shorter and do not have this tentacular hook, still lined with rows of suckers. The use of clawed arms are thought to be used in hunting and for better catching and handling of their prey. [4] Some individuals are harder to identify as the tentacular club is very fragile and easily damaged. The mantle’s fins are smaller than the other members of Gonatids and the tail is less tapered. G. onyx like most squid move using a propulsive force, using water expelled from a siphon with the combination of fin movements. The juvenile G. onyx has been observed using ink as a defensive mechanism and as a propulsive force, while the adults rarely use ink and rather choose to use a faster propulsive force. Matured members possess chromatophores, specialized small organs under the skin of the squid, which are used to change colors to hide reflective internal organs. They have a beak, like all cephalopods; it is relatively small compared to other species. The upper part of the beak is sharp and has less curvature, while the bottom is curved, duller, and shorter. This specialized beak makes it easier for squid to attack prey larger than themselves. [4]

Reproduction and post-spawning egg care

G. onyx, like most cephalopods, are oviparous organisms, meaning they lay eggs outside of their bodies. Females lay their eggs from April to July, brooding them for about six to nine months until the hatchlings are ready to emerge in depths exceeding 2,500 meters. [8] The extended duration dedicated to egg development and nurturing could potentially function as an evolutionary adaptation, facilitating the emergence of highly developed paralarvae. [9] These juveniles possess the ability to embark on extensive vertical migrations towards shallower waters abundant in nutrients. Throughout this gestation period, females sustain themselves with stored lipids from the digestive gland. [9] Like most squids, the species are believed to be semelparous animals, meaning they reproduce only once before perishing. [9]

To fertilize the female eggs, male squids employ specialized arms to deliver sperm packets, known as spermatophores, to the female’s seminal receptacle—a specialized internal oviduct near her mouth. Notably, female G. onyx exhibit a distinctive behavior: they cradle the egg mass with their hooked arms, a response to the loss of their tentacles post-fertilization, as they cannot feed while holding their eggs. [9] Once the egg masses are laid, females migrate to deep waters, a strategic move to evade potential predators. [8] Encased within a black jelly-like substance, the eggs reside in individual chambers connected by a delicate membrane. [9] Each egg is oval in shape, and range in size from 2.0 mm to 3.0 mm in length, and 1.8 mm to 2.1 mm in width. [9] Remarkably, a single egg mass can contain anywhere from 2,000 to 5,000 hatchlings. [8]

Early life and behavior

The hatchling’s physiology is very different from mature individuals. Hatching specimens collected were found to be moderately large at a total length of 5.0mm. The mantle length of these hatchlings ranged from 3.2mm-3.5mm and the width was 50-60% of the mantle length. Arms and tentacles are very different, there are 4 pairs of arms that are about 18-20% of the mantle size. Arm pairs 1 and 2 have suckers and sucker buds, arm pairs 3 and 4 lack suckers. There are one pair of tentacles that are proportionally larger than the arm pairs at around 40% of mantle length on average, they both contain a large number of sucker buds and the central hook is not yet visible. Hatchlings can be identified by a characteristic chromatophore pattern, with 5-6 in a single row on the aboral surface of the tentacles, a single pair on the base of the fins on the dorsal mantle, a single pair at the anterior end of the hatching gland on the mid-dorsal mantle, and 2-3 pairs on the lateral mantle. Hatchlings move with the hop-and-sink swimming style. Hatchlings mature into juveniles in about 3 months and are very active schooling predators during this time, they develop their hooks on arms and tentacles. Juveniles tend to school because they have less of a tendency to go after members of the same species when they are not fully developed. They are still relatively small with a dorsal mantle length of 30mm on average. Juveniles quickly accumulate lipids to prepare for reproduction, however, the exact reason for schooling is unknown. [10]

Adult life and behavior

Individuals older than about 3 months move to deeper waters and change their entire lifestyle. Adult G. Onyx are solitary hunters. As they make long vertical migrations during the night, they move closer to the surface to feed on other organisms that follow the same migration. Adults of this species have been known to be cannibalistic, with some studies indicating a rate as high as 42% of prey being of the same species. This cannibalistic behavior could serve as a reason for observed solitary behavior. Cannibalism could have evolved as a way to limit reproductive competition or as a result of low food availability in the deep waters. [11] This explains why cannibalism is more likely to occur where there are higher densities of competing squids for food. [11] Predators and prey from cannibalism tend to occur with individuals that are the same age and size as one another. [11] G. Onyx also preys on fish that are around the same size as the individual, mostly composed of Stenobrachius leucopsarus. The diet of juveniles is largely unknown with some studies finding a predominant crustacean diet and then a shift to nekton when mature. [11]

Adult and juvenile behavior differences are due to the difference in light penetration of the water from living in different depths. [12] Adults are opaque orange and white while juveniles are clear. Adults will change between these two colors as a defense mechanism during escape of potential predators. [12] Individuals were also observed to use ink as a form of shape mimicry. They release ink in long rope-like shapes that allow the squid to be mistaken as a different animal by predators so they can plan their escape. [13] Adults do not exhibit the fast defense behaviors seen in juveniles because they have less predation in the deeper waters and it requires more energy consumption which is a limited resource in the deep. [12]

Related Research Articles

<span class="mw-page-title-main">Squid</span> Superorder of cephalopod molluscs

A squid is a mollusc with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting these criteria. Like all other cephalopods, squid have a distinct head, bilateral symmetry, and a mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius or pen, made of chitin.

