''Robsonella huttoni,'' also known as the club pygmy 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 ...

native to

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

and

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. It was first described in 1943 by William Benham, who named it after Frederick Hutton. As adults they are coloured reddish, orangish and greenish. They reach up to 240mm (9.44 in) in length. They are widespread in New Zealand, but in Australia are only found in the southern regions. They live in tidal and subtidal

reefs A reef is a ridge or shoal of rock, coral, or similar relatively stable material lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic (non-living) processes such as deposition of sand or wave eros ...

from depths of 0 to 386 metres. There are records of them living for up to 250 days, but likely live longer. There is little data on the conservation needs of this species, but it is possible that their distribution will be impacted by

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

Taxonomy and etymology

''Robsonella huttoni'' was first described in 1943 by William Benham as ''Octopus huttoni'' from specimens collected in the

Otago Otago (, ; ) is a regions of New Zealand, region of New Zealand located in the southern half of the South Island and administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local go ...

region of

. The specific name refers to Frederick Hutton, who described the first species of octopus in New Zealand ('' Macroctopus maorum''). It was most recently redescribed in 1999 by

Steve O'Shea Steve O'Shea (born 14 December 1965 in Auckland, New Zealand) is a Marine biology, marine biologist and environmentalist known for his research on giant squid. O'Shea obtained his degrees from Auckland university. He undertook a Bachelor of Sci ...

. In 2020, on the basis of genetic data, it was moved to the '' Robsonella'' genus. They are sometimes commonly referred to as "club pygmy octopus".

Description

The adults of this species are known to reach up to 240mm (9.44 in) in length. The mantle is about 57mm (2.24 in) long. When they are alive, they vary in colour, having been seen in reddish, orangish and greenish colour patterns. The head is strong developed with the surface being papillose (being covered in

papilla Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Papilla (worms), small bumps on the surface of certain worms * Basilar papilla, a sensory organ of lizards, amphibians and fish * ...

). Each of the papilla are small and rounded. There are also one to two occular cirri (hair like appendages just above the eyes). Like the head, the arms are also papillose. When the octopus is an adult, the tenth to thirteenth suckers are notably enlarged. The third arm of the male is

hectocotylised A hectocotylus (: hectocotyli) is one of the cephalopod limb, 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 ma ...

(modified to store and transfer

spermatophores A spermatophore, from Ancient Greek σπέρμα (''spérma''), meaning "seed", and -φόρος (''-phóros''), meaning "bearing", or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especially ...

). This arm has around 69 to 74 suckers. There are usually seven

gill lamellae Lamellae on a gecko's foot. In surface anatomy, a lamella is a thin plate-like structure, often one amongst many lamellae very close to one another, with open space between. Aside from respiratory organs such as book lungs, they appear in other ...

, but six and eight lamellae are known to occur.

Larvae

After hatching, the

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e are roughly 3mm (0.118 in) long and 1.55mm (0.061 in) in width. The larvae have large eyes and semitransparent in colour. The body is covered in Kölliker’s organs, which look like small iridescent spots.

Eggs

Each egg is coloured white and is 2.5mm (0.098 in) long and 1mm (0.039 in) in width. The eggs are linked to each other by strands that are up to 25.8mm (1.015 in) long.

Distribution and habitat

This species is native to

and

. They occur throughout New Zealand, including the subantarctic islands except for Campbell Island (and only larval specimens have been collected in

Macquarie Island Macquarie Island is a subantarctic island in the south-western Pacific Ocean, about halfway between New Zealand and Antarctica. It has been governed as a part of Tasmania, Australia, since 1880. It became a Protected areas of Tasmania, Tasmania ...

). In Australia, they are only known from the

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

and southern Australia. They are shallow species, occurring from 0-386 metres in depth. Their typical habitat includes intertidal and subtidal reefs.

Life history

Unlike many other species of octopus, ''Robsonella huttoni'' has a planktonic paralavae stage. One study found that near shore populations had older individuals whereas further offshore populations had younger ones. It was suggested that this is evidence the species demonstrates an

ontogenetic niche shift Ontogenetic niche shift (abbreviated ONS) is an ecological phenomenon where an organism (usually an animal) changes its diet or habitat during its ontogeny (development). During the ontogenetic niche shifting an ecological niche of an individual c ...

(where a species has different diet or habitat requirements at different life stages). In this case, it was speculated that the planktonic paralarva are transported further offshore by currents, but eventually migrate further inshore as they mature. This species has been recorded living up to 250 days, although this is likely to be an underestimation.

Conservation status

As of 2018, ''Robsonella huttoni'' is listed as "Data Deficient" by the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

. One study has suggested that the larval stages of this species are negatively affected by temperatures of over 23 °C. Because of this, it is possible that changes in ocean temperature due to

will limit the distribution of this species.

References

External links

CephRef: ''Robsonella huttoni''
{{Taxonbar, from=Q2164025 Cephalopods of Oceania Octopodidae Molluscs described in 1943 Molluscs of New Zealand Molluscs of the Pacific Ocean