''Opisthoteuthis borealis'' is a lesser-known species of octopus found near Greenland and Iceland, especially in the Davis Strait. The species was described from 9 specimens, and is one of the most recent

Opisthoteuthis ''Opisthoteuthis'' is a genus of cirrate octopuses, sometimes known as flapjack octopuses, which are found in all the world's oceans. Behavior Like other cirrates, octopuses in Opisthoteuthis are generally small, and many dwell in the deep sea ...

species described. Not much is known about it besides its anatomy and habitat.

Description

''Opisthoteuthis borealis'' belongs to the order

Cirrata Cirrina or Cirrata is a suborder and one of the two main divisions of octopuses. Cirrate octopuses have a Cirrate shell, small, internal shell and Cephalopod fin, two fins on their head, while their sister suborder Incirrina has neither. The fins ...

, a subdivision of octopuses which have fleshy fins to assist in swimming, internal shells supporting their bodies, and two threadlike structures called

cirri Giovanni Battista Cirri (1 October 1724 – 11 June 1808) was an Italian cellist and composer in the 18th century. Biography Cirri was born in Forlì in the Emilia-Romagna Region of Italy. He had his first musical training with his brother ...

for each sucker. Many cirrate octopuses live in deep water. Octopuses in the species ''Opisthoteuthis borealis'' have mantles up to long. They are medium-sized when compared to closely related species. They have long arms and large eyes. Males of ''O. borealis'' have some enlarged suckers; their purpose is unknown. Females don't have enlarged suckers. This specific kind of sex difference, or

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

, is also seen in

Opisthoteuthis albatrossi ''Opisthoteuthis albatrossi'' (common name in ja, オオクラゲダコ) is a cirrate octopus originally found off Kinkasan in Japan. This species was described from only four specimens. It is similar to '' Opisthoteuthis californiana;'' the tw ...

and

Opisthoteuthis californiana ''Opisthoteuthis californiana'', also known as the flapjack octopus or adorabilis, is a species of umbrella octopus. Description The flapjack octopus usually appear pinkish. They have fins above their eyes, similar to those found on some speci ...

. Some of the males' arms are thickened compared to the arms of females. Anatomically, this species is most similar to '' Opisthoteuthis grimaldii''.

Habitat

Of all species of ''

'' found in the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

, ''O. borealis'' lives the furthest north. They are found near Greenland and Iceland at depths of deep. They live in waters with a small temperature range of . These octopuses occupy the

benthic zone The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning " ...

, on and just above the seafloor. The species is of little or no interest to fisheries.

References

{{Taxonbar, from=Q13930548 Molluscs described in 2005 Octopuses Cephalopods of North America Molluscs of the Atlantic Ocean