''Brachioteuthis riisei'', also known as the common arm squid, is a species of squid in the family

Brachioteuthidae Brachioteuthidae is a family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of ...

Description

This is a small species. It is almost colourless except for small chromatophores scarcely distributed. It has a long, thin, cylindrical mantle which grows to from 10 to 17 cm in length. The fin is approximately 35-50% of the length of the mantle. It has weak muscles, yet is

nekton Nekton or necton (from the ) refers to the actively swimming aquatic organisms in a body of water. The term was proposed by German biologist Ernst Haeckel to differentiate between the active swimmers in a body of water, and the passive organisms t ...

ic.

Larval stage

The neck of the larvae is long. Their arms have two rows of suckers, with the having multiple rows of smaller suckers in the tentacular club at the proximal hub.

Distribution

This species is widely distributed and is native to many parts of the Atlantic and Pacific Oceans, and the Mediterranean and Black Seas. Except within the boreal Pacific Ocean, this is likely a cosmopolitan species.

Habitat and biology

Young animals live in the epi- mesopelagic zone, with adults occurring in the

bathypelagic zone The bathypelagic zone or bathyal zone (from Greek βαθύς (bathýs), deep) is the part of the open ocean that extends from a depth of below the ocean surface. It lies between the mesopelagic above, and the abyssopelagic below. The bathypelagi ...

. ''Brachioteuthis riisei'' is an oceanic species which can be found over a wide range of depths from the surface to 3,000 m depth. Juvenile animals occur throughout the year which suggests that this species has an extended spawning season, although the juveniles reach peak abundance between May and August and in February in the North Atlantic while the peaks in the Mediterranean and off Northwest Africa are from April to July, in September, and from December to February. ''Brachioteuthis riisei'' is preyed upon by a range of marine mammals including

Cuvier's beaked whale The Cuvier's beaked whale, goose-beaked whale, or ziphius (''Ziphius cavirostris'') is the most widely distributed of all beaked whales in the family Ziphiidae. It is smaller than most baleen whales yet large among beaked whales. Cuvier's beaked ...

(''Ziphius cavirostris'') and

striped dolphin The striped dolphin (''Stenella coeruleoalba'') is an extensively studied dolphin found in temperate and tropical waters of all the world's oceans. It is a member of the oceanic dolphin family, Delphinidae. Taxonomy The striped dolphin is one o ...

(''Stenella coeruleoalba''), as well as by fish, for example the blue shark (''Prionace glauca'') and, in the

Azores ) , motto =( en, "Rather die free than subjected in peace") , anthem= ( en, "Anthem of the Azores") , image_map=Locator_map_of_Azores_in_EU.svg , map_alt=Location of the Azores within the European Union , map_caption=Location of the Azores wi ...

, the swordfish (''Xiphias gladius''), as well as by the giant red shrimp (''

Aristaeomorpha foliacea ''Aristaeomorpha foliacea'', the giant red shrimp or giant gamba prawn, is a species of deep water benthopelagic decapod crustacean. It is found in all the world's oceans in the temperate and tropical zones. It is subject to some commercial fish ...

'') in the Sicilian Channel.

References

{{Taxonbar, from=Q2148844 Squid Molluscs described in 1882 Marine molluscs of Europe Cephalopods of Europe