''Eledone gaucha'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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 ...

from the southern

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 is a predator of fish, crabs, lobsters and molluscs. This octopus is a member of the genus ''

Eledone ''Eledone'' is a genus of octopuses forming the only genus in the family (biology), family Eledonidae. It is mainly distributed in the northern and southern Atlantic Ocean, with one species, ''Eledone palari, E. palari'', described from the south ...

'' and belongs to the family Eledonidae. It was distinguished from a similar species, '' Eledone massyae''. ''Eledone gaucha'' is smaller in size than '' E. massyae'' and has a smaller mantle and head.

Description

''Eledone gaucha'' possesses a firm, thin, ovoid and elongated mantle. It is separated from the head by a small constriction. The body is smooth and papillae can be found on the dorsal mantle and on the head. The head is narrower than the mantle and the eyes are protruding. The syphon is long, W-shaped and free from its front half. The arms are long and thin. The dorsal arms are notably longer than the other arms and the arms from the males are longer than those of the females.The suckers are small, well separated and deeply anchored in the arms. On the arms of females, suckers are regrouped on the tip of the arm. On the second half of the first right arm, the number of suckers vary between 17 and 23. Males possess heteromorphic arms and some arms with hectocotyl that have modified papillae or suckers. One arm possesses an hectocotyl. The color varies from brown to nearly white dorsally to nearly always white ventrally. Females have a various size ranging from 14 to 55 mm and males range from 14 to 47 mm. The main sources of food for ''E. gaucha'' are microcrustaceans such as

Gammaridae Gammaridae is a family of amphipods. In North America they are included among the folk taxonomic category of " scuds", and otherwise gammarids is usually used as a common name. They have a wide distribution, centered on Eurasia, and are euryha ...

or Caprellidae, of

isopods Isopoda is an Order (biology), order of crustaceans. Members of this group are called isopods and include both Aquatic animal, aquatic species and Terrestrial animal, terrestrial species such as woodlice. All have rigid, segmented exoskeletons ...

and macro crustaceans such as decapods of the orders Brachyura and

Anomura Anomura (sometimes Anomala) is a group of decapod crustaceans, including hermit crabs and others. Although the names of many anomurans include the word ''crab'', all true crabs are in the sister group to the Anomura, the Brachyura (the two groups ...

. The species can also feed on

polychaete Polychaeta () is a paraphyletic class of generally marine Annelid, annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called c ...

s, bony fish and

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

Distribution

''Eledone gaucha'' is found along the coasts of Southern

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

, between Cavo Frio and Chui. For now, it has never been found further south than the coasts of Brazil.

Habitat

''Eledone gaucha'' is found at moderate depth on muddy or sandy soils. During the reproductive period, individuals move to rocky soils overlooking gentle slopes. This habitat is common with '' Eledone massyae''.

Reproduction

Females become sexually mature when they are older and taller than males. They can reproduce when they are not fully mature and store sperm at the apex of ovary filaments. No seasonality in mating could be observed. It is also assumed that cohorts of individuals overlap during the year, each with a reproductive cycle estimated to be sub-annual.

References

{{DEFAULTSORT:Eledone gaucha gaucha Cephalopods described in 1988