Common name: Bobtail squid

General information

The Pygmy Squid, Idiosepius pygmaeus, is one of the smallest cephalopods in the world. Its diminutive size and cryptic behavior make it a fascinating addition to specialized marine aquariums. Despite its common name, it is not a true squid but belongs to a separate family, Idiosepiidae, which is characterized by its unique adhesive structure on the dorsal side of the mantle, allowing it to attach to surfaces including seagrass blades.

Care

Caring for Pygmy Squids requires a species-specific setup due to their small size and specialized needs. They thrive in mature, stable aquariums with plenty of live rock and hiding places. A varied diet of small live foods such as mysid shrimp and copepods is essential for their well-being. Due to their short lifespan, typically less than a year, and delicate nature, they are recommended for experienced aquarists.

Reproduction

Pygmy Squids are known for their unique mating behavior where the male uses a specialized arm to transfer a spermatophore directly into the female's mantle cavity. Females lay individual eggs on substrates such as seagrass or aquarium glass. The eggs hatch into miniature versions of the adults, bypassing a larval stage, which can be an advantage in captive breeding.

Habitat

Idiosepius pygmaeus is found in shallow coastal waters and estuaries, often associated with seagrass beds and algae. They are native to the Western Pacific, including areas around Japan, the Philippines, and Northern Australia. Their natural habitat includes waters with gentle currents and abundant microfauna for feeding.