Humboldt squid Temporal range: | |
---|---|
A Humboldt squid swimming around ROV Tiburon, possibly attracted to its lights | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Cephalopoda |
Order: | Oegopsida |
Family: | Ommastrephidae |
Subfamily: | Ommastrephinae |
Genus: | Dosidicus Steenstrup, 1857 |
Species: | D. gigas |
Binomial name | |
Dosidicus gigas | |
Synonyms [3] | |
The Humboldt squid (Dosidicus gigas), also known as jumbo squid or jumbo flying squid (EN), and Pota in Peru or Jibia in Chile (ES), is a large, predatory squid living in the eastern Pacific Ocean. It is the only known species of the genus Dosidicus of the subfamily Ommastrephinae, family Ommastrephidae. [4]
Humboldt squid typically reach a mantle length of 1.5 m (4 ft 11 in), making the species the largest member of its family. They are the most important squid worldwide for commercial fisheries, with the catch predominantly landed in Chile, Peru and Mexico; however, a 2015 warming waters fishery collapse in the Gulf of California remains unrecovered. [5] [6] Like other members of the subfamily Ommastrephinae, they possess chromatophores which enable them to quickly change body coloration, known as 'metachrosis’ which is the rapid flash of their skin from red to white. They have a relatively short lifespan of just 1–2 years. They have a reputation for aggression toward humans, although this behavior may only occur during feeding times.
They are most commonly found at depths of 200 to 700 m (660 to 2,300 ft), from Tierra del Fuego to California. This species is spreading north into the waters of the Pacific Northwest, in Oregon, Washington, British Columbia, and Alaska.
The existence of this creature was first reported to the scientific world by the Chilean priest and polymath Juan Ignacio Molina in 1782, who named it Sepia tunicata, Sepia being the cuttlefish genus. The French naturalist Alcide d'Orbigny renamed it Loligo gigas in 1835. In Chile, Claude Gay, another French naturalist, obtained some specimens and sent them to the Muséum national d'Histoire naturelle in Paris, where it was determined that the species did not belong with Loligo either. In 1857 the Danish zoologist Japetus Steenstrup proposed the new genus Dosidicus to house the species. [7]
The German zoologist George Pfeffer synonymized D. eschrichtii with D. gigas in 1912. [7] [8]
The fossil species Dosidicus lomita is represented in statoliths from the Pliocene Lomita Marl of California, marking the earliest known occurrence of the genus. [9]
This species is most often known as jumbo squid in English, but has also been called jumbo flying squid or Humboldt squid, with the last name most popular in naturalist sources. [10] The name Humboldt refers to the Humboldt Current, off the southwestern coast of South America, where it was first collected. [11]
A general name for this species in Spanish in Latin America is calamar gigante. [12] [13] Local names for it are jibia in Chile [14] or pota in Peru. [15] They notably rapidly flash red and white when captured, earning them the nickname diablo rojo (meaning 'red devil') among local fishermen in Baja California, Mexico. [16]
The Humboldt squid is the largest of the Ommastrephid squids, as some individuals may grow to 1.5 m (5 ft) in mantle length [17] [18] and weigh up to 50 kg (110 lb). [8] They appear to be sexually dimorphic: on average the females mature at larger sizes than the males. [19] Generally, the mantle (or body) constitutes about 56–62% of the animal's mass (which includes the fins or wings), the arms and tentacles about 11–15%, the head (including eyes and beak) about 10–13%, the outer skin (cuticle) 2.5–5.0%, the liver 4.2–5.6%, with the rest made up of the other inner organs. The gonads consist of 1.5–15.0% of the total mass. The gladius (the single inner 'bone') is 0.7–1.0%. Precise ratios depend on the age, sex and sizes of the individual squid. [20]
They are propelled by water ejected through a hyponome (siphon) and by two triangular fins. [21] The Humboldt's two tentacles are elastic and can lash out with remarkable speed to grab hold of prey, holding it fast with the help of a wealth of suckers on each tentacle; these then retract and the prey is drawn toward a large, razor-sharp beak. [21]
Humboldt squid are carnivorous marine invertebrates that move in shoals of up to 1,200 individuals. They swim at speeds up to 24 km/h (15 mph; 13 kn). [22]
Electronic tagging has shown Humboldt squid undergo diel vertical migrations, which bring them closer to the surface from dusk to dawn. [23] Humboldt squid are thought to have a lifespan of about a year, although larger individuals may survive up to 2 years. [8]
Crittercams attached to two or three Humboldt squid revealed the species has two modes of color-generating (chromogenic) behavior:
Although these two chromogenic modes are not known in other squid species, other species do have functionally similar behaviors. [24] [25]
The Humboldt squid lives at depths of 200 to 700 m (660 to 2,300 ft) in the eastern Pacific (Notably in Chile and Peru), ranging from Tierra del Fuego north to California. Recently, the squid have been appearing farther north, as far as British Columbia. [11] They have also ventured into Puget Sound. [26]
Though they usually prefer deep water, between 1,000 and 1,500 squid washed up on the Long Beach Peninsula in southwest Washington in late 2004 [27] and red algae were a speculated cause for the late 2012 beaching of an unspecified number of juvenile squid (average length 50 cm [1.5 ft]) at Monterey Bay over a 2-month period. [28]
