Pterygioteuthis giardi | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Cephalopoda |
Order: | Oegopsida |
Family: | Pyroteuthidae |
Genus: | Pterygioteuthis |
Species: | P. giardi |
Binomial name | |
Pterygioteuthis giardi | |
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). [3]
Squid in the family Pyroteuthidae have Photophores (small, light-producing organs) on viscera (internal organs), stalk of tentacles, and five large and ten small photophores underneath the eyes. [4]
The squid has a wide, triangular mantle with a rounded posterior end and rounded fins on the distal dorsal end of the mantle. [5] Their mantles are generally less than 34 mm long. [4]
Their tentacles look like bent clubs due to their permanent constriction. [6] Adult squid in the Pterygioteuthis genera lack hooks on their tentacular clubs, but do have some hooks on the arms.
Male squid have a specialized arm used to transfer sperm to females called hectocotyli. Females do not have suckers on their ventral arms and only have one oviduct developed. [4]
Squid in the Pyroteuthidae family live in the mesopelagic (midwater or twilight zone) during the day. At night, they migrate to the epipelagic waters (0-200m). [7]
There is little knowledge about the life history of these squid due to the difficulties in studying them, but research on P. gemmata estimated its maximum age to be 78 days, and it is presumed that others in the Pyroteuthidae family have similar life-spans. [8]
Similarly, there is little species-specific information about diet, but in a study of diets of cephalopods in the eastern Gulf of Mexico, it was found that P. giardi feed on small crustaceans such as copepods. [7]
P. giardi inhabits the Atlantic ocean between 40°N and 34°S and temperate regions (north and south) of the Pacific, but is not found in the eastern tropical Pacific. [4] Off the coast of Hawaii, P. giardi was found much more abundantly on the leeward (wind-protected) side of the inner boundary zone than the windward zone. Based on data from a study conducted in Hawaii, it was proposed that P. giardi might be a facultative-boundary species, which means that it can live in the boundary between the mesopelagic and neritic (coastal) zones but does not have to in order to survive. [9]
Predators of P. giardi vary by location but they include some large dolphins and fish. [10] In the south Pacific, a study of the diet of the Guadalupe Fur Seal showed that it also preys on P. giardi. [11]
In laboratory experiments, P. giardi has been observed to produce a luminescent flash when shocked with an electrode. It is likely that the squid use these flashes as a defense against predators. Organisms with photophores often also use luminescent flashes to attract prey or engage in mating rituals. [12]
P. giardi is also able to use Counter-illumination (break up their silhouette with light from photophores) under light conditions similar to those in the upper mesopelagic zone. [13]
P. giardi is a part of the P. giardi clade along with P. hoylei, which was originally classified as a subspecies of giardi, but was changed to species classification in 1987. P. giardi and P. hoylei are now recognized to be sister species. [4]
P. giardi is listed as a least concern species on the IUCN Red List. However, they list the need for further research into species-specific population size and dynamics, life history, ecology, and threats. [14]
Pyroteuthidae is a family of squids. The family comprises two genera. Species are diurnally mesopelagic, migrating into surface waters during the night. The family is characterised by the tentacles, which have a permanent constriction and bend near the base; and photophores occurring on the tentacles, eyeballs, and viscera. Members reach mantle lengths of 23–50 mm. Paralarvae of the family are common around the Hawaiian Islands, with up to 17% of collected specimens in the area belonging to Pyroteuthidae.
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. 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.
Helicocranchia pfefferi, the banded piglet squid, is a small squid of the genus Helicocranchia. Adults of this species are mesopelaegic.
Pterygioteuthis microlampas is a species of squid in the family Pyroteuthidae. They occur from northern New Zealand oceans to the Hawaiian Islands, but they do not overlap with the species P. gemmata, which lives in more southern waters. While there are numerous similarities between these two species, they are separated by the smaller mature size of P. microlampas and the fewer number of hooks on males. The species reproduce sexually during the late autumn to early winter, producing eggs with a diameter of 0.9 mm.
Pterygioteuthis gemmata is a species of squid in the family Pyroteuthidae.
Abraliopsis morisii is a species of bioluminescent squid in the family Enoploteuthidae. The species occurs in tropical to warm temperate waters in the Atlantic Ocean, including the Gulf of Mexico and the Mediterranean Sea. It can be found in the epipelagic and mesopelagic zones. Jean Baptiste Vérany described the species in 1839 and it reaches lengths of 25 to 33 millimetres. It is rated as least concern by the International Union for Conservation of Nature (IUCN).
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.
Heteroteuthis dispar, also known as the odd bobtail, is a small deep water squid found in the North Atlantic Ocean and the Mediterranean Sea.
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 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).
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, also 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 japonicus is a species of squid from the family Gonatidae. This species is restricted to the western North Pacific in the seas around the Japanese Archipelago.
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.
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 30mm. 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.
Nototeuthis is a monotypic genus of squid, in the family Neoteuthidae. The only species in this genus is Nototeuthis dimegacotyle . This species is characterised by short tentacular clubs, less than 40% of the length of the mantle, and relatively long fins, which are approximately 60% of the mantle length. The tentacle clubs have two greatly enlarged suckers on distal portion of the manus, which distinguish N. dimegacotyle from other members of the Neoteuthidae. Few specimens of this species are currently known. Specimens have been collected from the south eastern Pacific Ocean, off Chile, between the Southern Subtropical and the Antarctic Polar frontal zones. This species is mesopelagic to bathypelagic and can be found from near the surface to a depth of ~500m.
Eucleoteuthis is a monotypic genus of squid from the family Ommastrephidae; the only species is Eucleoteuthis luminosa, the striped flying squid or luminous flying 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.
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.
Pterygioteuthis hoylei is a species of squid in the family Pyroteuthidae. It is considered conspecific with Pterygioteuthis giardi by some authorities. It can be identified from P. giardi by having four photophores on the tentacles and many chromatophores spread along the tentacle stalk and around the aboral surface of the tentacular club. It is also slightly larger than P. giardi, it has been so far recorded only from the eastern tropical Pacific Ocean where it is the only species of in the family Pyroteuthidae to occur there, although its actual distribution may be wider than currently known. The specific name honours the British malacologist William Evans Hoyle (1855-1926).
A micronekton is a group of organisms of 2 to 20 cm in size which are able to swim independently of ocean currents. The word 'nekton' is derived from the Greek νήκτον, translit. nekton, meaning "to swim", and was coined by Ernst Haeckel in 1890.
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