Reverse jewel squid | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Cephalopoda |
Order: | Oegopsida |
Family: | Histioteuthidae |
Genus: | Histioteuthis |
Species: | H. reversa |
Binomial name | |
Histioteuthis reversa | |
Synonyms [2] | |
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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.
Histioteuthis reversa grows to a mantle length of about 19 cm (7.5 in). The head bears four pairs of robust arms, a pair of tentacles and two unequal-sized eyes and the main body mass is enclosed in the mantle. The arms are less than one and a half times the length of the mantle. The outer arms are not joined to each other by a web and the inner arms are connected by a vestigial web remnant. The suckers on the arms are globular, usually with teeth on the margin, and the suckers on the terminal portion of the tentacles are in five or six rows, with larger suckers in the central rows. The mantle is cup-shaped and elongates considerably in females when they mature. The fins are a third to a half the length of the mantle and roughly half its width. The ventral (under) surface of the mantle has a complex arrangement of large and small compound light-emitting photophores, and seventeen large and one small photophore surround the right eye. In front of the left eye there are seven large photophores and the eye is ringed by ten to fourteen small ones. [3] [4]
Histioteuthis reversa is native to the Atlantic Ocean and the Mediterranean Sea. It is mostly found in the northern hemisphere but also occurs off the coast of Namibia and South Africa. The northern limit of its range is the Newfoundland and the seas south of Iceland at 52° North. It does not occur in the Gulf of Mexico and is uncommon in the Caribbean Sea. It has been recorded in the southern Indian Ocean. It is found in the upper waters of the open sea, [5] often at depths of between 600 and 800 m (1,969 and 2,625 ft), [6] and frequently in the vicinity of seamounts and other undersea features, perhaps because primary production is greater in these areas. [3] [4]
Little is known of the behaviour and ecology of this squid but it seems to breed over the continental slope as juveniles in the size range 2 to 4 cm (0.8 to 1.6 in) have been found there. Adults are eaten by various cetaceans including sperm whales (Physeter macrocephalus), pygmy sperm whales (Kogia breviceps) [5] and Risso's dolphin (Grampus griseus), a fact confirmed by examining the stomach contents of stranded animals among which the indigestible beaks of the squids are found. [6]
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.
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.
Risso's dolphin is a dolphin, the only species of the genus Grampus. Some of the closest related species to these dolphins include: pilot whales, pygmy killer whales, melon-headed whales, and false killer whales.
Ancistrocheirus lesueurii, the sharpear enope squid, is the only species in the genus Ancistrocheirus and family Ancistrocheiridae. With a mantle length of 25 cm (9.8 in), this moderately sized squid may be found throughout the tropical and subtropical oceans. They tend to be found at mesopelagic depths.
The Chiroteuthidae are a family of deep-sea squid, generally small to medium in size, rather soft and gelatinous, and slow moving. They are found in most temperate and tropical oceans, but are known primarily from the North Atlantic, North Pacific, and Indo-Pacific. The family is represented by approximately 12 species and four subspecies in four genera, two of which are monotypic. They are sometimes known collectively as whip-lash squid, but this common name is also applied to the Mastigoteuthidae, which are sometimes treated as a subfamily (Mastigoteuthinae) of Chiroteuthidae.
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.
Doryteuthis plei, also known as the slender inshore squid or arrow squid, is a medium-sized squid belonging to the family Loliginidae. It occurs abundantly in coastal waters of the Atlantic Ocean, from Argentina northward to North Carolina.
Histioteuthis bonnellii, the umbrella squid, is a species of cock-eyed squid belonging to the family Histioteuthidae.
The colossal squid is the largest member of its family Cranchiidae, the cockatoo or glass squids, with its second largest member being Megalocranchia fisheri. It is sometimes called the Antarctic cranch squid or giant squid and is believed to be the largest squid species in terms of mass. It is the only recognized member of the genus Mesonychoteuthis and is known from only a small number of specimens. The species is confirmed to reach a mass of at least 495 kilograms (1,091 lb), though the largest specimens—known only from beaks found in sperm whale stomachs—may perhaps weigh as much as 600–700 kilograms (1,300–1,500 lb), making it the largest known invertebrate. Maximum total length has been estimated between 10 metres (33 ft) and 14 metres (46 ft) but the former estimate is more likely. The colossal squid has the largest eyes of any known creature ever to exist, with an estimated diameter of 27–30 cm (11–12 in) to 40 cm (16 in) for the largest collected specimen.
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.
Heteroteuthis dispar, also known as the odd bobtail, is a small deep water squid found in the North Atlantic Ocean and the Mediterranean Sea.
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.
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.
Histioteuthis heteropsis, known as the strawberry squid, is a species of small cock-eyed squid. 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. 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.
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.
Gonatopsis borealis, the Boreopacific armhook squid, is a species of squid from the North Pacific Ocean. It is a member of the family Gonatidae. It is an abundant species which is currently caught mainly as a bycatch by fishing boats targeting other quarry. It is an important prey species for many commercially important species of fish, as well as for marine mammals.
Nematolampas regalis, the regal firefly squid is a small, little-known species of squid from the family Lycoteuthidae which is found in the subtropical South Pacific Ocean. This squid has a mantle length of 30 mm (1.2 in). It may be sexually dimorphic, with the males possibly having very thin elongated arms III, which are increasingly thread like towards their tips, where they do not have any suckers. Arms II are "normal" and have suckers along their length. The third arms have a series of photophores along their length, and there is a small photophore located on each of the tips of arms I and II. The tentacles have two embedded photophores and the largest of the eye's photophores is in the centre. There is a pair of large photophores close to the tip of the mantle on the ventral side mantle, with no other photophores on the body except for a visceral photophore which is also near the tip. There is practically no tail.
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.
Ornithoteuthis volatilis, the shiny bird squid, is a squid from the subfamily Ommastrephinae, the flying squids, of the family Ommastrephidae part of the pelagic squid order Oegopsida. It is a tropical and sub-tropical species which is widely distributed in the Indo-Pacific oceans. It is slightly larger than the closely related species Ornithoteuthis antillarum of the Atlantic Ocean.
The Antarctic flying squid is a species of squid from the subfamily Todarodinae of the family Ommastrephidae, a family of pelagic squid from the order Oegopsida. It has a circumglobal distribution in the seas around the lower latitudes of the Southern Ocean.