Size and growth The size of a fully grown
M. ingens including the clubbed tentacles is currently unknown. Many estimates, however, predict that the
mantle may reach lengths of up to . Research has found that egg sizes of the squid average 2.1 mm inside mature females, while juveniles average or larger. Juveniles are presumed to live near the surface, until they reach a mantle length of approximately , at which time they relocate to deeper water, and larger prey.
M. ingens exhibit
sexual 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.
Penis elongation has been observed in this species; when
erect, the penis may be as long as the mantle, head and arms combined. As such, deep water squid like
M. ingens have the greatest known penis length relative to body size of all mobile animals, second in the entire animal kingdom only to certain sessile
barnacles.
Myctophid lantern fish are seen as common prey, globally. Larger squid are known to practice cannibalism (accounting for up to 6% of diet).
M. ingens, as with many (if not all) large squid, has a number of predators. These include the
patagonian toothfish,
king penguin,
wandering albatross,
pilot whale,
bottlenose whale,
dwarf sperm whale,
sperm whale, and other types of squid. Other predators include
Antarctic and
Subantarctic fur seals. Image:Morotuthis ingens2.jpg|Tentacular club of
Moroteuthopsis ingens Image:Moroteuthis ingens3.jpg|Piece of ventral mantle skin Image:Moroteuthis ingens4.jpg|
Gladius with cross-sections ==References==