Humboldt Squid
Encyclopedia
The Humboldt squid also known as jumbo squid, jumbo flying squid, pota or diablo rojo (Spanish
for 'Red Devil'), is a large, predatory squid
found in the waters of the Humboldt Current
in the Eastern Pacific Ocean
. They are most commonly found at depths of 200 to, from Tierra del Fuego
to California
. Recent findings suggest the range of this species is spreading north into the waters of Oregon
, Washington, British Columbia
, and Alaska
. Though they usually prefer deep water, between 1,000 and 1,500 squid washed up on the Long Beach Peninsula
in southwest Washington in the fall of 2004. They have also ventured into Puget Sound
.
s of up to 1,200 individuals. They swim at speeds of up to 24 kilometres per hour (15 mph (12.3 kn)) propelled by water ejected through a hyponome
(siphon) and by two triangular fins. Their tentacle
s bear suckers lined with sharp teeth with which they grasp prey and drag it towards a large, sharp beak.
Although Humboldt squid have a reputation of being aggressive, there is some disagreement on this subject. Recent research suggests that Humboldt squid are only aggressive while feeding. At other times, they are quite passive. Their behavior while feeding often extends to cannibalism and they have been seen to readily attack injured or vulnerable squid of their own shoal. This behavior may account for a large proportion of their rapid growth. Some scientists claim the only reports of aggression towards humans have occurred when reflective diving gear or flashing lights have been present as a provocation. Roger Uzun, a veteran scuba diver and amateur underwater videographer who swam with a swarm of the animals for about 20 minutes, said they seemed to be more curious than aggressive. In circumstances where these animals are not feeding or being hunted, they exhibit curious and intelligent behavior
.
Electronic tagging has shown that Humboldt squid undergo diel vertical migration
s which bring them closer to the surface from dusk to dawn. Humboldt squid are thought to have a lifespan of only about one year, although larger individuals may survive up to two years. They may grow to 1.75 metres (5.7 ft) in mantle
length (ML) and weigh up to 50 kilograms (110.2 lb). They can rapidly change their skin color from deep purplish red to white using chromatophore
s (specialized skin cells) in what some researchers believe is a complex communication system. Experts have also stated that the squid hunt for their prey of small fish and krill
in a cooperative fashion, which would be the first observation of such behavior in invertebrates. Humboldt squid are known to hunt near the surface at night, taking advantage of the dark to use their keen vision to feed on more plentiful prey.
north to California
. It gets its name from the Humboldt Current
in which it lives off the coast of South America
. Recently, the squid have been appearing farther north, as far as Alaska
.
Generally, the tube (or body) constitutes about 40% of the animal's mass, the fin (or wing) about 12%, the tentacles about 14%, the outer skin about 3%, the head (including eyes and beak) about 5%, with the balance (26%) made up of the inner organs.
They often approach prey quickly with all ten appendages extended forward in a cone-like shape. Upon reaching striking distance, they will open their eight swimming and grasping arms, and extend two long tentacles covered in sharp 'teeth,' grabbing their prey and pulling it back towards a parrot-like beak, which can easily cause dramatic lacerations to human flesh. The whole process takes place in seconds.
Recent footage of shoals of these animals demonstrates a tendency to meet unfamiliar objects aggressively. Having risen to depths of 130 – below the surface to feed (up from their typical 700 metre (2,300 ft) diving depth, beyond the range of human diving), they have attacked deep-sea cameras and rendered them inoperable. Reports of recreational scuba divers
being attacked by Humboldt squid have been confirmed. One particular diver, Scott Cassell, who has spent much of his career videotaping this species, has developed body armor to protect against attacks. Each of the squid's suckers is ringed with sharp teeth, and the beak can tear flesh, although it is believed that they lack the jaw strength to crack heavy bone.
