''Octopus tehuelchus'', commonly known as the Patagonian octopus, is a species of

octopus An octopus (: octopuses or octopodes) is a soft-bodied, eight-limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids. Like oth ...

, a marine

cephalopod A cephalopod is any member of the molluscan Taxonomic rank, class Cephalopoda (Greek language, Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral symm ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

of the

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Octopoda. It is native to shallow waters in the subtropical southwestern

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

. It was first described in 1834 by the French naturalist

Alcide d'Orbigny Alcide Charles Victor Marie Dessalines d'Orbigny (6 September 1802 – 30 June 1857) was a French naturalist who made major contributions in many areas, including zoology (including malacology), palaeontology, geology, archaeology and anthropol ...

Description

This is a small to medium-sized octopus with a maximum length of about . The mantle is globular with a smooth surface. The head is slightly narrower than the mantle, the eyes are prominent and are surrounded by small granulations. The mantle opening is wide with a long funnel. The neck is constricted and the eight arms are two-thirds to three-quarters of the length of the rest of the animal. The second pair of arms is the shortest and the fourth pair is the longest. The

hectocotylus A hectocotylus (: hectocotyli) is one of the arms of male cephalopods that is specialized to store and transfer spermatophores to the female. Structurally, hectocotyli are muscular hydrostats. Depending on the species, the male may use it merel ...

of the male is on the right third arm, and the male also has enlarged suckers.

Distribution and habitat

''Octopus tehuelchus'' is native to the subtropical southwestern Atlantic Ocean. Its range extends along the coasts of Brazil and Argentina between 30°S and 44°S, and between 50°W and 65°W. It occurs in the

intertidal zone The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various ...

and the shallow

subtidal zone The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth. From the point of view of marine biology it forms a relatively stable and well-illuminated ...

, down to depths of around . It occurs over reefs and sandy seabeds, often hiding in crevices or under boulders and in empty

mollusc shells The mollusc (or mollusk) shell is typically a calcareous exoskeleton which encloses, supports and protects the soft parts of an animal in the phylum Mollusca, which includes snails, clams, tusk shells, and several other classes. Not all shelled ...

Ecology

This octopus feeds on crabs and small

clam Clam is a common name for several kinds of bivalve mollusc. The word is often applied only to those that are deemed edible and live as infauna, spending most of their lives halfway buried in the sand of the sea floor or riverbeds. Clams h ...

s and is known to drill into

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

shells to extract

hermit crab Hermit crabs are anomuran Decapoda, decapod crustaceans of the superfamily (taxonomy), superfamily Paguroidea that have adapted to occupy empty scavenged mollusc shells to protect their fragile exoskeletons. There are over 800 species of hermit c ...

s. The octopus is itself heavily preyed on by young

shark Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...

s off the coast of Argentina. Breeding in this species takes place between autumn and spring. As with many other octopus species, the female selects a shelter and broods a batch of eggs. An invertebrate shell is usually chosen as a shelter; small individuals usually choose gastropod shells such as '' Zidona dufresnei'', ''

Odontocymbiola magellanica ''Odontocymbiola magellanica'', also known as the Magellan whelk or Magellan Venus, is a species of sea snail, a marine gastropod mollusc in the family Volutidae, the volutes. It is the largest extant species of volute in the world, reaching up ...

'' or ''

Buccinanops cochlidium ''Buccinanops cochlidium'', common name the gradated bullia, is a species of sea snail, a marine gastropod mollusk in the family Nassariidae, the Nassa mud snails or dog whelks.Rosenberg, G. (2015). Buccinanops cochlidium (Dillwyn, 1817). In: Mo ...

'',

s such as '' Pitar rostratus'' or '' Amiantis purpurata'' or large

barnacle Barnacles are arthropods of the subclass (taxonomy), subclass Cirripedia in the subphylum Crustacean, Crustacea. They are related to crabs and lobsters, with similar Nauplius (larva), nauplius larvae. Barnacles are exclusively marine invertebra ...

s in the genus ''

Balanus ''Balanus'' is a genus of barnacles in the family Balanidae of the subphylum Crustacea. This genus is known in the fossil record from the Jurassic to the Quaternary periods (age range: from 189.6 to 0.0 million years ago.). Fossil shells withi ...

''. Medium-sized individuals favour shells of the

oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but no ...

'' Ostrea puelchana'', while the largest individuals create their own shelters from shell fragments and other materials. The oyster is the most favoured shelter overall, with the majority of eggs being deposited inside the concave valve.

References

{{Taxonbar, from=Q3198523 Octopodidae Cephalopods described in 1834