Hammer octopus (Octopus australis)

Classification (WoRMS)

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

Accepted name: Octopus australis · Authority: Hoyle, 1885 · Taxonomic status: accepted · AphiaID: 341948.

Synonyms and superseded combinations recorded for this taxon: Robsonella australis (Hoyle, 1885).

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=341948 (CC BY 4.0). Accessed 2026-09-25.

Biology and life history (SeaLifeBase)

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

Habitat zone: benthic.

Source: SeaLifeBase species summary (SpecCode 57270) — https://www.sealifebase.se/summary/Octopus-australis.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-25.

Distribution and occurrence records (GBIF)

183 georeferenced occurrence records for Octopus australis are published through GBIF from 2 countries or marine areas. The map above plots 19 distinct locations from a sample of 183 records, omitting 17 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: Australia (171); New Zealand (12).

Marine regions with a valid WoRMS distribution record: South West Pacific Ocean.

Source: GBIF Occurrence Search (taxonKey 2289511) — https://www.gbif.org/occurrence/search?taxon_key=2289511&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=341948 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-25.

Conservation status (IUCN Red List)

The IUCN Red List assesses Octopus australis Hoyle, 1885 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 163388) — https://www.iucnredlist.org/species/163388/0; GBIF IUCN Red List category endpoint (taxonKey 2289511) — https://api.gbif.org/v1/species/2289511/iucnRedListCategory. Accessed 2026-09-25.

Description and natural history (Wikipedia)

O. australis is medium-sized, with a mature mantle length of around 20 to 25 millimeters for males and 50 to 60 millimeters for females, an arm span of around 40 centimeters, and a maximum total length of 49.9 centimeters. Males weigh around 210 grams and females around 105 grams. The head of O. australis is narrow and egg-shaped and it has small eyes. It is typically a sandy cream color.

O. australis is found in coastal waters and bays along the eastern coast of Australia from central Queensland to southern New South Wales, most commonly in subtropical inshore waters, and from depths of around 3 to 140 meters. It tends to live on sand or mud seafloors, among sponges, ascidians, or mollusks, or in seagrass.

The diet of O. australis is mostly composed of isopods, but they also eat other types of crustaceans, other octopuses, bristle worms, gastropods, and bivalves. They usually forage at night and hide in trash, shells, or the seafloor during the day.

Females lay around 50 to 130 eggs per brood, each egg being about 11 millimeters long. They normally lay eggs in the summer. Eggs take over 100 days to hatch. O. australis have an estimated lifespan of 18 to 20 months.

Source: Wikipedia: Octopus australis — https://en.wikipedia.org/wiki/Octopus_australis (CC BY-SA 4.0). Accessed 2026-09-25.