Umbrella octopus

thumb|[[Opisthoteuthis extensa]]

thumb|[[Opisthoteuthis medusoides]]

Opisthoteuthidae, from Ancient Greek ὄπισθεν (ópisthen), meaning "back", and τευθίς (teuthís), meaning "squid", known as umbrella octopuses, are a group of pelagic octopuses. Umbrella octopuses are characterized by a web of skin between the arms, causing them to somewhat resemble an opened umbrella when the arms are spread.

Description

Opisthoteuthidae are a group of octopuses characterized by a web of skin in between their arms. They have a broad U-shaped shell that support muscles for a pair of small fins on the mantle, these fins are far less developed than other families in Cirrina and essentially only act as stabilizers when the animal swims (using a medusoid motion of the arms and webbing). This structure makes the umbrella octopus resemble an umbrella when they spread their arms/web out. The structure of the umbrella octopus has the oral surface below the mantle of the octopuses and the web with their arms surround the bottom of the mantle. Their outer skin has a very delicate consistency that results in white spots appearing on their skin when damaged. They have also been found in the South China Sea. They stay within 3,000-4,000 meters below sea level and try to stay hovering over the ocean floor.

Taxonomy

Family Opisthoteuthidae has classically contained a single genus, Opisthoteuthis, which has recently been split into three genera on the basis of differences in enlarged suckers on male specimens. Genera Grimpoteuthis, Luteuthis, and Cryptoteuthis now are included in the family Grimpoteuthidae.

Genus Opisthoteuthis Verrill, 1883
Exsuperoteuthis depressa Ijima & Ikeda, 1895 (Synonym Opisthoteuthis japonica Taki, 1962)
Exsuperoteuthis persephone Berry, 1918
Genus Insigniteuthis Verhoeff, 2024
Insigniteuthis calypso Villanueva, Collins, Sánchez & Voss, 2002 [Possibly attributable to genus Insigniteuthis