| Taoniinae | |
|---|---|
 | |
| Sandalops melancholicus | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Order: | Oegopsida |
| Family: | Cranchiidae |
| Subfamily: | Taoniinae Pfeffer, 1912 [1] |
| Type genus | |
| Taonius Steenstrup, 1861 | |
| Genera | |
Bathothauma Contents | |
| Synonyms [2] | |
| |
Taoniinae is a subfamily containing ten genera of glass squids.
Unlike Cranchiinae Pfeffer, 1912, the other subfamily within Cranchiidae Prosch, 1847, Taoniinae all lack cartilaginous strips that extend back from the funnel-mantle point of fusion. Their funnels are free laterally, and they have one to three photophores on the eyes. [3] The largest photophore is crescent-shaped for most genera, but it's triangular in Helicocranchia , a semicircle in Bathothauma , and circular in Sandalops . This is in contrast to glass squids in the subfamily Cranchiinae, which have at least four small photophores which are round or oval. [2]
In addition, males lack hectocotyli; these are arms that have evolved to specialize in the storage and transfer of spermatophores to females. [4] Taoniinae are also often larger than Cranchiinae and have darker beaks. [5] Another characteristic is that Taoniinae's caecum, is smaller than its stomach; in Cranchiinae, the caecum is larger than the stomach. [6]
When Georg Johann Pfeffer circumscribed this subfamily in 1912, he grouped its genera into three tribes: [1]
Synonyms of Taoniinae include Galiteuthinae Berry, 1912 and Teuthoweniinae Grimpe, 1922. [2] S. Stillman Berry's 1912 circumscription of the subfamily Galiteuthinae only consisted of its type genus Galiteuthis Joubin, 1898. Like Pfeffer's Taoniinae, this was a subfamily within the family Cranchiidae Prosch, 1847. This was in contrast to Louis Joubin's classification, which placed Galiteuthis in a new, distinct family: CranchionychiaeJoubin, 1898. [14] [2] Georg Grimpe's 1922 circumscription of Teuthoweniinae included its type genus Teuthowenia Chun, 1910 as well as HensenioteuthisPfeffer, 1900, [h] Helicocranchia Massy, 1907, and Sandalops Chun, 1906. He placed the genus Bathothauma Chun, 1906 into a new family, Bathothaumatidae Grimpe, 1922, now just treated as a junior synonym of Cranchiidae. Subsequent research did not pay much heed to Grimpe's taxonomy. [2]
Below is Nancy A. Voss and Robert S. Voss's 1983 proposal for a phylogeny of the Taoniinae subfamily. [16] [17]
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As of 2017 [update] , the World Register of Marine Species classifies the Taoniinae as containing ten genera; they classify Belonella as a synonym of Taonius following Nancy A. Voss. [18] However, Patrizia Jereb and Clyde F. E. Roper recognize Belonella as a distinct genus from Taonius, although they also note they are frequently synonymized. Jereb and Roper also note Kir Nazimovich Nesis and Takashi Okutani as teuthologists who rejected Voss's synonymization of Belonella. [6] Nesis's classification had Taonius consisting of only the single species T. pavo, and had Belonella consisting of B. beloneChun, 1906, B. borealisNesis, 1972 and an undescribed species from the Antarctic. [19]
The family Cranchiidae comprises the approximately 60 species of glass squid, also known as cockatoo squid, cranchiid, cranch squid, or bathyscaphoid squid. Cranchiid squid occur in surface and midwater depths of open oceans around the world. They range in mantle length from 10 cm (3.9 in) to over 3 m (9.8 ft), in the case of the colossal squid. The common name, glass squid, derives from the transparent nature of most species. Cranchiid squid spend much of their lives in partially sunlit shallow waters, where their transparency provides camouflage. They are characterised by a swollen body and short arms, which bear two rows of suckers or hooks. The third arm pair is often enlarged. Many species are bioluminescent organisms and possess light organs on the undersides of their eyes, used to cancel their shadows. Eye morphology varies widely, ranging from large and circular to telescopic and stalked. A large, fluid-filled chamber containing ammonia solution is used to aid buoyancy. This buoyancy system is unique to the family and is the source of their common name "bathyscaphoid squid", after their resemblance to a bathyscaphe. Often the only organ that is visible through the transparent tissues is a cigar-shaped digestive gland, which is the cephalopod equivalent of a mammalian liver. This is usually held in a vertical position to reduce its silhouette and a light organ is sometimes present on the lower tip to further minimise its appearance in the water.
The Mastigoteuthidae, also known as whip-lash squid, are a family of small deep-sea squid. Approximately 20 known species in six genera are represented, with members found in both the mesopelagic and bathypelagic zone of most oceans. Originally described by Verill in 1881, it was later lowered by Chun (1920) to a subfamily (Mastigoteuthinae) of the Chiroteuthidae. However, Roper et al. (1969) raised it back to the family level, and this has not been changed since. The taxonomy of this family is extremely unstable, and there have been at times one genus, two genera and four subgenera(Salcedo-Vargas & Okutani, 1994), two genera and several 'groups', five genera and one species with an uncertain placement, or six genera.