<span class="mw-page-title-main">Cephalopod</span> Class of mollusks

A cephalopod is any member of the molluscan class Cephalopoda such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot. Fishers sometimes call cephalopods "inkfish", referring to their common ability to squirt ink. The study of cephalopods is a branch of malacology known as teuthology.

<span class="mw-page-title-main">Giant squid</span> Deep-ocean dwelling squid in the family Architeuthidae

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. 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.

<span class="mw-page-title-main">Vampire squid</span> Species of cephalopod

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.

<span class="mw-page-title-main">Gonatidae</span> Family of squids

The Gonatidae, also known as armhook squid, are a family of moderately sized squid. The family contains about 19 species in three genera, widely distributed and plentiful in cold boreal waters of the Pacific Ocean. At least one species is known from Antarctic waters, and two from the North Atlantic. The genus Eogonatus was created for the species known as Eogonatus tinro because it did not have hooks on the tentacular club and it has 5 rows of teeth on the radula. Molecular studies in allozymes and mitochondrial DNA have indicated that this species nests within the genus Gonatus, although other authorities treat it as a synonym of Gonatopsis okutanii.

<i>Berryteuthis magister</i> Species of squid

Berryteuthis magister, also known as the magister armhook squid, commander squid or schoolmaster gonate squid, is a medium-sized squid in the family Gonatidae. It is found in cold, high latitude waters of the North Pacific where it is among the most numerous squid species recorded.

<span class="mw-page-title-main">Humboldt squid</span> Species of cephalopod

The Humboldt squid, also known as jumbo squid or jumbo flying squid (EN), and Pota in Peru or Jibia in Chile (ES), is a large, predatory squid living in the eastern Pacific Ocean. It is the only known species of the genus Dosidicus of the subfamily Ommastrephinae, family Ommastrephidae.

<i>Doryteuthis opalescens</i> Species of Cephalopoda

Doryteuthis opalescens, the opalescent inshore squid or market squid, is a small squid in the family Loliginidae. It is a myopsid squid, which is the near shore group and that means that they have corneas over their eyes. The species lives in the eastern Pacific Ocean from Mexico's Baja California peninsula to Alaska, United States, and as an inshore squid it can be found with a range of 200 miles (320 km) off the coast.

<i>Sepietta oweniana</i> Species of mollusc

Sepietta oweniana is a common marine mollusc from the order Sepiida, the cuttlefish.

<span class="mw-page-title-main">Cephalopod limb</span> Limbs of cephalopod molluscs

All cephalopods possess flexible limbs extending from their heads and surrounding their beaks. These appendages, which function as muscular hydrostats, have been variously termed arms, legs or tentacles.

<span class="mw-page-title-main">Neon flying squid</span> Species of squid

The neon flying squid, sometimes called the red flying squid, akaika, and red squid is a species of large flying squid in the family Ommastrephidae. They are found in subtropical and temperate oceanic waters globally.

<span class="mw-page-title-main">Bigfin reef squid</span> Species of squid

Sepioteuthis lessoniana, commonly known as the bigfin reef squid, tiger squid, glitter squid or oval squid, 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.

<i>Illex coindetii</i> Species of squid

Illex coindetii, commonly known as the southern shortfin squid or broadtail shortfin squid, is a species of neritic squids in the family Ommastrephidae. They are found in the Mediterranean Sea and on both sides of the north Atlantic Ocean.

<i>Teuthowenia megalops</i> Species of squid

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.

<i>Pinnoctopus cordiformis</i> Species of mollusc

Pinnoctopus cordiformis is a species of octopus found around the coasts of New Zealand. It is one of the most common species of octopus in the country.

Gonatopsis okutanii is a species of squid from the family Gonatidae from the northern Pacific Ocean. It is of uncertain taxonomic status, the presence of remnant tentacles on spent females indicate that this species does not belong in the genus Gonatopsis and the differences between this species and Gonatus makodai have led to some authorities stating that G. okutanii is a junior synonym of Eogonatus tinro. However the World Register of Marine Species still recognises Gonatopsis okutanii as the valid name for this taxon.

<span class="mw-page-title-main">European flying squid</span> Species of squid

The European flying squid is a species of squid from the continental slope and oceanic waters of the eastern Atlantic Ocean and the Mediterranean Sea. It is the type species of the genus Todarodes, the type genus of the subfamily Todarodinae of the pelagic squid family Ommastrephidae. It is a species which is targeted by some fisheries, although it is more often a bycatch.