, crustacean
s, cephalopod
s, and copepod
s. The squid uses its barbed tentacle suckers to grab its prey and slices and tears the victim's flesh with its beak and radula
. The Humboldt squid is also known to quickly devour larger prey when hunting in groups. Although claims of cooperative hunting have been made for Dosidicus gigas, this behavior is unconfirmed. Until further study reveals otherwise, most researchers believe that group attacks by cephalopods on large prey are the result of many individuals attacking simultaneously but without any coordination.
Scientists suspect that the recent expansion of the squid's range north along the west coast of the US is the result of some combination of overfishing of longer-lived apex predators and higher temperatures.
Fisherman catch squid at night. Lights from the fishing boats reflect brightly on the plankton
, which lure the squid to the surface to feed. Since the 1990s, the most important areas for landings of Humboldt squid are Mexico
and northern Peru
.
Humboldt squid are known for their speed in feasting on hooked fish, sharks, and squid, even from their own species and shoal. There are numerous accounts of the squid attacking fishermen and divers in the area. Their colouring and aggressive reputation has earned them the nickname diablos rojos (red devils) from fishermen off the coast of Mexico
as they flash red and white when struggling with the fishermen.
. Then, during the minor El Niño event of 2002, Humboldt squid returned to Monterey Bay in higher numbers and have been seen there year-round since then. Similar trends have been shown off the coasts of Washington, Oregon
, and even Alaska
, although there are no year-round Humboldt squid populations in these locations. It has been suggested that this change in migration is due to warming waters during El Niño events, but other factors, such as a decrease in upper trophic level
predators that would compete with Humboldt squid for food, could be impacting the migration shift as well.
found that by the end of this century ocean acidification
will lower the Humboldt squid's metabolic rate by 31% and activity levels by 45%. This will lead the squid to have to retreat to shallower waters where it can uptake oxygen at higher levels.
Spanish language
Spanish , also known as Castilian , is a Romance language in the Ibero-Romance group that evolved from several languages and dialects in central-northern Iberia around the 9th century and gradually spread with the expansion of the Kingdom of Castile into central and southern Iberia during the...
for 'Red Devil'), is a large, predatory squid
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
found in the waters of the Humboldt Current
Humboldt Current
The Humboldt Current , also known as the Peru Current, is a cold, low-salinity ocean current that flows north-westward along the west coast of South America from the southern tip of Chile to northern Peru. It is an eastern boundary current flowing in the direction of the equator, and can extend...
in the Eastern Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
. They are most commonly found at depths of 200 to, from Tierra del Fuego
Tierra del Fuego
Tierra del Fuego is an archipelago off the southernmost tip of the South American mainland, across the Strait of Magellan. The archipelago consists of a main island Isla Grande de Tierra del Fuego divided between Chile and Argentina with an area of , and a group of smaller islands including Cape...
to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. Recent findings suggest the range of this species is spreading north into the waters of Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, Washington, British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, and Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
. Though they usually prefer deep water, between 1,000 and 1,500 squid washed up on the Long Beach Peninsula
Long Beach Peninsula
The Long Beach Peninsula is an arm of land in western Washington state. It is bounded on the west by the Pacific Ocean, the south by the Columbia River, and the east by Willapa Bay...
in southwest Washington in the fall of 2004. They have also ventured into Puget Sound
Puget Sound
Puget Sound is a sound in the U.S. state of Washington. It is a complex estuarine system of interconnected marine waterways and basins, with one major and one minor connection to the Strait of Juan de Fuca and the Pacific Ocean — Admiralty Inlet being the major connection and...
.
Behavior and general characteristics
Humboldt squid are carnivorous marine invertebrates that move in shoalShoaling and schooling
In biology, any group of fish that stay together for social reasons are said to be shoaling , and if, in addition, the group is swimming in the same direction in a coordinated manner, they are said to be schooling . In common usage, the terms are sometimes used rather loosely...
s of up to 1,200 individuals. They swim at speeds of up to 24 kilometres per hour (15 mph (12.3 kn)) propelled by water ejected through a hyponome
Hyponome
A siphon is an anatomical structure which is part of the body of aquatic molluscs in three classes: Gastropoda, Bivalvia and Cephalopoda. In other words, a siphon is found in some saltwater and freshwater snails, in some clams, and in octopus, squid and relatives.Siphons in molluscs are tube-like...
