Tropical Western Atlantic:

Florida, Gulf of Mexico, Caribbean Sea to Guyanas, Bahamas, West Indies.

Biogeographic Regions: atlantic ocean (Native )

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Small; maximum length (including arms) approximately 15 cm. Like all octopuses, Joubin's octopus has 8 arms. One arm, the ligula, is modified in males to form a sex organ. Octopus joubini has smooth skin with small pimples scattered at intervals.

Inhabit empty shells among coral, near low tide line and below in shallow water. They use crevices, empty clam shells, or spaces in a reef face to eat and rest.

Aquatic Biomes: benthic ; reef ; coastal

Habitat Type: Marine

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Mainly feed on crabs, e.g., Uca fiddler crabs, but also consume snails. Prefer crabs, possibly because they come into more contact with them, and crabs are more active than snails. The octopus seems to spend long periods of time pulling snails out of their shells before consuming them, but they can kill and eat a crab in one minute or less.

Actual mating time is usually brief, about 5 minutes, as compared with other species like the Octopus dofleini, which mates for 2-3 hours. Amount of contact and sex of the initiator seems to vary. As a result of its small size, the animal is vulnerable to many predators. A shorter mating time shortens the period of vulnerability to these predators. It can occasionally cause problems, however. The sperm is passed to the female through a spermatophore that the males, using a special arm, place in the female's mantle cavity. The spermatophore evaginates in the female's oviduct, releasing sperm. Usually males would hold the spermatophore in the female until this process is complete, but in this case the male cannot because the fertilization takes too long. The eggs produced are usually fairly large, 6-8 mm in length. The females begin spawning from 4-5 months after hatching, with death shortly after 30-45 day brooding period.

At present there is an argument over whether the Octopus joubini is a synonym of either O. mercatoris or an as-yet undescribed species. Possible differences between the two supposed species include coloration, egg size, and hatchling ecology.

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Reasons: This is a common marine species (Abbott, 1958).

Possible effect on crab populations in the area.

Used in research, both behavioral and biomedical.