Common blanket octopus

[5] Males and small females of less than 7 cm have been reported to carry with them the tentacles of the Portuguese man o' war.

The web between the arms of the mature female octopus serves as a defensive measure as well, making the animal appear larger, and being easily detached if bitten into by a predator.

[6] The complete mitogenome of T. violaceus is a circular double-stranded DNA sequence that is 16,015 base-pairs long.

[5] The common blanket octopus exhibits one of the highest degrees of sexual size-dimorphism found in large animals.

So selection may have favoured males to remain small in order to continue to utilize this defence mechanism.

[5] Predators of the common blanket octopus include the blue shark,[8] tuna,[9] and the billfish.

Distribution of Tremoctopus violaceus
Distribution of Tremoctopus violaceus