(siphon) and by two triangular fins. Their tentacle
Tentacle
A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...
s bear suckers lined with sharp teeth with which they grasp prey and drag it towards a large, sharp beak.
Although Humboldt squid have a reputation of being aggressive, there is some disagreement on this subject. Recent research suggests that Humboldt squid are only aggressive while feeding. At other times, they are quite passive. Their behavior while feeding often extends to cannibalism and they have been seen to readily attack injured or vulnerable squid of their own shoal. This behavior may account for a large proportion of their rapid growth. Some scientists claim the only reports of aggression towards humans have occurred when reflective diving gear or flashing lights have been present as a provocation. Roger Uzun, a veteran scuba diver and amateur underwater videographer who swam with a swarm of the animals for about 20 minutes, said they seemed to be more curious than aggressive. In circumstances where these animals are not feeding or being hunted, they exhibit curious and intelligent behavior
Cephalopod intelligence
Cephalopod intelligence has an important comparative aspect in the understanding of intelligence because it relies on a nervous system fundamentally different from that of vertebrates...
.
Electronic tagging has shown that Humboldt squid undergo diel vertical migration
Diel vertical migration
Diel vertical migration, also known as diurnal vertical migration, is a pattern of movement that some organisms living in the ocean and in lakes undertake each day. Usually organisms move up to the epipelagic zone at night and return to the mesopelagic zone of the oceans or to the hypolimnion zone...
s which bring them closer to the surface from dusk to dawn. Humboldt squid are thought to have a lifespan of only about one year, although larger individuals may survive up to two years. They may grow to 1.75 metres (5.7 ft) in mantle
Mantle (mollusc)
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.In many, but by no means all, species of molluscs, the epidermis of the mantle secretes...
length (ML) and weigh up to 50 kilograms (110.2 lb). They can rapidly change their skin color from deep purplish red to white using chromatophore
Chromatophore
Chromatophores are pigment-containing and light-reflecting cells found in amphibians, fish, reptiles, crustaceans, and cephalopods. They are largely responsible for generating skin and eye colour in cold-blooded animals and are generated in the neural crest during embryonic development...
s (specialized skin cells) in what some researchers believe is a complex communication system. Experts have also stated that the squid hunt for their prey of small fish and krill
Krill
Krill is the common name given to the order Euphausiacea of shrimp-like marine crustaceans. Also known as euphausiids, these small invertebrates are found in all oceans of the world...
in a cooperative fashion, which would be the first observation of such behavior in invertebrates. Humboldt squid are known to hunt near the surface at night, taking advantage of the dark to use their keen vision to feed on more plentiful prey.
Distribution
The Humboldt squid lives at depths of 200 to 700 m (656.2 to 2,296.6 ft) in the eastern Pacific (Chile, Peru), ranging from Tierra del FuegoTierra del Fuego
Tierra del Fuego is an archipelago off the southernmost tip of the South American mainland, across the Strait of Magellan. The archipelago consists of a main island Isla Grande de Tierra del Fuego divided between Chile and Argentina with an area of , and a group of smaller islands including Cape...
north to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. It gets its name from the Humboldt Current
Humboldt Current
The Humboldt Current , also known as the Peru Current, is a cold, low-salinity ocean current that flows north-westward along the west coast of South America from the southern tip of Chile to northern Peru. It is an eastern boundary current flowing in the direction of the equator, and can extend...
in which it lives off the coast of South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. Recently, the squid have been appearing farther north, as far as Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
.
Body characteristics
They often approach prey quickly with all ten appendages extended forward in a cone-like shape. Upon reaching striking distance, they will open their eight swimming and grasping arms, and extend two long tentacles covered in sharp 'teeth,' grabbing their prey and pulling it back towards a parrot-like beak, which can easily cause dramatic lacerations to human flesh. The whole process takes place in seconds.
