| Sthenoteuthis oualaniensis | |
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Order: | Oegopsida |
| Family: | Ommastrephidae |
| Genus: | Sthenoteuthis |
| Species: | S. oualaniensis |
| Binomial name | |
| Sthenoteuthis oualaniensis | |
| Synonyms [2] | |
The purpleback flying squid or purpleback squid (Sthenoteuthis oualaniensis) is a species of cephalopod in the family Ommastrephidae, occurring in the Indo-Pacific. It is considered one of the most abundant large squids.
S. oualaniensis are sexually dimorphic where the females tend to grow larger than the males in most cases. [3] Dimorphism differentiation occurs in the sucker ring dentition in which different sizes occur which suggests that a feeding spectrum occurs among male and female individuals. [3]
The species has a complex population structure, comprising three major and two minor forms with different morphology, anatomy, geographical distribution, and period of spawning. [3] [4] [5] These forms include a giant form, a medium form with a double lateral axis on the gladius, a medium form with a single lateral axis on the gladius, a dwarf form, and a smaller earlier maturing form. [3] [6] The medium form is characterized by a dorsal photophore patch and fused mantle locking apparatus, it is the most common or “typical” form, and has the largest geographical distribution divide with a deeper vertical distribution when compared to the dwarf form. [3] [4] [7] The dorsal mantle length (ML) of sexually mature adult males and females is 120 – 150 mm and 190 – 250 mm respectively. [7] The smaller forms include a dwarf from an early maturing form, these two forms can be classified under the same category due to significant similarities as there is some disagreement in the literature. [3] [4] [7] The smaller forms have no dorsal photophore patches and tend to reside in the equatorial waters (10 – 15 º N and S) of the Indonesian-Pacific Oceans, in which it spends the majority of its life in the upper mixed layers. [3] [4] [7] The ML in the adult's males and females is 90 – 100 mm and 90 – 120 mm respectively. [7] The giant forms are categorized by a dorsal photophore with a single lateral axis on the gladius and fused locking apparatus its distribution includes the Red Sea, the Arabian Sea and the Gulf of Aden northward of approximate 12 º N, to our knowledge a few mature adult females were recorded in the equatorial region of having an ML of 725 and 820 mm, whereas in the Arabian Sea an adult female had an ML of 300 – 500 mm. [4] [6] [7] The different size forms can be explained by phenotypic plasticity due to environmental conditions. [8]
The species occurs in a diverse range of environments in the tropical and subtropical Indo-Pacific, at depths from the surface to more than 600 m (1,969 ft) deep. [9] [6] [7] Total species biomass has been estimated at between 8 – 11 million tonnes; the Arabian Sea from November to January is thought to have one of the highest concentrations (12 to 42 t km−2) due to population dynamics. [3]
Purpleback flying squids, which are thought to be both predators and prey, are considered both because throughout their life they are constantly changing, with continuous body-size increases allowing them to fulfill different trophic levels on the taxonomic and ecological spectrum in consideration of their food organisms, enemies and parasites. [6] They feed utilizing a beak, which is a hard structure that contains composites of proteins and chitin fibres. [10] Beaks are an important morphological characteristic; they can be used to identify and classify a species as they are easy to see with the naked eye and do not break down in the stomachs of predators. [10] This feeding organ tears up and bites food, and throughout the squid's life, the characteristics of a beak can change as a result of ontogenetic states. [10] The wing of the beak undergoes pigmentation that is related to the stiffness or hardness of the beak; the more tanned regions are harder than the untanned regions, and this pigmentation is directly linked with growth and changes in the diet. [10]
Purpleback flying squids are highly active predators that can move through the water at high speeds, easily manoeuvre and respond swiftly to changes in their environment. [6] When under distress from external factors such as predation, they can reach a high speed and glide above the surface over ten meters; the cruising speed of an adult squid is between 3 and 10 km per hour, whereas their burst speed can reach 35 km per hour. Burst speed can be important for sudden changes in movement and escape behaviour. [6] They can gather into shoals ranging in size from two to 800 individuals, and in some cases in which geographical distributions overlap, they can travel within similar-sized schools of Dosidicus gigas and Ommastrephes bartramii. [9]
The diet of purpleback flying squids depends on their mantle length; young squids or paralarva tend to feed predominately on mesozooplankton and mesozooplankton, which include copepods, amphipods and many others. [6] Juveniles or post-paralarvae can feed on mesoplanktonic and macroplanktonic invertebrates, which mainly include copepods, euphausiids, amphipods and chaetognaths, as well as micronekton fishes (mainly myctophids) and squids, as their mantle length cane range between 10 and 80 mm. [6] As they grow larger, their preference shifts toward larger fishes and squids and even other purpleback flying squids, as cannibalism is fairly common in this species. [6]
Purpleback flying squids are predated upon by many species throughout their life as they increase in size. [6] Paralarvae and juveniles are usually eaten by larger animals that include chaetognaths, jellyfishes, small squids, planktivorous and small carnivores teleosts. [6] Juveniles that have a mantle lengths of 3 to 12 mm are preyed on by large Humboldt squids Dosidicus gigas, dolphinfishes Coryphaena hippurus, C. equisetis, the snake mackerel Gempylus serpens, the lancet fish Alepisaurus ferox and many species of tuna. [6] Many species of sea birds also predate on juvenile and smaller squids in oceanic regional islands. [6] The predators of the medium- to large-sized purpleback squids include swordfishes Xiphias gladis, striped marlins Tetrapterus audax, many species of different sharks (for instance, the blue shark Prionace glauca), the dusky shark Carcharhinus obscurus, the oceanic whitetip shark Carcharhinus logimanus, the silky shark Carcharhinus falciformis, the smooth hammerhead shark Sphyrna zyganea, the sperm whale Physeter macrocephalus and the Galapagos fur seal Arctocephalus galapagoensis. [6]
