The longfin inshore squid (''Doryteuthis pealeii'') is a species of

squid A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ...

of the family

Loliginidae Loliginidae, commonly known as pencil squids, is an aquatic family of squid classified in the order Myopsida. Taxonomy The family Loliginidae was formerly classified in the order Teuthida. Taxonomic list The classification below (includi ...

Description

This species of squid is often seen with a reddish hue, but like many types of squid can manipulate its color, varying from a deep red to a soft pink. The

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

mantle length of some males can reach up to 50 cm, although most squid commercially harvested are smaller than 30 cm long. This species exhibits

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

, with most males growing faster and reaching larger sizes than females. Loligo pealeii

Distribution

The longfin inshore squid is found in the

North Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for ...

, schooling in

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an islan ...

and

slope In mathematics, the slope or gradient of a Line (mathematics), line is a number that describes the direction (geometry), direction of the line on a plane (geometry), plane. Often denoted by the letter ''m'', slope is calculated as the ratio of t ...

waters from

Newfoundland Newfoundland and Labrador is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region of Labrador, having a total size of . As of 2025 the population ...

to the

Gulf of Venezuela The Gulf of Venezuela is a gulf of the Caribbean Sea bounded by the Venezuelan states of Zulia and Falcón and by La Guajira Department, Colombia. The western side is formed by the Guajira Peninsula. A strait connects it with Maracaibo Lake to ...

. It is commercially exploited, especially in the range from the Southern Georges Bank to

Cape Hatteras Cape Hatteras is a cape located at a pronounced bend in Hatteras Island, one of the barrier islands of North Carolina. As a temperate barrier island, the landscape has been shaped by wind, waves, and storms. There are long stretches of beach ...

. The population makes seasonal migrations that appear to be related to bottom water temperatures; they move offshore during late autumn to overwinter along the edge of the continental shelf and return inshore during the spring and early summer (MAFMC 1998).

Diet

"The diet of the longfin inshore squid changes with size; small immature individuals feed on planktonic organisms while larger individuals feed on crustaceans and small fish. Studies have shown that juveniles feed on euphausiids and arrow worms, while older individuals feed mostly on small crabs, but also on polychaetes and shrimp. Adults feed on fish (clupeids, myctophids) and squid larvae/juveniles, and those larger than 16 cm feed on fish and squid. Fish species preyed on by longfin inshore squid include silver hake, mackerel, herring, menhaden, sand lance, bay anchovy, weakfish, and silversides. Maurer and Bowman (1985) discovered a difference in inshore/offshore diet: in offshore waters in the spring, the diet is composed of crustaceans (mainly euphausiids) and fish; in inshore waters in the fall, the diet is composed almost exclusively of fish; and in offshore waters in the fall, the diet is composed of fish and squid. Cannibalism is observed in individuals larger than 5 cm."NOAA Longfin Inshore Squid, ''Loligo pealeii'', Life History and Habitat Characteristics
retrieved: Dec. 26, 2012

Predators

Many pelagic and demersal fish species, as well as marine mammals and diving birds, prey upon juvenile and adult longfin inshore squid. Marine mammal predators include longfin pilot whales and

common dolphin The common dolphin (''Delphinus delphis'') is the most abundant cetacean in the world, with a global population of about six million. Despite this fact and its vernacular name, the common dolphin is not thought of as the archetypal dolphin, wit ...

s. Fish predators include striped bass, bluefish, sea bass, mackerel, cod, haddock, pollock, silver hake, red hake, sea raven, spiny dogfish, angel shark, goosefish, dogfish,

mako shark ''Isurus'' (meaning "equal tail") is a genus of mackerel sharks in the family Lamnidae, commonly known as the mako sharks. They are largely pelagic, and are fast, predatory fish capable of swimming at speeds of up to . Fossil history and evolu ...

, blue marlin and flounder. These squid do have ways of evading predators too. They have a very complex way of swimming called jet propulsion. The fin stroke plus the propulsion creates a unique way of swimming in the ocean. This can help squid get away from predators more efficiently.

Reproduction

The longfin inshore squid spawns year-round and lives for less than one year. "Eggs are demersal. Enclosed in a gelatinous capsule containing up to 200 eggs. Each female lays 20-30 capsules. Fecundity ranges from 950–15,900 eggs per female. Laid in masses made up of hundreds of egg capsules from different females." Individuals hatched in summer generally grow more rapidly than those hatched in winter due to the warmer temperature of the water. The lifespan of a typical specimen is normally less than one year.

Research

This species is a

model organism A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. Mo ...

neuroscience Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions, and its disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, ...

and it was used by

Andrew Huxley Sir Andrew Fielding Huxley (22 November 191730 May 2012) was an English physiologist and biophysicist. He was born into the prominent Huxley family. After leaving Westminster School in central London, he went to Trinity College, Cambridge, ...

and

Alan Hodgkin Sir Alan Lloyd Hodgkin (5 February 1914 – 20 December 1998) was an English physiology, physiologist and biophysics, biophysicist who shared the 1963 Nobel Prize in Physiology or Medicine with Andrew Huxley and John Eccles (neurophysiologist) ...

in their studies on

axon An axon (from Greek ἄξων ''áxōn'', axis) or nerve fiber (or nerve fibre: see American and British English spelling differences#-re, -er, spelling differences) is a long, slender cellular extensions, projection of a nerve cell, or neuron, ...

s. Its axon is the largest axon known to science. They are also used for research on replicating their camouflage abilities due to the

chromatophore Chromatophores are cells that produce color, of which many types are pigment-containing cells, or groups of cells, found in a wide range of animals including amphibians, fish, reptiles, crustaceans and cephalopod A cephalopod is any member o ...

s in their skin, which reflect a different color depending on the angle at which the light is hitting them. A dead longfin can show a colourful display with its chromatophores by connecting its axons to a music player.Gage, Greg.
Insane in the ChromatophoresYoutube videoVimeo video
''Backyard Brains'', 23 August 2012. Retrieved: 2 September 2012.MBL Scientists Discover Nerves Control Iridescence in Squid’s Remarkable “Electric Skin”
''

Marine Biological Laboratory The Marine Biological Laboratory (MBL) is an international center for research and education in biological and environmental science. Founded in Woods Hole, Massachusetts, in 1888, the MBL is a private, nonprofit institution that was independent ...

'', 24 August 2012. Retrieved: 2 September 2012.Kenney, Diane.
Insanely Popular: MBL Squid Research/Rap Video Goes Viral
''

'', 31 August 2012. Retrieved: 2 September 2012.

References

External links

{{Taxonbar, from=Q2934323 Doryteuthis Cephalopods described in 1821 hu:Észak-amerikai kalmár