Ring-Tailed Cardinalfish (Ostorhinchus aureus, O. fleurieu) of the Eastern Hemisphere

by DerdriuMarriner

There are two kinds of ring-tailed cardinalfish. One can be said to be born and die with a ringed tail. The other gets a ringed tail as a rite of passage into adulthood.

Bright colors in exotic locales act as aesthetic and directional attention-getters when it comes to official, private and public buildings.

Garish blues, pinks and yellows beautifully and unequivocally announce the physical locations of businesses, homes, and offices. At the same time strong blues, reds and yellows blend wildlife and wildscapes in the exotic subtropics and tropics. Vivid colors in fact camouflage animals in vividly colored environments. So they contribute to the overall impression that wildlife makes upon human admirers and predators.

For example, the ring-tailed cardinalfish owes its name to a band that is blackened to blend with the marine play of light and shadow and a body whose redness recalls a Christian cardinal's vibrant robes.

Blizzard Ridge, Exmouth, North West Cape, Western Australia state, northwestern Australia
Blizzard Ridge, Exmouth, North West Cape, Western Australia state, northwestern Australia


The name ring-tailed cardinalfish applies to two different -- but similar-looking -- fish. The flower cardinalfish carries the scientific name Ostorhinchus fleurieu and the common names bullseye, gold, ring-tail, and ring-tailed cardinalfish. The golden cardinalfish has the scientific name Ostorhinchus aureus and the common names band-tail, golden, ring-tail, and ring-tailed cardinalfish. Both species occupy their respective places within the scientific taxonomic system of binomial, Greek/Latin nomenclature thanks to the industriousness of Agen-born French naturalist Bernard Germain Étienne de la Ville-sur-Illon, comte de Lacépède (December 26, 1756 – October 6, 1825) in 1802 regarding tropical fishes. They owe overlapping common designations to the non-scientific taxonomic system of trivial, vernacular names whose expression recognizes distinct colors and memorable patterns.


Flower and golden ring-tails appear bronze-, copper-, or orange-colored above, gold-colored below, and pale-colored behind. A broad stripe blackens the left and right profile views from the tip of the cardinalfish’s snout to the eye and diffuses beyond the left and right orbits. Iridescent, narrow blue streaks embellish each maxilla (upper jaw) in profile. A broad black bar encircles the caudal peduncle (tail base). It explains the designation of the two species as ring-tails. It is present as an hourglass with defined edges throughout the juvenile and mature stages of the golden ring-tail. It succeeds a black “bull’s-eye” spot of the juvenile stage in the flower ring-tail. It transforms into the mature flower ring-tail’s diffusely-edged, straight-lined band.


illustration by Philibert Commerçon (November 18, 1727 – March 13, 1773):

labelled as Ostorhinchus fleurieu in 3rd volume of history of fishes by comte de Lacépède (December 26, 1756–October 6, 1825), whose descriptions were based on Commerçon's papers, which were given to the Count in disarray.
Bernard Germain de Lacépède, Histoire Naturelle des Poissons (1801), tome III, Plate 32, opp. p. 523
Bernard Germain de Lacépède, Histoire Naturelle des Poissons (1801), tome III, Plate 32, opp. p. 523


The ring-tailed cardinalfish belongs to the Apogonidae family of perch-like, ray-finned fishes of the Atlantic, Indian, Mediterranean, and Pacific Oceans. Ring-tails have big-eyed, large-headed elongated bodies with:

  • Gill rakers (19 – 23 fleurieu, 22 – 27 aureus);
  • Posterior and ventral (lower) margins serrate (tooth-like);
  • Preopercular ridge smooth before the gill cover;
  • Rays (anal fin II[8], anal soft 8, dorsal fin VII-I[9], dorsal soft 9, pectoral fin 14, pelvic fin I[5]);
  • Scales (circumpeduncular 12, median predorsal 5, predorsal 5, pored lateral line 25);
  • Spines (anal 2, dorsal 8);
  • Vertebrae (24).