<span class="mw-page-title-main">Gould's squid</span> Species of mollusc

Nototodarus gouldi, also known as the Gould's squid, Gould's flying squid, or arrow squid, is a squid belonging to the family Ommastrephidae. It inhabits the tropical and temperate waters of Australia and New Zealand. It is frequently caught and eaten for food. They live up to one year.

<i>Rossia</i> Genus of molluscs

Rossia is a genus of 10 species of benthic bobtail squid in the family Sepioidae found in all oceans. They live at depths greater than 50 m (164 ft) and can grow up to 9 cm in mantle length. This genus was first discovered in 1832 by Sir John Ross and his nephew James Clark Ross in the Arctic Seas, showing a resemblance to another genus under the same family, Sepiola. After returning from their expedition, Sir Richard Owen officially classified Rossia to be a new genus, naming it after Sir John and James Clark Ross.

References

  1. ↑ Barratt, I.; Allcock, L. (2014). "Gonatus onyx". IUCN Red List of Threatened Species . 2014: e.T162950A957015. doi: 10.2305/IUCN.UK.2014-1.RLTS.T162950A957015.en . Retrieved 18 November 2021.
  2. ↑ Julian Finn (2016). "Gonatus onyx Young, 1972". World Register of Marine Species . Flanders Marine Institute . Retrieved 6 March 2018.
  3. ↑ Current Classification of Recent Cephalopoda
  4. 1 2 3 4 Hunt, J. C.; Seibel, B. A. (2000-04-01). "Life history of Gonatus onyx (Cephalopoda: Teuthoidea): ontogenetic changes in habitat, behavior and physiology". Marine Biology. 136 (3): 543–552. Bibcode:2000MarBi.136..543H. doi:10.1007/s002270050714. ISSN   1432-1793. S2CID   84763064.
  5. ↑ Jorgensen, Elaina M. (2007-05-01). "Identification, distribution and relative abundance of paralarval gonatid squids (Cephalopoda: Oegopsida: Gonatidae) from the Gulf of Alaska, 2001–2003". Journal of Molluscan Studies. 73 (2): 155–165. doi:10.1093/mollus/eym010. ISSN   1464-3766.
  6. ↑ Watanabe, Hikaru; Kubodera, Tsunemi; Moku, Masatoshi; Kawaguchi, Kouichi (2006-06-13). "Diel vertical migration of squid in the warm core ring and cold water masses in the transition region of the western North Pacific". Marine Ecology Progress Series. 315: 187–197. Bibcode:2006MEPS..315..187W. doi: 10.3354/meps315187 . ISSN   0171-8630.
  7. ↑ admin (2020-03-17). "Running the gauntlet— Deep-sea animals face multiple dangers in their daily migration".{{cite journal}}: Cite journal requires |journal= (help)
  8. 1 2 3 4 Seibel, Brad A.; Robison, Bruce H.; Haddock, Steven H. D. (December 2005). "Post-spawning egg care by a squid". Nature. 438 (7070): 929. Bibcode:2005Natur.438..929S. doi:10.1038/438929a. ISSN   1476-4687.
  9. 1 2 3 4 5 6 Seibel, B. A.; Hochberg, F. G.; Carlini, D. B. (2000-10-01). "Life history of Gonatus onyx (Cephalopoda: Teuthoidea): deep-sea spawning and post-spawning egg care". Marine Biology. 137 (3): 519–526. Bibcode:2000MarBi.137..519S. doi:10.1007/s002270000359. ISSN   1432-1793.
  10. ↑ "Advances in Marine Biology", Advances in Marine Biology Volume 60, vol. 60, Elsevier, 2011, pp. iii, doi:10.1016/b978-0-12-385529-9.00007-x, ISBN   9780123855299 , retrieved 2022-04-22
  11. 1 2 3 4 Hoving, H.J.T.; Robison, B.H. (October 2016). "Deep-sea in situ observations of gonatid squid and their prey reveal high occurrence of cannibalism". Deep Sea Research Part I: Oceanographic Research Papers. 116: 94–98. doi:10.1016/j.dsr.2016.08.001. ISSN   0967-0637.
  12. 1 2 3 Hunt, J. C.; Seibel, B. A. (2000-04-01). "Life history of Gonatus onyx (Cephalopoda: Teuthoidea): ontogenetic changes in habitat, behavior and physiology". Marine Biology. 136 (3): 543–552. doi:10.1007/s002270050714. ISSN   1432-1793.
  13. ↑ Bush, Stephanie L.; Robison, Bruce H. (2007-09-01). "Ink utilization by mesopelagic squid". Marine Biology. 152 (3): 485–494. doi:10.1007/s00227-007-0684-2. ISSN   1432-1793.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.