Humboldt squid are generally found in the warm Pacific waters off the Mexican coast; studies published in the early 2000s indicated an increase in northern migration. The large 1997–1998 El Niño event triggered the first sightings of Humboldt squid in Monterey Bay. Then, during the minor El Niño event of 2002, they 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 no year-round Humboldt squid populations are in these locations. This change in migration is suggested to be due to warming waters during El Niño events, but other factors, such as a decrease in upper trophic level predators that would compete with the squid for food, could be impacting the migration shift, as well. [11] [29]
A 2017 Chinese study found that D. gigas is affected by El Niño events in the waters off Peru. The squid populations cluster into groups less, and are thus more dispersed, during El Niño events. Additionally, during warm El Niño conditions and high water temperature the waters off Peru were less favourable for D. gigas. [30]
The Humboldt squid's diet consists mainly of small fish (lanternfish, in particular), crustaceans, cephalopods, and copepods. [31] The squid uses its barbed tentacle suckers to grab its prey and slices and tears the victim's flesh with its beak and radula. They often approach prey quickly with all 10 appendages extended forward in a cone-like shape. Upon reaching striking distance, they open their eight swimming and grasping arms, and extend two long tentacles covered in sharp hooks, grabbing their prey and pulling it back toward a parrot-like beak, which can easily cause serious lacerations to human flesh. These two longer tentacles can reach full length, grab prey, and retract so fast that almost the entire event happens in one frame of a normal-speed video camera. Each of the squid's suckers is ringed with sharp teeth, and the beak can tear flesh, although they are believed to lack the jaw strength to crack heavy bone. [21]
Their behavior while feeding often includes cannibalism and they have been seen to readily attack injured or vulnerable squid in their shoal. A quarter of squid stomachs analyzed contained remains of other squid. [32] This behavior may account for a large proportion of their rapid growth. [21] [33] An investigation of the stomach contents of over 2,000 squid caught outside of the Exclusive Economic Zone off the coasts of Chile found that cannibalism was likely the most important source of food. Over half had the beaks of D. gigas in their stomachs, and D. gigas was the most common prey item. The researchers do note, however, that squid jigged in the light field around the survey vessel showed much more cannibalism. [19]
Until recently, claims of cooperative or coordinated hunting in D. gigas were considered unconfirmed and without scientific merit. [34] However, research conducted between 2007 and 2011 indicates this species does engage in cooperative hunting. [35]
The squid are known for their speed at eating; they feast on hooked fish, stripping them to the bone before fishermen can reel them in. [21]
Females lay gelatinous egg masses that are almost entirely transparent and float freely in the water column. The size of the egg mass correlates with the size of the female that laid it; large females can lay egg masses up to 3–4 m in diameter, [36] while smaller females lay egg masses about one meter in diameter. Records of egg masses are extremely sparse because they are rarely encountered by humans, but from the few masses found to date, the egg masses seem to contain anywhere from 5,000 to 4.1 million eggs, depending on size. [37]
Commercially, this species has been caught to serve the European market (mainly Spain, Italy, France, and Ireland), Russia, China, Japan, Southeast Asia, and increasingly North and South American markets.[ citation needed ]
It is the most popular squid in the world, as of 2019 a third of all squid hunted is this species. [39]
The method used by both artisanal fishermen as well as more industrial operations to catch the squid is known as jigging. [13] [19] Squid jigging is a relatively novel method of fishing in the Americas. [40] It is done by handlining by artisanal fishermen, or by using mechanical jiggers. [13] [41] Jigging involves constantly jerking the line up and down to simulate prey; a reel with an elliptical or oval-shaped hub helps with this. [41] [42] Squid jigging is done at night, using bright overhead lights from the fishing boats which reflect brightly off the jigs and plankton in the seawater, luring the squid toward the surface to feed. The seem to prefer striking at the jigs from adjacent shadowed areas, especially the shade under the hull of the boat. [40] [41] Often as many as 8 to 12 jigs are on snoods on one handline, and many more are used on automated squid jigging systems. [41] The lines are hung anywhere from 10 to 100m in depth, depending on the power of the lamps used. [41] [42]
The jigs are called poteras in Spanish. Different types of jigs are suitable for either handlining or for mechanical jigging for jumbo squid. They are made from bakelite and/or stainless steel, and measure 75 to 480mm in length. Jigs can have a single axis, or one to three 'arms' (ejes) which wave around when the jig is jerked, [13] and a series of crowns (coronas) of bristle-like wire-hooks, the hooks lacking barbs, making up the tail. [13] [41] The body of the jigs is usually phosphorescent, [13] but glow-in-the-dark lures may be attached to them. [42] Jigs are extremely selective, not only can one type of jig attract only squid, often the jigs can select for a single species of squid, and even specific sizes of that species. The more arms and crowns, the more hooks, the higher the chances of snagging and actually reeling in the squid. [13]
