Histioteuthis heteropsis

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Strawberry Squid
Cock-Eyed Squid.JPG
Black and white picture of a Histioteuthis heteropsis, also known as the strawberry squid, at the Monterey Bay Aquarium on June 27, 2014.
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Oegopsida
Family: Histioteuthidae
Genus: Histioteuthis
Species:
H. heteropsis
Binomial name
Histioteuthis heteropsis
(Berry, 1913 )
Synonyms

Calliteuthis heteropsis(Berry, 1913 )

Histioteuthis heteropsis, known as the strawberry squid, is a species of small cock-eyed squid. [2] The scientific nomenclature of these squid stems from their set of differently sized eyes, one being small and blue and the other being large and yellow. It is thought that the large eye is used to see objects against dim light, while the smaller eye is more able to view bioluminescent light sources. [3] The squid's vernacular name arose due to its rich red skin pigmentation and the presence of photophores along its body, making it appear like a strawberry with seeds. [2]

Contents

H. heteropsis live in the ocean's mesopelagic zone and are found in the California Current and the Humboldt Current. [4] Little is known about their specific feeding and mating behaviors, although their inking patterns have been subject to study. [4] They are not easily disturbed and only ink when provoked. [5]

H. heteropsis was discovered by Berry in 1913 and exhibited publicly for the first time at the Monterey Bay Aquarium on June 27, 2014. [6]

Description

Members of the species H. heteropsis are small squids, with mature males averaging 54–89 mm in length, and have a purplish-red skin pigment. [4]

Eyes

The eyes of H. heteropsis are dimorphic both in size and in lens pigmentation for specialized vision in the ocean's mesopelagic zone (200–1000 meters below the ocean surface). [3] The different properties of the squid's eyes allow it to see a variety of different light sources present in its habitat, primarily downwelling sunlight and bioluminescence. [3] H. heteropsis hatchlings are born with identical eyes of the same size and pigmentation. [3] As they develop, the left eye becomes larger and more pigmented. [3] By adulthood, the left eye can grow to be over twice the size of the right eye and has a distinct yellow lens pigmentation. [3] In a 2017 study conducted by Kate Thomas, Bruce Robinson, and Sönke Johnsen, it was found that the large left yellow eye is oriented upwards for viewing objects in dim sunlight and the smaller right blue eye is oriented downwards for viewing bioluminescence. [3] While the larger eye can detect bioluminescence fairly well, the smaller eye struggles to view black objects in dim light. [3]

Photophores

Small photophores, which are glandular, light-producing organs, are found in high concentrations along the entire body of H. heteropsis. [7] The photophores are more dense near the anterior head region of the squid and become smaller and farther apart near the posterior end. [7] Apart from  H. meleagroteuthis, H. heteropsis is the only member in the family Histioteuthidae to display such small and highly concentrated photophores. [7] H. heteropsis mainly uses its photophores for two purposes: counter-illumination and concealing prey. [8] In counter-illumination, the squid produces blue light from its photophores so that, when viewed from above, it blends in with the downwelling sunlight and effectively erases its silhouette. [8] This type of bioluminescence is characterized by consistent light production, in contrast to bioluminescence used for concealing prey, which is characterized by short bursts of intense light or "flashes". [8] Although the exact purpose for this particular use of bioluminescence is unknown, the heavily pigmented oral cavity and interbrachial membrane of H. heteropsis and some other squids suggests that luminescence by the prey threatens the predator in some way. [8]

Reproductive organs

H. heteropsis males do not possess a hectocotylus as is common in other mesopelagic squid species, although they do have a penis which is used to transfer spermatophores to the female during copulation. [4] During maturation, the penis grows until it can extend out of the mantle cavity. [4] The spermatophores of H. heteropsis have short sperm masses and are stored in a looped Needham's sac. [7] Female H. heteropsis squids have a singular ovary where the oocytes are developed. [9] Although not much is known about female reproductive systems in H. heteropsis specifically, other members of the family Histioteuthidae show significant oocyte resorption (oosorption) during maturation. [10]

