| Greater hooked squid | |
|---|---|
 | |
| Mature female (384 mm (15.1 inches)ML, 1.875 kg (4.13 lb) weight) from theChatham Rise | |
 | |
| ~400 mm ML | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Order: | Oegopsida |
| Family: | Onychoteuthidae |
| Genus: | Moroteuthopsis |
| Species: | M. ingens |
| Binomial name | |
| Moroteuthopsis ingens | |
| Synonyms | |
| |
Moroteuthopsis ingens, thegreater hooked squid, is a species ofsquid in the familyOnychoteuthidae. It occurs worldwide insubantarctic oceans.
M. ingens was long attributed to the genusMoroteuthis, which became ajunior synonym ofOnykia in 2010; this species was subsequentlylumped into that genus, though it was separated from all otherOnykia spp. into its ownsubgenus;Moroteuthopsis.[3] A 2018 study ofmitochondrial DNA of the family Onychoteuthidae subsequently found that the subgenusMoroteuthopsis was deemed distinct from the rest ofOnykia, and furthermore, this species formed amonophyletic clade withKondakovia longimana. Thus, it was decided to elevate subgenusMoroteuthopsis into a full genus, and this species became its type species by seniority, with"K." longimana becoming the second species inMoroteuthopsis.[4]
The size of a fully grownM. ingens including the clubbed tentacles is currently unknown. Many estimates, however, predict that themantle may reach lengths of up to 94 cm (37 in). Research has found that egg sizes of the squid average 2.1 mm inside mature females, while juveniles average 4.6 mm (0.18 in) or larger. Juveniles are presumed to live near the surface, until they reach a mantle length of approximately 200 mm (7.9 in), at which time they relocate to deeper water, and larger prey.M. ingens exhibitsexual dimorphism, with females growing linearly twice as fast as males, and reaching a fully mature weight of more than five times that of male counterparts.[5]
Penis elongation has been observed in this species; whenerect, the penis may be as long as the mantle, head and arms combined.[6][7] As such, deep water squid likeM. ingens have the greatest known penis length relative to body size of all mobile animals, second in the entire animal kingdom only to certain sessilebarnacles.[6]
It is generally accepted that there are large dietary variations between large and smallM. ingens. One of the most common findings is that juvenile squid (>200 mm ML) consume a greater percentage ofcrustaceans andcephalopods compared to their size than mature squid, which consume a large percentage offish and virtually no crustaceans.[8]Myctophid lantern fish are seen as common prey, globally.[9] Larger squid are known to practice cannibalism (accounting for up to 6% of diet).[10]
M. ingens, as with many (if not all) large squid, has a number of predators. These include thepatagonian toothfish,king penguin,wandering albatross,pilot whale,bottlenose whale,dwarf sperm whale,sperm whale, and other types of squid.[11] Other predators includeAntarctic andSubantarctic fur seals.
