Ring-tailed cardinalfish (Ostorhinchus aureus)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Teleostei · Order: Apogoniformes · Family: Apogonidae · Genus: Ostorhinchus.

Accepted name: Ostorhinchus aureus · Authority: (Lacepède, 1802) · Taxonomic status: accepted · AphiaID: 712648.

Synonyms and superseded combinations recorded for this taxon: Amia aurea (Lacepède, 1802); Apogon aureus (Lacepède, 1802); Apogon roseipinnis Cuvier, 1829; Centropomus aureus Lacepède, 1802; Gronovichthys aureus (Lacepède, 1802).

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=712648 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

Measured values published by FishBase for Ostorhinchus aureus. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 14.5 cm · Depth range: 1–40 m · Habitat zone: reef-associated · Body shape: short and / or deep · Vulnerability index: 10 of 100 · Fishery importance: minor commercial · Aquarium trade: commercial.

FishBase notes: Inhabits holes in rocks or under ledges in shallow waters. Known to occur in mixed aggregates with Apogon apogonoides during summer and autumn, but form separate aggregates in winter and spring (Ref. 559 and 637). Forms aggregations (Ref 90102).

Source: FishBase species summary (SpecCode 4837) — https://www.fishbase.se/summary/Ostorhinchus-aureus.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

1,300 georeferenced occurrence records for Ostorhinchus aureus are published through GBIF from 34 countries or marine areas. The map above plots 218 distinct locations from a sample of 1,300 records, omitting 46 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 (450); Philippines (201); Indonesia (182); New Caledonia (112); Fiji (59).

The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.

Source: GBIF Occurrence Search (taxonKey 7193028) — https://www.gbif.org/occurrence/search?taxon_key=7193028&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=712648 (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 Ostorhinchus aureus (Lacepède, 1802) 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 193332) — https://www.iucnredlist.org/species/193332/0; GBIF IUCN Red List category endpoint (taxonKey 7193028) — https://api.gbif.org/v1/species/7193028/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

The French naturalist Philibert Commerson provided the first description of this fish from Réunion in the western Indian Ocean, but it was not published in a format allowing full citation. Therefore, the species name and description by Bernard Germain de Lacépède (who acknowledged Commerson) takes precedence, albeit with a nod to Commerson. With no original or subsequent illustrations or specimens denoted as types, Fricke nominated a neotype in 1999 but subsequently withdrew it.

This species has on occasion been mistakenly considered a junior synonym of the similar species Ostorhinchus fleurieu, but is generally acknowledged as separate; it had the junior species synonym roseipinnis applied by Georges Cuvier in 1829.

Lacépède coined the genus Ostorhinchus in 1802 to which O. aureus was eventually assigned, although he originally placed it in the genus Centropomus which is now placed in a different fish family, Centropomidae.

This fish is coppery-coloured with a broad blackish bar at the base of the tail, up to 14.5 cm in length. The upper jaw has a narrow blue streak, and a broad blackish stripe extends from the front of the snout to the eye. Easily confused with Ostorhinchus fleurieu, where the black tail bar does not narrow in the centre, but unlike this species, the stripe is also present in juveniles.

Internally, O. aureus is one of a large group of nocturnal feeding fishes which has a black pigmented gut lining, apparently to hide the glow of bioluminescent prey from its own piscivores in turn. The eyes of O. aureus allow the transmission of ultraviolet light, which if it is proven to be able to see, could benefit its nocturnal foraging.

Using a shorthand meristics formula, O.

Ostorhinchus aureus inhabits holes in rocks or under ledges in shallow waters. It is known to occur in mixed aggregates with Ostorhinchus apogonoides during summer and autumn, but form separate aggregates in winter and spring.

Whereas coral reef fish settlement tends to be dominated by larval recruitment, in at least part of Australia's Great Barrier Reef, recruitment of O. aureus at any given coral reef patch tends to be by adult and juvenile migration across intervening sand and coral debris.

O. aureus is subject to infection by tiny cnidarian parasites from class Myxosporea. Fish specimens have been found with gall bladder infections of Ceratomyxa apogoni, Ceratomyxa cardinalis, and Ellipsomyxa apogoni. Three species have also been found in skeletal muscle cells: Kudoa cheilodipteri, Kudoa whippsi, and Kudoa iwatai.

O. aureus is a nocturnal predator; where seagrass is adjacent to its reef, it tends to venture out further than some other members of its family.

Studies of stomach content show that O. aureus is a generalist predator, eating mainly planktonic and benthic crustaceans, but, unusually for its family, may at times also eat marine algae.

O. aureus are external bearers, specifically mouthbrooders. Adults tend to pair whilst juveniles tend to aggregate during the day time.

O. aureus is regularly kept by marine aquarists.

Source: Wikipedia: Ring-tailed cardinalfish — https://en.wikipedia.org/wiki/Ring-tailed_cardinalfish (CC BY-SA 4.0). Accessed 2026-09-23.