Habitat

H. heteropsis is generally found at ocean depths of 200–1000 meters (0.12–0.62 miles), which is considered part of the ocean's mesopelagic, or twilight, zone. [3] The species undergoes diurnal vertical migration, where they are found at lower depths during the day and migrate up the water column at night. [11] In a study about vertical distributions of pelagic cephalopods conducted by Clyde Roper and Richard Young, it was found that, during the day, most H. heteropsis specimens were found at 500–700 meters while at night, most were found at 300–400 meters. [11]

H. heteropsis live in the Pacific Ocean and are predominantly found in the California Current and the Humboldt Current. [4] Population distribution of H. heteropsis is better known in the California Current than it is in the Humboldt Current and the species does not inhabit waters close to the equator. [4] There is no evidence to suggest horizontal migration in histioteuthid squids, including H. heteropsis. [4]

Within marine food webs, H. heteropsis plays an important role in the diets of tuna, porpoises, blue sharks, sperm whales, elephant seals, and albatross. [4] Not much is known about the diet of H. heteropsis itself, although limited stomach content evaluations show that they feed on fish, crustaceans, and smaller squids. [4]

Behavior

Feeding

H. heteropsis searches for prey using visual clues and strikes forward at the prey using their tentacles. [9] The tentacles then bring the prey within range of the arms, which hold the prey in place with suckers. [9] H. heteropsis, like most squids, bite immediately into the fleshy parts of the prey with their beak and release the leftover corpse. [9]

Mating

Very little is known about mating and courtship in H. heteropsis, although it is likely that these behaviors occur in deeper waters. [4] Spawning may occur in deep-midwater or near-surface waters, but it is still unclear. [4]

Inking

Inking developed as an important protective mechanism for coleoid cephalopods after losing their ancestral external shell. [5] However, inking is metabolically costly since it requires the discharge of both melanin and mucus. [5] Because of this, H. heteropsis typically only inks when approached closely or touched. [5] Researchers Stephanie Bush and Bruce Robinson observed that H. heteropsis most often produces an ink cloud categorized as "pseudomorphs", which are "dense blobs of ink the approximate shape and size of the individual releasing them." [5] In all instances of inking, H. heteropsis specimens lingered in the ink cloud unless further provoked. [5]

Taxonomy

In 1913, Berry discovered H. heteropsis and recognized it as a member of the family Histioteuthidae due to its large number of photophores. [7] Based on significant morphological traits, it appears that H. heteropsis is most closely related to H. meleagroteuthis and H. bonnellii. [7]

Conservation status

Based on a 2010 assessment by the International Union for Conservation of Nature (IUCN), H. heteropsis is categorized as least concern due to its large geographic distribution. [12] There are no known threats to the species and population information is not available. [12] The IUCN recommends that more research be done into H. heteropsis to determine details about its population and ecological role. [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 orders Myopsida, Oegopsida, and Bathyteuthida. 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.

<i>Histioteuthis</i> Genus of cephalopods known as cock-eyed squids

Histioteuthis is a genus of squid in the family Histioteuthidae. It goes by the common name cock-eyed squid, because in all species the right eye is normal-sized, round, blue and sunken; whereas the left eye is at least twice the diameter of the right eye, tubular, yellow-green, faces upward, and bulges out of the head.

<span class="mw-page-title-main">Histioteuthidae</span> Family of cephalopods

Histioteuthidae is a family of Oegopsid squid. The family was previously considered to be monotypic but the World Register of Marine Species assigns two genera to this family.

<span class="mw-page-title-main">Firefly squid</span> Species of cephalopod also known as the sparkling enope squid

The firefly squid, also commonly known as the sparkling enope squid or hotaru-ika in Japan, is a species of squid in the family Enoploteuthidae. W. scintillans is the sole species in the monotypic genus Watasenia.

<span class="mw-page-title-main">Blackbelly lanternshark</span> Species of shark

The blackbelly lanternshark or lucifer shark is a shark of the family Etmopteridae found around the world in tropical and temperate seas at depths between 150 and 1,250 meters – the mesopelagic zone. Compared to other mesopelagic fish predators and invertebrates, the blackbelly lanternshark is thought to reside in shallower, more southern waters. E. lucifer can reach up to 47 centimeters in length and consumes mesopelagic cephalopods, fish, and crustaceans. Blackbelly lanternsharks are bioluminescent, using hormone controlled mechanisms to emit light through ventral photogenic organs called photophores and are presumed to be ovoviviparous. The blackbelly lanternshark has been classified as "Not Threatened" within the New Zealand Threat Classification System.