Purpleback squids are thought to have a lifespan of up to one year, but the lifespan of much larger squids is unknown. [6] [11] The purpleback squid's spawning method is characteristic of the subfamily Ommastrephinae. [6] S. oualaniensis is a monocyclic r-strategist, and the potential fecundity is dependent on the form type of the squid, which can range from 0.3 to 22 million. [6]
The purpleback squid exhibits no premating rituals, as its overall mating system tends to be polygynous to polyandrous. [6] Mating occurs in the surface waters at night where the squids mate in the “male-parallel” or the “head-to-head” positions to increase the likelihood of successful mating. [6] The overall duration of mating is short, lasting up to two minutes. Successful copulations can produce up to 150 spermatangia, which are then attached to the buccal cone and the membrane of the females. [6] Specific to this species are year-round spawning periods that can last up to three months for female squids. [6] The peak season is also dependent on the form type of the squid. Spawning takes place near the epipelagic zone at night, while spawning occurs in intervals (up to 10 cycles) rather than in continuous time, and multiple batches can occur within one spawning period. [6]
After spawning is completed, the large, pelagic, gelatinous egg masses will float to the surface above the upper pycnocline layer./ The females will remain to feed and grow while the remaining oocytes are matured and the next spawning interval begins. [6] The duration of embryonic development is dependent on water temperature. [6] For example, if development occurs at a water temperature of 25 °C, it takes approximately three to six days. [6] The egg size can range from 0.75 to 0.9 mm, and the hatchling size has a mantle length of approximately 1.0 mm. [6]
Purpleback squids are among the fastest-growing squid species, as the daily increase of overall length in the dwarf and middle-sized forms is about 1.0 mm; for the giant form, it is about 3.8 mm. [6]
When embryonic development is complete, it is characterized by a paralarval stage that is unique to octopuses and squids. The paralarva is also known as the rhynchoteuthion stage, which is identified by the tentacles fusing to form a trunk-like proboscis with a few suckers on the distal tip. [6] When this stage is completed, it is signified by a separation of approximately 7.0 to 8.0 mm in mantle length. [6]
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.
Doryteuthis opalescens, the opalescent inshore squid or market 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.
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 the Mediterranean Sea. It is also known from the Indian Ocean.
The Japanese flying squid, Japanese common squid or Pacific flying squid, scientific name Todarodes pacificus, is a squid of the family Ommastrephidae. This animal lives in the northern Pacific Ocean, in the area surrounding Japan, along the entire coast of China up to Russia, then spreading across the Bering Strait east towards the southern coast of Alaska and Canada. They tend to cluster around the central region of Vietnam.
The colossal squid is the largest member of its family Cranchiidae, the cockatoo or glass squids, with its second largest member being Megalocranchia fisheri. 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 at 9–10 metres (30–33 ft). The colossal squid has the largest eyes of any known creature ever to exist, with an estimated diameter of 27 cm (11 in).
The neon flying squid, sometimes called the red flying squid, akaika, and red squid is a species of large flying squid in the family Ommastrephidae. They are found in subtropical and temperate oceanic waters globally.
Ommastrephinae is a subfamily of squids under the family Ommastrephidae.
Heteroteuthis dispar, also known as the odd bobtail, is a small deep water squid found in the North Atlantic Ocean and the Mediterranean Sea.
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.
Illex coindetii, commonly known as the southern shortfin squid or broadtail shortfin squid, is a species of neritic squids in the family Ommastrephidae. They are found in the Mediterranean Sea and on both sides of the north Atlantic Ocean.
Illex illecebrosus, commonly known as the northern shortfin squid, is a species of neritic squids in the family Ommastrephidae. Squids of the genus Illex account for 65% of the world's cephalopod captures. Illex is formed by four taxa distributed throughout the Atlantic Ocean, whose identification and phylogenetic relationships based on morphological characters remain controversial.They are found in the northwest Atlantic Ocean, from off the coast of eastern North America to Greenland, Iceland, and west of Ireland and the United Kingdom. They are a highly migratory and short-lived species, with lifespans of less than a year. They are commercially important and are fished extensively, mostly for the Canadian and Japanese markets.
Sthenoteuthis pteropus, also known as the orangeback flying squid or orangeback squid, is a species of cephalopod in the family Ommastrephidae. It is native to tropical parts of the Atlantic Ocean where it is found to depths of about 200 m (656 ft).
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.
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.
The Angolan flying squid is a species of squid from the subfamily Todarodinae, part of the family Ommastrephidae. 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 circumglobal distribution in the seas around the lower latitudes of the Southern Ocean.
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.
Nototodarus gouldi, also known as the Gould's squid, Gould's flying squid, or arrow squid, is a squid belonging to the family Ommastrephidae. It inhabits the tropical and temperate waters of Australia and New Zealand. It is frequently caught and eaten for food. They live up to one year.
| Authority control databases: National |
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