Recent footage of shoals of these animals demonstrates a tendency to meet unfamiliar objects aggressively. Having risen to depths of 130 – below the surface to feed (up from their typical 700 metre (2,300 ft) diving depth, beyond the range of human diving), they have attacked deep-sea cameras and rendered them inoperable. Reports of recreational scuba divers
Recreational diving
Recreational diving or sport diving is a type of diving that uses SCUBA equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels...
being attacked by Humboldt squid have been confirmed. One particular diver, Scott Cassell, who has spent much of his career videotaping this species, has developed body armor to protect against attacks. Each of the squid's suckers is ringed with sharp teeth, and the beak can tear flesh, although it is believed that they lack the jaw strength to crack heavy bone.
Ecology
The Humboldt squid feeds primarily on small fishFish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, cephalopod
Cephalopod
A cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...
s, and copepod
Copepod
Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat. Some species are planktonic , some are benthic , and some continental species may live in limno-terrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests,...
s. The squid uses its barbed tentacle suckers to grab its prey and slices and tears the victim's flesh with its beak and radula
Radula
The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...
. The Humboldt squid is also known to quickly devour larger prey when hunting in groups. Although claims of cooperative hunting have been made for Dosidicus gigas, this behavior is unconfirmed. Until further study reveals otherwise, most researchers believe that group attacks by cephalopods on large prey are the result of many individuals attacking simultaneously but without any coordination.
Scientists suspect that the recent expansion of the squid's range north along the west coast of the US is the result of some combination of overfishing of longer-lived apex predators and higher temperatures.
Fishing
Commercially, this species has been caught to serve the European community market (mainly Spain, Italy, France and Ireland), Russia, China, Japan, South East Asian and increasingly North and South American markets.Fisherman catch squid at night. Lights from the fishing boats reflect brightly on the plankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
, which lure the squid to the surface to feed. Since the 1990s, the most important areas for landings of Humboldt squid are Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
and northern Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
.
Humboldt squid are known for their speed in feasting on hooked fish, sharks, and squid, even from their own species and shoal. There are numerous accounts of the squid attacking fishermen and divers in the area. Their colouring and aggressive reputation has earned them the nickname diablos rojos (red devils) from fishermen off the coast of Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
as they flash red and white when struggling with the fishermen.
Humboldt squid and El Niño
Although Humboldt squid are generally found in the warm Pacific waters off of the Mexican coast, recent years have shown an increase in northern migration. The large 1997-98 El Niño event triggered the first sightings of Humboldt squid in Monterey BayMonterey Bay
Monterey Bay is a bay of the Pacific Ocean, along the central coast of California. The bay is south of San Francisco and San Jose, between the cities of Santa Cruz and Monterey....
. Then, during the minor El Niño event of 2002, Humboldt squid returned to Monterey Bay in higher numbers and have been seen there year-round since then. Similar trends have been shown off the coasts of Washington, Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, and even Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
, although there are no year-round Humboldt squid populations in these locations. It has been suggested that this change in migration is due to warming waters during El Niño events, but other factors, such as a decrease in upper trophic level
Trophic level
The trophic level of an organism is the position it occupies in a food chain. The word trophic derives from the Greek τροφή referring to food or feeding. A food chain represents a succession of organisms that eat another organism and are, in turn, eaten themselves. The number of steps an organism...
predators that would compete with Humboldt squid for food, could be impacting the migration shift as well.
Humboldt squid and ocean acidification
A study published in the Proceedings of the National Academy of SciencesProceedings of the National Academy of Sciences
The Proceedings of the National Academy of Sciences of the United States of America, usually referred to as PNAS, is the official journal of the United States National Academy of Sciences...
found that by the end of this century ocean acidification
Ocean acidification
Ocean acidification is the name given to the ongoing decrease in the pH and increase in acidity of the Earth's oceans, caused by the uptake of anthropogenic carbon dioxide from the atmosphere....
will lower the Humboldt squid's metabolic rate by 31% and activity levels by 45%. This will lead the squid to have to retreat to shallower waters where it can uptake oxygen at higher levels.