Veined octopus (Amphioctopus marginatus)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Mollusca · Class: Cephalopoda · Order: Octopoda · Family: Octopodidae · Genus: Amphioctopus.

Accepted name: Amphioctopus marginatus · Authority: (Taki, 1964) · Taxonomic status: accepted · AphiaID: 534099.

Synonyms and superseded combinations recorded for this taxon: Octopus marginatus Taki, 1964; Octopus striolatus Z.-Z. Dong, 1976.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=534099 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (SeaLifeBase)

Measured values published by SeaLifeBase for Amphioctopus marginatus. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 30 cm · Depth range: 0–190 m · Habitat zone: benthic · Vulnerability index: 20 of 100 · Fishery importance: commercial.

SeaLifeBase notes: Its mantle length is 10 cm (Ref. 96968). Found from shallow subtidal to at least 190 meters. Known from coastal muddy waters on mud and substrates. Feeds on crustaceans like crabs Calappa sp., and bivalves. It makes dens in clamshells, coconut shells, bottles and other man-made discarded objects in sand and mud. It will carry one mollusk shell or half a coconut shell while searching for another shell in which to enclose itself (Ref. 96968).

Source: SeaLifeBase species summary (SpecCode 57999) — https://www.sealifebase.se/summary/Amphioctopus-marginatus.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

555 georeferenced occurrence records for Amphioctopus marginatus are published through GBIF from 17 countries or marine areas. The map above plots 60 distinct locations from a sample of 555 records, omitting 23 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: Indonesia (339); Philippines (126); Australia (21); Chinese Taipei (16); China (14); Hong Kong (14); Marshall Islands (4); Papua New Guinea (4); Solomon Islands (4); Japan (3); Malaysia (2); New Caledonia (2); Timor-Leste (2); India (1); Mozambique (1).

Source: GBIF Occurrence Search (taxonKey 5856039) — https://www.gbif.org/occurrence/search?taxon_key=5856039&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=534099 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Amphioctopus marginatus Taki, 1964 as Least Concern (code LC). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 163176) — https://www.iucnredlist.org/species/163176/0; GBIF IUCN Red List category endpoint (taxonKey 5856039) — https://api.gbif.org/v1/species/5856039/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

Amphioctopus marginatus is a species of octopus in the family Octopodidae. The species was first described in 1964 by Japanese malacologist Iwao Taki as Octopus marginatus, and later transferred to the genus Amphioctopus, thus becoming Amphioctopus marginatus. Taki chose the Latin name marginatus (literally margined, from marginum) due to the pale border around the eyes. In 1976, Dong Zhengzhi described the species Octopus striolatus, but this name is not recognized as taxonomically valid.

The main body of the octopus is typically between 5 cm and 10 cm long; including the arms, it can measure up to approximately 30 cm in length. The octopus can weigh up to 400 g. The octopus displays a typical color pattern with dark branching lines similar to veins. The arms are usually dark in color, with contrasting light suckers. In many color displays, a lighter triangular area can be seen immediately below the eye. In 2017, the complete mitochondrial genome of A. marginatus was successfully sequenced, showing the species to be closely related to Amphioctopus aegina.

The species preys predominately on crustaceans such as Calappa crabs, along with bivalves. Eggs are laid in clutches of 100,000 and are 3 mm in length; they are laid as long chains woven together. The female octopus lays eggs within a shelter such as a coconut shell where she will guard and tend to her eggs; like most octopuses, the female coconut octopus will starve to death whilst brooding. Eggs take between 15 and 17 days to hatch and the paralarvae are planktonic.

In March 2005, researchers at the University of California, Berkeley, published an article in Science in which A. marginatus was reported to show bipedal locomotion, or "stilt-walking". This involves rolling two arms to walk while the other six arms are used to disguise itself; the researchers speculated that the disguise might be meant to mimic the appearance of a rolling coconut. According to one of the researchers, Dr Crissy Huffard, octopuses are the only animals without a rigid endo- or exoskeleton who can walk bipedally. This behavior was first observed off the coast of Sulawesi, Indonesia, where coconut shell litter is common. A. marginatus is one of only two octopus species known to display such behavior, the other species being Abdopus aculeatus. In addition to "stilt-walking", A. marginatus also exhibits crawling behaviour typically seen in octopuses.

In 2009, researchers from the Melbourne Museum in Australia observed the coconut octopus using tools for concealment and defense by gathering available debris to create a shelter. The researchers filmed the octopus collecting coconut half-shells from the sea floor that had been discarded by humans. They were then carried up to 20 m and arranged around the body of the octopus to form a spherical hiding place similar to a clamshell. This behavior was observed in specimen in Bali and North Sulawesi, Indonesia, and is likely the first evidence of tool use in invertebrates. Other species of octopus had been observed using shells for hiding, but this was the first case in which shells were prepared and collected for later use, in what the Melbourne Museum has described as "true tool use". Octopuses will often engage in bipedal motion when carrying stacks of debris or items larger than themselves. The coconut octopus has been observed using a variety of materials for shelter, including coconut shells, clamshells, and man-made litter such as bottles.

The coconut octopus is broadly endemic to neritic, tropical waters in the Indian Ocean, Red Sea, Northwest and Western Pacific Ocean, and Southeast Asian Sea. Amphioctopus marginatus is listed as Least Concern on the IUCN's Red List. The primary threat faced by the species is fishing.

The species prefers shallow, subtidal waters along the continental shelf. The species has a maximum depth of 190 m, and can often be found in mud and sand substrates. Large numbers of coconut octopuses can often be found in sandy areas with a higher amount of litter that can be used for shelter.

Source: Wikipedia: Amphioctopus marginatus — https://en.wikipedia.org/wiki/Amphioctopus_marginatus (CC BY-SA 4.0). Accessed 2026-09-23.