Doryteuthis plei

Slender inshore squid
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Order:	Myopsida
Family:	Loliginidae
Genus:	Doryteuthis
Subgenus:	Doryteuthis
Species:	D. plei
Binomial name
	Doryteuthis plei; (Blainville, 1823) [1]
Synonyms [1]
	Loligo pleiBlainville, 1823;

Last updated March 25, 2019

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.

Squid are cephalopods in the superorder Decapodiformes with elongated bodies, large eyes, eight arms and two tentacles. 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.

Loliginidae, commonly known as pencil squids, is an aquatic family of squid classified in the order Myopsida.

The Atlantic Ocean is the second largest of the world's oceans, with an area of about 106,460,000 square kilometers. It covers approximately 20 percent of the Earth's surface and about 29 percent of its water surface area. It separates the "Old World" from the "New World".

Description

As both common names imply, these squid have elongate, cylindrical bodies with a length to width ratio of 7:1. The arms are in contrast short and weak; the two tentacles are somewhat less than the mantle length. The rhombus-shaped fins are large, up to about 50 percent of the mantle length. Running the ventral length of the mantle is a noticeable ridge. The squid are a reddish orange colour with a large complement of chromatophores.

Tentacle varied organ found in many animals and used for palpation and manipulation

In zoology, a tentacle is a flexible, mobile, elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work mainly like muscular hydrostats. Most forms of tentacles are used for grasping and feeding. Many are sensory organs, variously receptive to touch, vision, or to the smell or taste of particular foods or threats. Examples of such tentacles are the "eye stalks" of various kinds of snails. Some kinds of tentacles have both sensory and manipulatory functions.

The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.

Rhombus quadrilateral in which all sides have the same length

In plane Euclidean geometry, a rhombus is a simple (non-self-intersecting) quadrilateral whose four sides all have the same length. Another name is equilateral quadrilateral, since equilateral means that all of its sides are equal in length. The rhombus is often called a diamond, after the diamonds suit in playing cards which resembles the projection of an octahedral diamond, or a lozenge, though the former sometimes refers specifically to a rhombus with a 60° angle, and the latter sometimes refers specifically to a rhombus with a 45° angle.

The suckers of the arms possess blunt teeth. On the meaty ends (clubs) of the tentacles, there are four rows of suckers; the inner two (mesial) rows are three times as large as the outer two (marginal) rows. The larger suckers have horny rings with up to 45 teeth.

These squid reach a maximum mantle length of 33 centimetres in males and 22 centimetres in females. Sexual dimorphism is apparent, with the left ventral arm in males modified into a hectocotylus; this is used to facilitate fertilization during mating. Males also have a number of purple stripes running lengthwise on the ventral side of the mantle; along with other visual cues produced by chromatophores, these stripes are used in elaborate courtship displays.

Sexual dimorphism is the condition where the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs. The condition occurs in many animals and some plants. Differences may include secondary sex characteristics, size, weight, color, markings, and may also include behavioral and cognitive differences. These differences may be subtle or exaggerated, and may be subjected to sexual selection. The opposite of dimorphism is monomorphism.

A hectocotylus is one of the arms of male cephalopods that is specialized to store and transfer spermatophores to the female. Structurally, hectocotyli are muscular hydrostats. Depending on the species, the male may use it merely as a conduit to the female, or he may wrench it off and present it to the female.

Ecology

Due to their abundance, slender inshore squid are important to both commercial and subsistence fisheries. During the annual summer mating season, the squid congregate in large numbers near shore. During the austral summer in waters off Brazil, annual catches may reach 763 metric tonnes.

Brazil, officially the Federative Republic of Brazil, is the largest country in both South America and Latin America. At 8.5 million square kilometers and with over 208 million people, Brazil is the world's fifth-largest country by area and the fifth most populous. Its capital is Brasília, and its most populated city is São Paulo. The federation is composed of the union of the 26 states, the Federal District, and the 5,570 municipalities. It is the largest country to have Portuguese as an official language and the only one in the Americas; it is also one of the most multicultural and ethnically diverse nations, due to over a century of mass immigration from around the world.

While there may be safety in their numbers, the squid are an important prey item for large fish such as tuna and sharks and a number of cetaceans: pygmy killer whales, orcas, Atlantic spotted dolphins, rough-toothed dolphins, and bottlenose dolphins are all known predators of slender inshore squid. Other predators include South African and Antarctic fur seals.

Fish are gill-bearing aquatic craniate animals that lack limbs with digits. They form a sister group to the tunicates, together forming the olfactores. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Tetrapods emerged within lobe-finned fishes, so cladistically they are fish as well. However, traditionally fish are rendered paraphyletic by excluding the tetrapods. Because in this manner the term "fish" is defined negatively as a paraphyletic group, it is not considered a formal taxonomic grouping in systematic biology, unless it is used in the cladistic sense, including tetrapods. The traditional term pisces is considered a typological, but not a phylogenetic classification.

A tuna is a saltwater fish that belongs to the tribe Thunnini, a subgrouping of the Scombridae (mackerel) family. The Thunnini comprise 15 species across five genera, the sizes of which vary greatly, ranging from the bullet tuna up to the Atlantic bluefin tuna. The bluefin averages 2 m (6.6 ft), and is believed to live up to 50 years.

Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimorpha and are the sister group to the rays. However, the term "shark" has also been used for extinct members of the subclass Elasmobranchii outside the Selachimorpha, such as Cladoselache and Xenacanthus, as well as other Chondrichthyes such as the holocephalid eugenedontidans.

The squid prey upon several species of estuarine fish, including: killifish, mosquitofish and mollies. Small crustaceans such as grass shrimp are also taken.

Killifish Any of various oviparous cyprinodontiform fish

A killifish is any of various oviparous (egg-laying) cyprinodontiform fish. All together, there are some 1270 different species of killifish, the biggest family being Rivulidae, containing more than 320 species. Because of living in ephemeral waters, the eggs of most killifish can survive periods of partial dehydration. Many of the species rely on such a diapause, since the eggs would not survive more than a few weeks if entirely submerged in water. Like seeds, the eggs can be sent by mail without water. The adults of some species, such as Kryptolebias marmoratus, can additionally survive out of the water for several weeks. Most killies are small fish, from one to two inches, with the largest species growing to just under six inches (15 cm).

The western mosquitofish and eastern mosquitofish are a species of freshwater fish, also known commonly, if ambiguously, as simply mosquitofish or by its generic name, Gambusia, or by the common name gambezi.

Poecilia is a genus of fishes in the family Poeciliidae of the order Cyprinodontiformes. These livebearers are native to fresh, brackish and salt water in the Americas, and some species in the genus are euryhaline. A few have adapted to living in waters that contain high levels of toxic hydrogen sulfide and a population of P. mexicana lives in caves.

Related Research Articles

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.

Ommastrephidae is a family of squid containing three subfamilies, 11 genera, and over 20 species. They are widely distributed globally and are extensively fished for food. One species, Todarodes pacificus, comprises around half of the world's cephalopod catch annually.

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.

Longfin inshore squid species of mollusc

The longfin inshore squid is a species of squid of the family Loliginidae.

The European squid or common squid is a large squid belonging to the family Loliginidae. It occurs abundantly in coastal waters from the North Sea to at least the west coast of Africa. This species lives from sea level to depths of 500 m (1,600 ft). Its mantle is up to 40 cm (16 in) long. The species is extensively exploited by commercial fisheries.

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

Doryteuthis opalescens, the opalescent inshore 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>Idioteuthis cordiformis</i> species of mollusc

Idioteuthis cordiformis is a species of whip-lash squid found in tropical regions of the west Pacific Ocean. The species is commonly known as the 'love-heart squid' because the species name cordiformis is Latin for 'heart shaped'. Recently, this species has been found to consume shark.

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 Mediterranean Sea and is also known from the Indian Ocean.

Lolliguncula brevis, or the Atlantic brief squid, is a small species of squid in the Loliginidae family. It is found in shallow parts of the western Atlantic Ocean.

Doryteuthis is a genus of squid from the waters of the western Atlantic and eastern Pacific off the coast of the Americas species are the common inshore squids of American waters. Some species are important quarry species for fisheries.

Slosarczykovia is a monotypic genus of squid, its sole representative being Slosarczykovia circumantarctica. Slosarczykovia is placed in the family Brachioteuthidae.

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.

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 Angolan flying squid is a species of squid from the subfamily Todarodinae, part of the familyOmmastrephidae. Due to taxonomic confusion with the Antarctic flying squid the exact limits of its distribution are uncertain but it is thought to be restricted to waters off Southern Africa.

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 circumglobar distribution in the seas around the lower latitudes of the Southern Oceans.

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.

Doryteuthis gahi, also known as the Patagonian squid and locally as calamar, is a small-sized squid belonging to the family Loliginidae. It occurs in coastal waters in the southeastern Pacific Ocean and the southwestern Atlantic Ocean where it is caught and eaten for food.

Uroteuthis noctiluca, commonly known as the luminous bay squid, is a species of squid native to shallow water on the eastern coast of Australia. It uses a pair of luminous organs to camouflage itself from predators at night.

References

1 2 Julian Finn (2016). "Doryteuthis (Doryteuthis) pleii (Blainville, 1823)". World Register of Marine Species. Flanders Marine Institute. Retrieved 23 February 2018.

Vecchione, M., E. Shea, S. Bussarawit, F. Anderson, D. Alexeyev, C.-C. Lu, T. Okutani, M. Roeleveld, C. Chotiyaputta, C. Roper, E. Jorgensen & N. Sukramongkol. (2005). "Systematics of Indo-West Pacific loliginids" (PDF). Phuket Marine Biological Center Research Bulletin66: 23–26.

External links

"CephBase: Doryteuthis plei". Archived from the original on 2005.

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[WoRMS-1] 1 2 Julian Finn (2016). "Doryteuthis (Doryteuthis) pleii (Blainville, 1823)". World Register of Marine Species. Flanders Marine Institute. Retrieved 23 February 2018.

Taxon identifiers
Loligo plei	Wikidata: Q3201277 Wikispecies: Doryteuthis pleii GBIF: 2290394 IRMNG: 10241639 ITIS: 82373
Doryteuthis plei	Wikidata: Q47464464 EoL: 448891 iNaturalist: 201529 NCBI: 1051068 WoRMS: 574543