Chestnut octopus (Octopus conispadiceus)
Source-cited species reference: taxonomy from WoRMS, biology from SeaLifeBase, occurrence map from GBIF, conservation from IUCN Red List, description from Wikipedia.
Last updated
A. C. Tatarinov · via Wikipedia: Octopus conispadiceus · CC0
Octopus conispadiceus (commonly the chestnut octopus) is a species of long-ligula octopus, provisionally placed in the genus Octopus. It was first described by Madoka Sasaki in 1917 based on specimens bought at a fish market in Sapporo, Japan.
Scientific classification
- OrderOctopoda
- FamilyOctopodidae
- GenusOctopus
- SpeciesOctopus conispadiceus
Named by Sasaki, 1917
Close relatives
Other species of Octopus with a Codexery entry.
- Hawaiian octopus Octopus hawaiiensis
- Hubb's octopus Octopus hubbsorum
- Mexican four-eyed octopus Octopus maya
- Octopus australis Octopus australis
- Octopus bocki
- Octopus chierchiae
- Octopus cyanea
- Octopus mimus
Sources: Wikipedia taxobox: Octopus conispadiceus (CC BY-SA 4.0) · order, family and genus agree with WoRMS AphiaID 341963 (CC BY 4.0)
Conservation status
Least Concern (LC)
- LC▲ this species
- NT
- VU
- EN
- CR
- EW
- EX
Source: IUCN Red List assessment · GBIF copy of the Red List category
How big is it?
Largest length in the source, 1.5 m, next to a 1.8 m person.
Diagram: drawn by Codexery, schematic shapes to scale (not a likeness). Length: SeaLifeBase species summary
Where the chestnut octopus (octopus conispadiceus) has been recorded
Each dot is a place where the species has been observed and reported (315 records, half-degree grid) — not a modelled range. 2 inland records left out (institution coordinates).
Map: drawn by Codexery. Data: GBIF occurrence search (records CC0 / CC BY) · Natural Earth basemap (public domain) · place coordinates: Wikipedia (CC BY-SA 4.0)
Classification (WoRMS)
Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Mollusca · Class: Cephalopoda · Order: Octopoda · Family: Octopodidae · Genus: Octopus.
Accepted name: Octopus conispadiceus · Authority: (M. Sasaki, 1917) · Taxonomic status: accepted · AphiaID: 341963.
Synonyms and superseded combinations recorded for this taxon: Paroctopus conispadiceus (M. Sasaki, 1917); Polypus conispadiceus M. Sasaki, 1917.
Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=341963 (CC BY 4.0). Accessed 2026-09-25.
Biology and life history (SeaLifeBase)
Measured values published by SeaLifeBase for Octopus conispadiceus. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.
Maximum length: 150 cm · Habitat zone: benthic · Vulnerability index: 90 of 100 · Fishery importance: commercial.
SeaLifeBase notes: Also caught by bottom longline. Females grow larger than males (Ref. 3722).
Source: SeaLifeBase species summary (SpecCode 57444) — https://www.sealifebase.se/summary/Octopus-conispadiceus.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-25.
Distribution and occurrence records (GBIF)
315 georeferenced occurrence records for Octopus conispadiceus are published through GBIF from 3 countries or marine areas. The map above plots 6 distinct locations from a sample of 315 records, omitting 2 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: Japan (311); Korea, Republic of (2); Russian Federation (2).
Marine regions with a valid WoRMS distribution record: West North Pacific.
Source: GBIF Occurrence Search (taxonKey 2289646) — https://www.gbif.org/occurrence/search?taxon_key=2289646&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=341963 (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 conispadiceus (Sasaki, 1917) 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 163397_1) — https://www.iucnredlist.org/species/163397_1/0; GBIF IUCN Red List category endpoint (taxonKey 2289646) — https://api.gbif.org/v1/species/2289646/iucnRedListCategory. Accessed 2026-09-25.
Description and natural history (Wikipedia)
O. conispadiceus is large, with a mantle length of up to 210 millimeters and a total length of at least 120 centimeters; its arms are moderate in length, around three times the length of the mantle. There are 140 to 150 suckers on each arm in males and 170 to 190 in females, and suckers are larger in males than females.
O. conispadiceus is firm and muscular, with smooth skin, and light gray-blue in color with a white line across its head. It has seven rows of teeth and an ink sac. O. conispadiceus has small eyes.
O. conispadiceus is found in cold temperate waters off northern Japan and the Kuril Islands. It is a benthic shelf species, living from depths of around 50 to 100 meters, mostly in sandy or muddy substrates.
O. conispadiceus reaches maturity quickly, around 10 to 11 months in cold waters. Juveniles look much like adults, but have a different skin texture.
The species has a short life span, with estimates between under two years and three to four years. Females lay from 400 up to 1,200 eggs at a time; the eggs are very large, up to 28 millimeters. The size of the eggs suggests that hatchlings are benthic.
O. conispadiceus is fished commercially in Japan. It is the second most common species of octopus in fish markets in Hokkaido, and is sometimes bycatch in gillnet fishing, especially in Russia
Source: Wikipedia: Octopus conispadiceus — https://en.wikipedia.org/wiki/Octopus_conispadiceus (CC BY-SA 4.0). Accessed 2026-09-25.
Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Octopus conispadiceus (CC BY-SA 4.0).
- Classification: the source article's taxobox; order, family and genus checked against WoRMS, the World Register of Marine Species (CC BY 4.0).
- Conservation status: IUCN Red List assessment.
- Occurrence records: GBIF (CC0 / CC BY). Basemap: Natural Earth (public domain).
- Biology values: SeaLifeBase species summary (CC BY-NC 3.0, non-commercial).
- Word definitions: the , each quoted from its Wikipedia article.
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