They mature to total lengths of 3.9 – 5.9 inches (10 – 15 centimeters). Lower ranges reflect the typical size of the adult female whereas upper ranges represent that of adult males.


A large, oblique mouth constitutes one of the most noticeable features of the flower and the golden ring-tailed cardinalfishes. It functions as a food-trapper for both females and males. In the wild and after a 30-minute “quiet time” following sunset, ring-tails make daily forays for:

  • Benthic crustaceans;
  • Mobile invertebrates;
  • Small fish;
  • Zooplankton.

In captivity, they may be trained to consume:

  • Fresh and frozen meaty foods;
  • Small fish;
  • Small shrimp.

They must avoid:

  • Dry processed foods;
  • Flakes;
  • Pellets.

They survive 2 – 3 years in 30+-U.S. gallon (113.6+-liter) aquaria which:

  • Include dark niches;
  • Lack large predators;
  • Standardize hardness (8 - 12°d), pH (8.2 - 8.5), sg (1.020 - 1.025), stocking (1 male for every 2 females), and temperatures (72 - 78°F [22.2 - 25.6°C]).


Ring-tailed cardinalfish (right) with five-lined cardinalfish (Cheilodipterus quinquelineatus)

marina, Wakaya Island, Fiji's Lomaiviti Archipelago, Koro Sea
marina, Wakaya Island, Fiji's Lomaiviti Archipelago, Koro Sea


The super-mouths of Apogonidae family members additionally act to ensure future generations. They definitely assume that role in the life cycle of the sexually mature flower and golden ring-tailed cardinalfish … males! Flower and golden cardinalfish females continue in their roles as egg-makers. They deposit egg masses near the fathers-to-be. The males fertilize the eggs. The 0.1-inch (0.25-centimeter), large-yolked eggs get vacuumed into the paternal mouth. They hatch several weeks later. The male is so committed to guarding and hatching his brood that foraging ceases. He makes up for his self-imposed fasting by bulking up before and after year-round brood-ability, which nevertheless peaks in summer. Ring-tails tend to avoid egg mortality and -- every 15 months -- double populations.


The ring-tailed young become members of dark worlds. Darkness determines the ring-tails’ spatial and temporal life cycles. During the day, flower and golden ring-tails dwell in darkened, inaccessible, predator-proof spaces:

  • Among branching coral;
  • In rocky crevices;
  • Under shallow ledges.

With nightfall, they emerge to forage and foray in schools whose adult members couple up for:

  • Cavorting;
  • Courting;
  • Sheltering;
  • Spawning.

Their schools form super-aggregations with short-tooth cardinalfishes (Ostorhinchus apogonoides) every summer and autumn. Ring-tailed schools go back to same-species exclusiveness every winter and spring. But whether they are in aggregation- or school-mode, flower and golden ring-tails limit themselves to navigating moderate currents at respective depths of:

  • 3.3 – 98.4 feet (1 – 30 meters);
  • 3.3 – 131.2 feet (1 – 40 meters).


ring-tailed cardinalfish at Ningaloo Reef, UNESCO World Heritage Site in Western Australia state, northwestern Australia

"Taken by Craig (Our DM [Dive Master] for our dive at Ningaloo."
"Taken by Craig (Our DM [Dive Master] for our dive at Ningaloo."

Conclusion: Thriving in exotic locales as well as in aquaria


In the Eastern marine “wild” of latitudes 30°N - 30°S, both ring-tails circle:

  • Bays, estuaries, lagoons;
  • Coral and ocean reefs;
  • Indian and Pacific seashores (Australia, East Africa, Hong Kong);
  • Islands (Indonesia, Philippines, Seychelles, Sri Lanka).

Flower ring-tails circle:

  • Andaman and Red Seas;
  • Fiji;
  • India;
  • Malaysia;
  • Oman and Persian Gulfs.