Since the 1990s, the most important areas for landings of Humboldt squid are Chile, Mexico, and Peru (122–297, 53–66, and 291–435 thousand tonnes, respectively, in the period 2005–2007). [19]
Based on 2009 national fisheries data, in Mexico this species represents 95% of the total recorded catch of squid. 88% of this is caught off the coasts of Sonora and Baja California Sur. [12]
Because the flesh of the animals is saturated with ammonium chloride (salmiak), which keeps them neutrally buoyant in seawater, the animal tastes unpleasantly salty, sour, and bitter when fresh. To make the squid more palatable for the frozen squid market, freshly caught Humboldt squid are commercially processed by first mechanically tenderizing them, dropping them in icy water with 1% mixture of lactic and citric acid for three hours, then washed, then soaked in another vat with a 6% brine solution for three hours. There is also a method for home cooks to neutralize the unpleasant taste. [14]
Compared to other types of seafood, Humboldt squid is inexpensive in Pacific South America, retailing around US$0.30/kg in Peru, and about US$2.00/kg in Chile, in the early 2010s. [14] [15]
In Chile the squid is eaten in chupes and paila marina . [14] In Peru, the practice of making ceviche from cheap squid began in the poorer parts of Lima when the meat became available in the 1990s, and has since spread to Cuzco. It is sold on the street in food carts, as well as cevicherias, restaurants dedicated to this cuisine. [15] In the United States it is made into 'squid steaks'.
Numerous accounts have the squid attacking fishermen and divers. [43] Their coloring and aggressive reputation have earned them the nickname diablos rojos (red devils) from fishermen off the coast of Mexico, as they flash red and white when struggling on a line. [16]
Although Humboldt squid have a reputation of being aggressive toward humans, some disagreement exists on this subject. Research suggests these squid are aggressive only while feeding; at other times, they are quite passive. [32] Some scientists claim the only reports of aggression toward 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. [44] In circumstances where these animals are not feeding or being hunted, they exhibit curious and intelligent behavior. [45]
Recent footage of shoals of these animals demonstrates a tendency to meet unfamiliar objects aggressively. Having risen to depths of 130–200 m (430–660 ft) below the surface to feed (up from their typical 700 m (2,300 ft) diving depth, beyond the range of human diving), they have attacked deep-sea cameras and rendered them inoperable. Humboldt squid have also been observed engaging in swarm behavior when met by the lights of submersibles, suggesting that they may follow or are attracted to light. Reports of recreational scuba divers being attacked by Humboldt squid have been confirmed. [46] [47]
In Chile, at the end of the 50s and early 60s, electrophysiological and neurophysiological studies were carried out by the Montemar Institute of Marine Biology, [48] [49] [50] [51] [52] in Valparaiso, Chile. The remarkable size of the squid giant axon and squid giant synapse possessed by the Humboldt squid made it ideal for manipulative work in the laboratory. [48] This research was chronicled in the documentary Montemar y Los Laberintos de la Memoria[Montemar and The Labyrinths of Memory]. 2016.
A 2008 study predicted that ocean acidification will lower the Humboldt squid's metabolic rate by 31% and activity levels by 45% by the end of the 21st century. It also predicted that the squid wouldn't be able to spend as much of the day in deeper and colder waters, as a larger proportion of the ocean would fall into the oxygen minimum zone. [53]
A more recent study, however, provided empirical and theoretical evidence that the squid metabolism was unaffected by ocean acidification. [54]
The Humboldt squid was featured in the final episode of the 2009 BBC's Last Chance to See with Stephen Fry and Mark Carwardine. The episode was about blue whales, but the presenters interviewed fishermen who talked about the exploding diablo rojo population in the Sea of Cortez and human attacks, and showed a squid trying to take a bite of a protectively clad forearm.
In 2016 the squid featured in various television shows. Man Eating Super Squid: A Monster Invasion on the National Geographic Wild channel explored various attacks by Humboldt squid in Mexico. In the show, the squid is referred to as a real-life kraken and as "a global threat". [55] The second show was River Monsters: Devil of the Deep, where show host Jeremy Wade talks to fishermen allegedly attacked by the squid in the Sea of Cortez, and then catches the animals off the coast of Peru. [56] In the British Fishing Impossible , mail-clad divers plan to capture a Humboldt squid by hand in the Pacific Ocean, but are prevented from doing so due to bad weather. [57] In BBC Earth's Blue Planet II the squid's cannibalistic pack hunting was captured on film for the first time. [58]
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.