The hooked squid, family Onychoteuthidae, currently comprise about 20–25 species, in six or seven genera. They range in mature mantle length from 7 cm (2.8 in) to a suggested length of 2 m for the largest member, Onykia robusta. The family is characterised by the presence of hooks only on the tentacular clubs, a simple, straight, funnel–mantle locking apparatus, and a 'step' inside the jaw angle of the lower beak. With the exception of the Arctic Ocean, the family is found worldwide.
Pholidoteuthis is a genus of squid in the monotypic family Pholidoteuthidae, comprising at least two species. The defunct genus Tetronychoteuthis was previously incorporated into Pholidoteuthidae based upon a singular taxon known as Tetronychoteuthis massyae. Following the discovery of Pholidoteuthis boschmai in 1950, T. massaye was placed into Pholidoteuthis, with Tetronoychoteuthis considered a nomen dubium. P. boschmai is now considered a junior synonym of P. massyae.
Umbrella octopuses are a group of pelagic octopuses. Umbrella octopuses are characterized by a web of skin between the arms, causing them to somewhat resemble an opened umbrella when the arms are spread.
Abralia is a genus of squid comprising around 20 species from the family Enoploteuthidae. They are small squid which can be found in the epipelagic to mesopelagic zones while some species are found in water with shallow substrates on steep slopes on the boundary of the mesopelagic zone. They are distinguished from other members of the Enoploteuthidae by not normally having large, black photophores at the tips of arms IV, although if these are present they are not covered in black chromatophores, and having fins which extend beyond their tail. The photophores of the integument are characteristicand are found in the three types. "Lensed" photophores are a blue color with a white ring, "simple" photophores are small and violet-colored and the "complex" photophores are surrounded by small green satellite points and have a green centre. The complex photophores will frequently appear to be blue depending on their physiological state. The integument also has small black chromatophores which look like dots. They have 5–12 variably sized photophores on the eye. Either the right or left arm IV is hectocotylized.
Megalocranchia is a genus of glass squids. It occurs circumglobally in tropical and subtropical waters.
Galiteuthis is a genus of glass squids from the family Cranchiidae and the subfamily Taoniinae. Squids in the genus Galiteuthis are large squids with mantle lengths measuring up to 660 mm (26 in), although it has been suggested that mantle length could reach as much as 2.7 m. The most distinctive feature of the speciesa in this genus are they have hooks on the tentacular clubs while there are no hooks on the arms, and by their long, thin, terminal fins.
Taonius is a small genus of glass squid. Although it comprises only three recognised species, it has been suggested there may be as many as five species. Taonius borealis is found in the North Pacific Ocean and Taonius pavo is found in the Atlantic and possibly the south-western Indian Ocean.
Teuthowenia is a genus of glass squid in the subfamily Taoniinae. Members of this genus are characterized by their deep-sea habitat, clear bodies, and ability to engorge themselves with water to become larger when threatened. Each known species has a visible digestive gland, which serves a similar purpose as a stomach and liver.
Taningia is a genus of squid in the family Octopoteuthidae. For over 150 years, it has been believed to comprise a single species known as Taningia danae. Recently it has been shown to contain at least two new species. Another species, Taningia persica, has historically been referred to but has been questioned.
Mastigoteuthis is a genus of whip-lash squid containing at least seven valid species. Some teuthologists consider Idioteuthis synonymous with this taxon.
Galiteuthis phyllura, also known as the cockatoo squid, is a species of glass squid, possibly the largest in the genus.
Sepietta petersi, also known as the mysterious bobtail, is a species of bobtail squid native to the Mediterranean Sea. A doubtful record of S. petersi also exists from the Atlantic Ocean off Morocco.
Graneledone is a genus of octopuses in the family Octopodidae. The type species is Eledone verrucosaVerrill, 1881.
Galiteuthis armata, the armed cranch squid, is a large species of glass squid. It reaches a mantle length of 61 cm (24 in). The species is native to the Atlantic Ocean and has been recorded from Bermuda, Canada, Namibia, and Spain. Armed cranch squids often appear to have bloated bodies, short arms, with thin but muscular mantles. They also contain large buoyancy chambers.
Cycloteuthis sirventi, commonly known as Sirvent's disc-fin squid, is a species of squid in the family Cycloteuthidae, of which it is the most common. It is possible that C. akimushkini is a junior synonym of C. sirventi. The species occurs in the tropical to polar western Atlantic Ocean. It has a maximum mantle length of 500mm.
Teuthowenia megalops, sometimes known as the Atlantic cranch squid, is a species of glass squid from the subarctic and temperate waters of the northern Atlantic Ocean. They are moderately sized squid with a maximum mantle length of 40 cm (16 in). Their very large eyes are the source for the specific name megalops. Like other members of the genus Teuthowenia, they are easily recognizable by the presence of three bioluminescent organs (photophores) on their eyeballs.
Macrotritopus is a poorly known genus of octopuses in the family Octopodidae. As it stands, Macrotritopus contains two valid described species, Macrotritopus defilippi from the NE Atlantic and Mediterranean, and Macrotritopus beatrixi from the Caribbean and SW Atlantic. Two poorly described, unresolved taxa are known only from planktonic hatchlings, and a further three undescribed Indo-Pacific species may be attributable to this genus.
Cranchioidea is a superfamily of squid in the order Oegopsida. They form the most basal clade within the order.