Golden ring-tails circle:

  • Christmas Island;
  • Comoros, Madagascar, and Mauritius;
  • Japan;
  • New Caledonia, Papua/New Guinea, Reunion, Tonga, and Vanuatu;
  • Taiwan.

Scientists consider flower cardinalfish more numerous than golden ring-tails. Private and public aquaria owners generally decide in favor of the “friendlier” golden cardinalfish. But non-scientists and scientists jointly deem both ring-tails:

  • Harmless water quality indicators in captive- and wild-scapes;
  • Hearty adapters to aquarium-scapes;
  • Robust survivors of precarious, protected marine-scapes.


Flower ring-tail cardinalfish

Pulau Aur, Seribuat Archipelago, off southeast coast of West Malaysia
Pulau Aur, Seribuat Archipelago, off southeast coast of West Malaysia



My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.


Red Sea: habitat of anklet cardinalfish (Apogon pselion), which are not called ringed-tail even though they may be confused with flower and golden ring-tails.

The Randall/Fraser/Lachner discovery team in 1990 identifes as unique to the anklet cardinalfish 19 - 22 gill rakers, Red Sea habitat, smaller size, and yellow stripes (4 per left/right head profiles, 1 per left/right body side views).
Red Sea forks into Gulf of Suez to west (left) of Sinai Peninsula and Gulf of Aqaba to east (right).
Red Sea forks into Gulf of Suez to west (left) of Sinai Peninsula and Gulf of Aqaba to east (right).

Sources Consulted


Allen, G.R. 1998. “A New Species of Cardinalfish (Apogonidae) from the Komodo Islands, Indonesia.” Revue Française d’Aquariologie, Vol. 25, No. 1-2: 27-30.

"Apogon aureus: Golden Cardinalfish." ZipcodeZoo. Retrieved on February 17, 2014.

  • Available at: http://zipcodezoo.com/Animals/A/Apogon_aureus/

"Apogon fleurieu: Bandtail Cardinalfish." ZipcodeZoo. Retrieved on February 17, 2014.

  • Available at: http://zipcodezoo.com/animals/a/apogon_fleurieu/

"Apogon pselion (臂飾天竺鯛)." ZipcodeZoo. Retrieved on February 17, 2014.

  • Available at: http://zipcodezoo.com/Animals/A/Apogon_pselion/

"Apogon pselion Randall, Fraser & Lachner 1990." Fishwise Universal Fish Catalogue Species Detail Page. Retrieved on February 17, 2014.

  • Available at: http://www.fishwise.co.za/Default.aspx?TabID=110&SpecieConfigId=249272&GenusSpecies=Apogon_pselion

Bunch, Bryan. 1995. "Cardinalfish." P. 10 in Amazing Animals of the World, Vol. 6: Cape Pangolin - Common Buzzard. Grolier Educational Corporation.

Capuli, Estelita Emily; and Luna, Susan M. "Apogon pselion Randall & Fraser & Lachner." FishBase. Retrieved on February 17, 2014.

  • Available at: http://fishbase.org/summary/4839

Capuli, Estelita Emily; and Valdestamon, Roxanne Rei. "Ostorhinchus aureus (Lacepède, 1802): Ring-tailed Cardinalfish." FishBase. Retrieved on February 17, 2014.

  • Available at: http://www.fishbase.org/summary/4837

Capuli, Estelia Emily; and Valdestamon, Roxanne Rei. "Ostorhinchus fleurieu Lacepède, 1802: Cardinalfish." FishBase. Retrieved on February 17, 2014.

  • Available at: http://www.fishbase.org/summary/Ostorhinchus-fleurieu.html

Dawes, John. 2005. "Cardinalfish." Pp. 30-31 in World of Animals, Vol. 40 Spiny-finned Fish 2: Bass, Cichlids, Damselfish, Barracudas. Danbury, CT: Grolier imprint of Scholastic Library Publishing.

de Lacépède, Bernard Germain. Histoire Naturelle des Poissons. Tome III. Paris: l'Imprimerie de Plassan, [1801].