<i>Sandalops melancholicus</i> Species of squid

Sandalops melancholicus, the sandal-eyed squid or melancholy cranch squid, is a small species of glass squid. It is known to reach a mantle length of 11 cm (4.3 in). It is distributed in the tropical and subtropical oceans around the world. It is the only species in the genus Sandalops but some authorities suggest that this may be a species complex rather than a monotypic genus.

<i>Helicocranchia pfefferi</i> Species of squid

Helicocranchia pfefferi, the banded piglet squid, is a small squid of the genus Helicocranchia. Adults of this species are mesopelaegic.

<i>Onychoteuthis banksii</i> Species of squid

Onychoteuthis banksii, the common clubhook squid, is a species of squid in the family Onychoteuthidae. It is the type species of the genus Onychoteuthis. This species was thought to have a worldwide distribution but with the revision of the genus Onychoteuthis in 2010, it is now accepted that Onychoteuthis banksii is restricted to the central and northern Atlantic and the Gulf of Mexico while a recently described species, Onychoteuthis horstkottei, is found in the Pacific Ocean. The type locality is the Gulf of Guinea.

<i>Histioteuthis bonnellii</i> Species of cephalopod

Histioteuthis bonnellii, the umbrella squid, is a species of cock-eyed squid belonging to the family Histioteuthidae.

<i>Histioteuthis reversa</i> Species of squid

Histioteuthis reversa, commonly known as the reverse jewel squid or the elongate jewel squid, is a species of cock-eyed squid, so called because the eyes are dissimilar. It occurs at moderate depths in the Atlantic Ocean and the Mediterranean Sea. It is also known from the Indian Ocean.

Stigmatoteuthis arcturi, commonly known as the jewelled squid, is a species of cock-eyed squid from the family Histioteuthidae. It occurs throughout the subtropical and tropical Atlantic Ocean in the mesopelagic zone.

<i>Pterygioteuthis giardi</i> Species of squid

Pterygioteuthis giardi is a species of squid in the family Pyroteuthidae. It is known as the roundear enope squid. The specific name honors the French zoologist and marine biologist Alfred Mathieu Giard (1846-1908).

Teuthowenia pellucida, the googly-eyed glass squid, is a rare deep-sea glass squid whose habitat ranges throughout the oceans of the Southern Hemisphere.

<span class="mw-page-title-main">Counter-illumination</span> Active camouflage using light matched to the background

Counter-illumination is a method of active camouflage seen in marine animals such as firefly squid and midshipman fish, and in military prototypes, producing light to match their backgrounds in both brightness and wavelength.

<i>Galiteuthis glacialis</i> Species of squid

Galiteuthis glacialis is a species of glass squid from the Antarctic Convergence. It is in the cranchiidae family and subfamily taoniinae. They are endemic to the Antarctic and are found in the Southern Ocean, around the Weddell Sea and the South Shetland Islands. Galiteuthis glacialis are one of the most plentiful and widely dispersed species of Antarctic squid. These squids are found in the mesopelagic and bathypelagic layers of the open ocean and demonstrate vertical migration. They can reach a maximum mantle length of 500 mm (0.5m).

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

Abralia veranyi is a species of squid in the family Enoploteuthidae. Common names include the eye-flash squid, Verany's enope squid and the midwater squid. It is found in the Atlantic Ocean and the Mediterranean Sea. It undergoes a daily vertical migration from deep waters to near the surface.

Lampadioteuthis megaleia is a small, colorful squid, the only species in the only genus in the monotypic family Lampadioteuthidae. It is sometimes known as the wonderful firefly squid. It was formerly classified in the family Lycoteuthidae, but differs from them mainly by having a hectocotylus in the males and by the possession of a rostrum on the gladius.

<i>Ornithoteuthis antillarum</i> Species of squid

Ornithoteuthis antillarum, the Atlantic bird squid, is a species of flying squid from the family Ommastrephidae which is found in the warmer waters of the Atlantic Ocean. This species is an important component of the diet of many species of fish and of cetaceans. It is taken as a bycatch in fisheries but has the potential to be commercially important if appropriate fishing methods can be developed.

