Orange cookie star (Ceramaster patagonicus)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Echinodermata · Class: Asteroidea · Order: Valvatida · Family: Goniasteridae · Genus: Ceramaster.

Accepted name: Ceramaster patagonicus · Authority: (Sladen, 1889) · Taxonomic status: accepted · AphiaID: 213335.

Synonyms and superseded combinations recorded for this taxon: Ceramaster grenadensis patagonicus (Sladen, 1889); Ceramaster lennoxkingi McKnight, 1973; Mediaster patagonicus (Sladen, 1889); Pentagonaster austrogranularis Perrier, 1891; Pentagonaster patagonicus Sladen, 1889.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=213335 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (SeaLifeBase)

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

Maximum length: 20 cm · Depth range: 10–245 m · Habitat zone: benthic · Vulnerability index: 10 of 100.

SeaLifeBase notes: Found on rocks or mud (Ref. 93256), in subtidal areas to a depth of 235 meters (Ref. 865).

Source: SeaLifeBase species summary (SpecCode 49286) — https://www.sealifebase.se/summary/Ceramaster-patagonicus.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

965 georeferenced occurrence records for Ceramaster patagonicus are published through GBIF from 16 countries or marine areas. The map above plots 410 distinct locations from a sample of 965 records, omitting 27 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: New Zealand (408); Canada (248); United States of America (116); South Africa (41); Antarctica (32); Chile (30); Falkland Islands (Malvinas) (18); French Southern Territories (18); Argentina (15); Australia (12); Congo, Democratic Republic of the (6); Russian Federation (5); Mexico (4); Costa Rica (3); Ecuador (2).

Marine regions with a valid WoRMS distribution record: South Argentina; Campbell Plateau; New Zealand Exclusive Economic Zone; South Chile; Macquarie Island Exclusive Economic Zone; Overlapping claim Falkland / Malvinas Islands: United Kingdom / Argentina part of the South Atlantic Ocean; Scotia Sea; Antarctic Peninsula; Amundsen Sea; Marion-Prince Edward Is.; Crozet Islands part of the Indian Ocean; South Pacific Abyssal Province.

Source: GBIF Occurrence Search (taxonKey 2271610) — https://www.gbif.org/occurrence/search?taxon_key=2271610&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=213335 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Description and natural history (Wikipedia)

The World Register of Marine Species lists four subspecies:

Ceramaster patagonicus euryplax H.L.

The cookie star is roughly pentagonal in shape with a diameter of up to 16 cm. It has a slightly inflated, broad central disc and five short rays. The aboral (upper) surface is covered with neatly arranged flat-topped scales, polygonal in the central area and hexagonal on the rays. Between the rays the scales are small and crowded together. There is a marginal row of distinctive larger scales forming a bevelled edge. Sometimes the disc and ray areas are swollen with sunken inter-radial areas between. This may happen when the starfish has recently fed or when its gonads are enlarged prior to spawning. The general colour is yellow, orange or pink. It is larger than the rather similar Arctic cookie star (Ceramaster arcticus) and does not have red patches on the aboral surface as that species often has.

The cookie star is found in the Southern Ocean, the Strait of Magellan and in Australian and New Zealand waters. It is also found on the west coast of North and South America from Alaska southwards to Cape Horn. It is a deep water species, in the Southern Ocean being found at depths varying between 100 and 5000 m but is commonest at depths less than 250 m.

The cookie star feeds on sponges such as the cloud sponge (Aphrocallistes vastus) and the chocolate puffball sponge (Latrunculia austini). The Morning sun star (Solaster dawsoni) is a predatory starfish that feeds on other starfish. If approached by a morning sun star, a cookie star does not attempt to flee, although this would be a pointless strategy as the cookie star is a very slow crawler. The morning sun star climbs on top in its usual attacking position but soon gives up and looks very sick, apparently repelled by a toxic chemical substance. In an experiment, four cookie stars were kept in a tank with a number of hungry morning sun stars for a period of two months, but none were harmed.

Source: Wikipedia: Ceramaster patagonicus — https://en.wikipedia.org/wiki/Ceramaster_patagonicus (CC BY-SA 4.0). Accessed 2026-09-23.