  • Available via Internet Archive at: https://archive.org/details/histoirenaturell06lac

de Lacépède, Bernard Germain. Histoire Naturelle des Poissons. Tome IV. Paris: l'Imprimerie de Plassan, l'An X de la République [1802].

  • Available via Internet Archive at: https://archive.org/details/histoirenaturell04lacs

Fricke, R.; and Gon, O. 2010. “Apogon fleurieu.” In: IUCN 2013. IUCN Red List of Threatened Species Version 2013.2. Retrieved on February 17, 2014.

  • Available at: http://www.iucnredlist.org/details/154912/0

Gon, Ofer. "Redescription of Apogon (Ostorhinchus) fleurieu (Lacépède, 1802) with Notes on its Synonymy." Japanese Journal of Ichthyology, Vol. 34, No. 2 (1987-1988): 138-145.

  • Available via J-Stage at: https://www.jstage.jst.go.jp/article/jji1950/34/2/34_2_138/_article
  • Available at: www.wdc-jp.biz/pdf_store/isj/publication/pdf/34/342/34204.pdf‎

Randall, John E.; Fraser, Thomas H.; and Lachner, Ernest A. 1990. "On the Validity of the Indo-Pacific Cardinalfishes Apogon aureus (Lacepède) and A. fleurieu (Lacepède), with Description of a Related New Species from the Red Sea." Proceedings of the Biological Society of Washington, Vol. 103, No. 1: 39-62. Retrieved on February 17, 2014.

  • Available via Internet Archive at: https://archive.org/details/proceedingsofb1031990biol

"Ring-Tailed Cardinalfish." Florent's Guide to the Tropical Reefs. Retrieved on February 17, 2014.

  • Available at: http://reefguide.org/ringtailedcardinalfish.html

"Ring-tailed Cardinalfish: Apogon aureus." Aquatic Community. Retrieved on February 17, 2014.

  • Available at: http://www.aquaticcommunity.com/marinefish/ringtailedcardinalfish.php

"Ring-tailed Cardinalfish: Apogon aureus." Oceana Marine Wildlife Marine Animal Encyclopedia. Retrieved on February 17, 2014.

  • Available at: http://oceana.org/en/explore/marine-wildlife/ring-tailed-cardinalfish


Golden ring-tails thrive in the waters around the Australian Territory of Christmas Island.

Christmas Island, Australian territory in eastern Indian Ocean
Christmas Island, Australian territory in eastern Indian Ocean
the end which is also the beginning
the end which is also the beginning

Ring-Tailed Cardinalfish, Papua, New Guinea: photo by Valerie and Ron Taylor

30 x 20 Print. High quality RA4 prints. Printed on Kodak Endura and Edge papers. Estimated image size 762x508mm.
Photographic Print of Ring-tailed cardinalfish - Ardea Wildlife Pets

Jigsaw Puzzle of Valerie and Ron Taylor's photo of Ring-Tailed Cardinalfish

10x14 Photo Puzzle with 252 pieces. Packed in black cardboard box 5 5/8 x 7 5/8 x 1 1/5. Puzzle image 5x7 affixed to box top.
Photo Jigsaw Puzzle of Ring-tailed cardinalfish - Ardea Wildlife Pets

Ring-tailed Cardinal Fish: photo by Matthew Oldfield

Ring-tailed Cardinal Fish

Me and my purrfectly purrfect Maine coon kittycat, Augusta "Gusty" Sunshine

Gusty and I thank you for reading this article and hope that our product selection interests you; Gusty Gus receives favorite treats from my commissions.
DerdriuMarriner, All Rights Reserved
DerdriuMarriner, All Rights Reserved
Updated: 08/02/2021, DerdriuMarriner
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