| Octopus, Cephalopod, Molluscs, Caribbean reef octopus, California two‑spot octopus|
The Atlantic pygmy octopus (Octopus joubini), also known as the small-egg Caribbean pygmy octopus, is a small octopus species in the order Octopoda. Fully grown, this cephalopod reaches a mantle length of 4.5 cm (1.8 in) with arms up to 9 cm (3.5 in) long. They are known for being intelligent creatures with keen senses, particularly good sight.
O. joubini often seeks shelter from predators in empty clamshells, cans or small openings, pulling the opening closed with its arms, combining sand and gravel to form a lid. It employs the two defensive mechanisms typical of all octopuses: ink sacs and camouflage. All Cephalopods have chromatophores, special pigmented and light reflecting cells on their skin which allows them to change colour and texture quickly.
Females of this species breed between March and June, laying elliptical, amber eggs in a sheltered place. The hatchlings are relatively small (0.04 g), but are fully formed and can hunt within hours. They reach maturity in around 182 days and weigh about 30 g at this time.
Like all octopuses, O. joubini is carnivorous. It is able to bore into the hard shells of small clams, crustaceans, or other creatures. It uses its radula, a small, spikey, tongue like structure, to drill a hole in the prey's shell, and proceeds to secrete poisonous saliva out of its beak to paralyze its victim. While the Atlantic pygmy octopus feeds primarily on small crustaceans, only a few species have been recorded as prey of this species in the wild. In laboratory conditions, this diet is expanded considerably.
Atlantic pygmy octopus Wikipedia