''Cirroteuthis muelleri'' was the first cirrate octopus species (and genus) to be scientifically described (in 1836). It is closely related to the genus ''Cirrothauma'' within the family Cirroteuthidae. At present the genus contains a single recognized species restricted to the Arctic Ocean and northern basins of the Atlantic and Pacific, but other species may be present in the southern hemisphere.Vecchione, M. & R.E. Young 2003
''Cirroteuthis'' Eschricht, 1836
The Tree of Life Web Project.

Description

''Cirroteuthis muelleri'' can reach a maximum length of 400 mm (mantle length 170 mm). Statements that ''C. muelleri'' reaches up to 1.5 m total length are erroneous (and involve unidentified ''

Cirrothauma ''Cirrothauma'' is a genus of deep water octopuses from the cirrate family Cirroteuthidae. The species ''Cirrothauma'' are fragile, gelatinous deep-sea octopods with a shell, a moderate saddle, and triangular wings. Their eyes either have lenses ...

'', then regarded as ''Cirroteuthis'' sp., being mistakenly assumed to be ''C. muelleri''). It is off white or pale purple, with the inner side of the arms and the webs being brownish-purple. The head has well developed eyes with lenses. The upper and lower beaks are thin and relatively weak. The body is gelatinous and fragile. The arms are nearly equal in length. A pair of translucent webs joins the dorsal and ventral sides of the arms together and the webs terminate at a nodule. The first 7 or 8 suckers are cup-shaped and raised on thick stalks, numbers 2 and 3 being the largest. There are a further 30 or so smaller suckers with delicate stalks. Between the suckers are conspicuous cirri up to long. These are elongate, fleshy tendrils set along the sides of the oral surface of the arms, the longest being in the mid-arm region. Both the suckers and the cirri do not extend as far as the tip of the arm.''Cirroteuthis muelleri''
Marine Species Identification Portal. Retrieved 2011-10-03. The fins are elliptical when viewed from the side. They are wide, and longer than the width of the head. The aperture of the mantle is narrow and the funnel is long. It has been nicknamed "Dumbo" after the cartoon elephant of that name, because its fins resemble large ears.
NOAA Ocean Explorer. Retrieved 2011-10-03. Cirroteuthis muelleri NOAA

Distribution

''Cirroteuthis muelleri'' is a deep sea species. It is found in cold seas in the

boreal Boreal may refer to: Climatology and geography *Boreal (age), the first climatic phase of the Blytt-Sernander sequence of northern Europe, during the Holocene epoch *Boreal climate, a climate characterized by long winters and short, cool to mild ...

Arctic, the north Atlantic Ocean, and the north Pacific Ocean. In the southern hemisphere at least three specimens have been captured of ''Cirroteuthis'' cf. ''muelleri'' from New Zealand and Australia, which may represent a new species.

Habitat

''Cirroteuthis muelleri'' is benthopelagic, meaning it is found swimming or drifting in the or so immediately above the

sea bed The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'. The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...

. It is usually found at depths of over . At these depths, practically no light penetrates, the temperature is about 4 °C, and observation is only possible by

submersible A submersible is a small watercraft designed to operate underwater. The term "submersible" is often used to differentiate from other underwater vessels known as submarines, in that a submarine is a fully self-sufficient craft, capable of ind ...

, which makes these octopuses difficult to collect. Their ecology and biology are little known, but they seem to be fairly common in the seas around

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...

Biology

In a study of Arctic cephalopods, three specimens of ''Cirroteuthis muelleri'', all female, were caught near the ocean floor at . The eggs were found to be large and were laid on the bottom, singly. The diet of ''C. muelleri'' (from stomach contents of 18 specimens) was found to comprise small crustaceans (

Calanoida Calanoida is an order of copepods, a group of arthropods commonly found as zooplankton. The order includes around 46 families with about 1800 species of both marine and freshwater copepods between them. Description Calanoids can be distinguis ...

Mysidacea The Mysidacea is a group of shrimp-like crustaceans in the superorder Peracarida, comprising the two extant orders Mysida and Lophogastrida and the prehistoric Pygocephalomorpha The order Pygocephalomorpha is an extinct group of peracarid c ...

Isopoda Isopoda is an order of crustaceans that includes woodlice and their relatives. Isopods live in the sea, in fresh water, or on land. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed limbs on the thorax, an ...

) and polychaetes (

Polynoidae Polynoidae is a family of marine Polychaete worms known as "scale worms" due to the scale-like elytra on the dorsal surface. Almost 900 species are currently recognised belonging to 9 subfamilies and 167 genera. They are active hunters, but gene ...

), all small benthic or epibenthic prey items. The largest mysids consumed were estimated at 14.6 mm long, and the largest polychaete was estimated at 24.3 mm.

References

{{Taxonbar, from=Q18195570 Octopuses Monotypic mollusc genera Cephalopods of Oceania Molluscs of the Pacific Ocean Molluscs of the Atlantic Ocean