<i>Neoscopelus macrolepidotus</i> Species of fish

Neoscopelus macrolepidotus, also known as a large-scaled lantern fish, is a species of small mesopelagic or bathypelagic fish of the family Neoscopelidae, which contains six species total along three genera. The family Neoscopelidae is one of the two families of the order Myctophiformes. Neoscopelidae can be classified by the presence of an adipose fin. The presence of photophores, or light-producing organs, further classify the species into the genus Neoscopelus. N. macrolepidotus tends to be mesopelagic until the individuals become large adults, which is when they settle down to the bathypelagic zone.

Histioteuthis meleagroteuthis is a species of small to medium squids that have a dark, wine-red skin pigment. Females at maturity average at 114 mm (4.5 in) in length, while males at maturity average at 65 to 102 mm in length. This species is characterized by tubercles, photophores, and asymmetric features. This species can be found in circumglobal, mesopelagic waters.

References

  1. Barratt, I.; Allcock, L. (2014). "Histioteuthis heteropsis". IUCN Red List of Threatened Species . 2014: e.T162925A953880. doi: 10.2305/IUCN.UK.2014-1.RLTS.T162925A953880.en . Retrieved 18 November 2021.
  2. 1 2 "Multimedia Gallery - Cockeyed squid (Histioteuthis heteropsis) | NSF - National Science Foundation". www.nsf.gov. Retrieved 2020-07-22.
  3. 1 2 3 4 5 6 7 8 9 Thomas, Kate N.; Robison, Bruce H.; Johnsen, Sönke (2017-04-05). "Two eyes for two purposes: in situ evidence for asymmetric vision in the cockeyed squids Histioteuthis heteropsis and Stigmatoteuthis dofleini". Phil. Trans. R. Soc. B. 372 (1717): 20160069. doi:10.1098/rstb.2016.0069. ISSN   0962-8436. PMC   5312019 . PMID   28193814.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 Voss, N. A.; Sweeney, M. J. (1998). "Systematics and Biogeography of cephalopods. Volume II". Smithsonian Contributions to Zoology (586): 277–599. doi:10.5479/si.00810282.586.277. ISSN   0081-0282.
  5. 1 2 3 4 5 6 Bush, Stephanie L.; Robison, Bruce H. (2007-06-26). "Ink utilization by mesopelagic squid". Marine Biology. 152 (3): 485–494. doi:10.1007/s00227-007-0684-2. ISSN   0025-3162. S2CID   84629175.
  6. "We have a new visitor from the deep in our Tentacles special exhibition: the cock-eyed squid!". MBA Tumblr. Monterey Bay Aquarium. June 27, 2014. Retrieved March 29, 2016.
  7. 1 2 3 4 5 6 Voss, Nancy A. (1969). "Biological investigations of the deep sea. 47. A monograph of the Cephalopoda of the North Atlantic. The family Histioteuthidae". Bulletin of Marine Science. 19 (4): 713–867 via Ingenta Connect.
  8. 1 2 3 4 Young, Richard Edward (1983). "Oceanic bioluminescence: an overview of general functions". Bulletin of Marine Science. 33 (4): 829–845 via Ingenta Connect.
  9. 1 2 3 4 Barord, Gregory Jeff; Boyle, P. (2019), "Cephalopods", Encyclopedia of Ocean Sciences, Elsevier, pp. 516–522, doi:10.1016/b978-0-12-409548-9.11604-5, ISBN   978-0-12-813082-7
  10. Laptikhovsky, Vladimir (2001-06-30). "First data on ovary maturation and fecundity in the squid family Histioteuthidae". Scientia Marina. 65 (2): 127–129. doi: 10.3989/scimar.2001.65n2127 . ISSN   1886-8134.
  11. 1 2 Roper, Clyde F. E.; Young, R. E. (1975). "Vertical distribution of pelagic cephalopods" (PDF). Smithsonian Contributions to Zoology (209): 1–51. doi:10.5479/si.00810282.209. ISSN   0081-0282.
  12. 1 2 3 Barratt (SRLI), Iain; Allcock (SRLI), Louise (2010-05-05). "IUCN Red List of Threatened Species: Histioteuthis heteropsis". IUCN Red List of Threatened Species. doi: 10.2305/iucn.uk.2014-1.rlts.t162925a953880.en . Retrieved April 10, 2023.

Further reading