A cephalopod is any member of the molluscan class Cephalopoda such as a squid, octopus, cuttlefish, or nautilus. 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. Fishers sometimes call cephalopods "inkfish", referring to their common ability to squirt ink. The study of cephalopods is a branch of malacology known as teuthology.
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. This makes it longer than the colossal squid at an estimated 9–10 m (30–33 ft), but substantially lighter, as the tentacles make up most of the length. 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.
The vampire squid is a small cephalopod found throughout temperate and tropical oceans in extreme deep sea conditions. The vampire squid uses its bioluminescent organs and its unique oxygen metabolism to thrive in the parts of the ocean with the lowest concentrations of oxygen. It has two long retractile filaments, located between the first two pairs of arms on its dorsal side, which distinguish it from both octopuses and squids, and places it in its own order, Vampyromorphida, although its closest relatives are octopods. As a phylogenetic relict, it is the only known surviving member of its order.
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, comprised around half of the world's cephalopod catch annually.
The Caribbean reef squid, commonly called the reef squid, is a species of small, torpedo-shaped squid with undulating fins that extend nearly the entire length of the body, approximately 20 cm in length. They are most commonly found in the Caribbean Sea in small schools. As part of the Cephalopod class of Molluscs, these organisms exhibit specific characteristics to help them in their environment, such as tentacles for movement and feeding and color pigments that reflect their behavioral conditions.
Cephalopods, which include squids and octopuses, vary enormously in size. The smallest are only about 1 centimetre (0.39 in) long and weigh less than 1 gram (0.035 oz) at maturity, while the giant squid can exceed 10 metres (33 ft) in length and the colossal squid weighs close to half a tonne (1,100 lb), making them the largest living invertebrates. Living species range in mass more than three-billion-fold, or across nine orders of magnitude, from the lightest hatchlings to the heaviest adults. Certain cephalopod species are also noted for having individual body parts of exceptional size.
Onychoteuthis banksii, the common clubhook squid, is a species of squid in the family Onychoteuthidae. It is the type species of the genus Onychoteuthis. This species was thought to have a worldwide distribution but with the revision of the genus Onychoteuthis in 2010, it is now accepted that Onychoteuthis banksii is restricted to the central and northern Atlantic and the Gulf of Mexico while a recently described species, Onychoteuthis horstkottei, is found in the Pacific Ocean. The type locality is the Gulf of Guinea.
The common cuttlefish or European common cuttlefish is one of the largest and best-known cuttlefish species. They are a migratory species that spend the summer and spring inshore for spawning and then move to depths of 100–200 metres (330–660 ft) during autumn and winter. They grow to 49 centimetres (19 in) in mantle length and 4 kilograms (8.8 lb) in weight. Animals from subtropical seas are smaller and rarely exceed 30 centimetres (12 in) in mantle length.
William Frank Gilly is an American biologist specializing in the study of cephalopods. He works at Gilly Lab, Hopkins Marine Station, in Monterey County, as a professor of biology, at Stanford University and was involved with the television special The Future is Wild.
Gonatus onyx is in the class Cephalopoda and in the phylum Mollusca. It is also known as the clawed arm hook squid or the black-eyed squid. It got these names from the characteristic black eye and from its two arms with clawed hooks on the end that extend a bit further than the other arms. It is a squid in the family Gonatidae, found most commonly in the northern Pacific Ocean from Japan to California. They are one of the most abundant cephalopods off the coast of California, mostly found at deeper depths, rising during the day most likely to feed.
The colossal squid is the world’s largest squid species and the world’s largest mollusc. It belongs to the Cranchiidae family, that of the cockatoo squids or glass squids. 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.
Ommastrephinae is a subfamily of squids under the family Ommastrephidae.
Cephalopod attacks on humans have been reported since ancient times. A significant portion of these attacks are questionable or unverifiable tabloid stories. Cephalopods are members of the class Cephalopoda, which includes all squid, octopuses, cuttlefish, and nautiluses. Some members of the group are capable of causing injury or death to humans.
All extant cephalopods have a two-part beak, or rostrum, situated in the buccal mass and surrounded by the muscular head appendages. The dorsal (upper) mandible fits into the ventral (lower) mandible and together they function in a scissor-like fashion. The beak may also be referred to as the mandibles or jaws. These beaks are different from bird beaks because they crush bone while most bird beaks do not.
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.
The purpleback flying squid or purpleback squid is a species of cephalopod in the family Ommastrephidae, occurring in the Indo-Pacific. It is considered one of the most abundant large squids.
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 Loligo, the Patagonian longfin squid and Patagonian squid, 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.