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Related FAQs: Cardinals 1, Cardinals 2, & FAQs on: Cardinal ID, Cardinal Behavior, Cardinal Compatibility, Cardinal Selection, Cardinal Systems, Cardinal Feeding, Cardinal Disease, Cardinal Reproduction,   Banggai Cardinals, Banggai ID, Banggai Behavior, Banggai Compatibility, Banggai Selection, Banggai Systems, Banggai Feeding, Banggai Disease, Banggai Reproduction,

Related Articles:  Cardinalfishes of Indonesia,

Cardinalfishes Suitable for Small Marine Aquariums 

By Bob Fenner



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     Guess how many Cardinalfish species are described by science… one hundred? Two? According to Fishbase (.org), there are currently some three hundred forty five arrayed in thirty two genera. Though this useful database states that they (sic) “do generally well in aquariums”; some are too large (a few up to 8 in., 20 cm.) or too aggressive to be kept other than solitarily in small volumes. This last includes the most popular, commonly offered species in the trade, the Pajama and Banggais. Most live well enough in groups of solitarily; getting along with other fishes and invertebrates that get along with them.


            As you’ll see here, there are several other suitable, more punctuated offerings that do better in systems of tens of gallons. We’ll do the usual brief run-down on the whole family, list the better choices, and proffer some notes on how to pick out healthy specimens.


Wherefore Cardinalfishes?

Many Cardinalfishes, family Apogonidae ("App-oh-gahn-id-ee")  are reddish in color (hence their common name) mixed with silver and white, though most species are yellow, silvery and black. All have large eyes, and are largely nocturnal; hiding in crevices or beneath ledges by day (typically with Squirrelfishes, Bigeyes and sweepers). These are mostly shallow water fishes, found from the surface to about 100 meters. Some species are found (and should be kept) solitarily; others are definitely schoolers and do far better kept in small groups. We’ll discern twixt as well as mention where species have in recent times been split off into new genera; you will likely find them on the Net, in older references listed under the olde.  

Species of Interest/Use to Aquarists:

Genus Apogon:

Apogon (now Ostorhinchus) aureus (Lacepede 1802), the Ring-Tail Cardinalfish. Indo-Pacific; Red Sea, east Africa to New Caledonia. To nearly five inches in length maximum in the wild. One in Nuka Hiva, Marquesas, Polynesia.  

     Great in a small shoal/group in 30-40 gal.s

Apogon binotatus (Poey 1867), the Barred Cardinalfish. West-Central Atlantic; Florida to Venezuela. To four inches in length. Bonaire pic. A species best kept singly

Apogon (now Nectamia) bandanensis (Bleeker 1854), the Bigeye Cardinalfish. West-Pacific in distribution. To four inches in length. Here are samples of the same species, offering a glimpse of how different each can appear under differing conditions; night/day, or frightened. Below, one at a retail store in Connecticut and, right during a night dive in Fiji. A solo species

Apogon (now Ostorhinchus) compressus (Smith & Radcliffe 1913), the Ochre-Striped Cardinalfish. Western Pacific; Malaysia to Micronesia down to the GBR. To nearly five inches in length. Often found amongst branches of Porites (cylindrica and nigrescens principally). S. Sulawesi pix. A social species

Apogon (now Ostorhinchus) cyanosoma Bleeker 1853, the Yellow-Striped Cardinalfish. Indo-Pacific including the Red Sea. To three inches in length. One off S. Leyte, P.I. Always encountered in a group.

Apogon (now Pristiapogon) fraenatus Valenciennes 1832, the Bridled Cardinalfish (can you make out the bridle?). To four inches in length. Indo-Pacific; from Durban, South Africa to Tuamotus. Image from Fiji at night and Red Sea during the day. Solitary. 

Apogon (now Pristiapogon) kallopterus Bleeker 1856, the Iridescent Cardinalfish. Indo-Pacific, including the Red Sea. To six inches in length. A larger specimen out during the day in the Maldives. Solitary

Apogon (now Zoramia)  leptacanthus (Bleeker 1856-57), Threadfin Cardinalfish. Indo-Pacific including the Red Sea. To a little over two inches in length. Found in dense school in the wild. This group in a friend’s aquarium. A great schooling species for 30-40 plus gallon systems.

Apogon maculatus (Poey 1860), Flamefish. Western Atlantic, Massachusetts to Brazil. To four or so inches in length. Here is one offered for sale. 2-60 feet. Best kept solitarily.

Apogon (now Ostorhinchus) nanus (Allen, Kuiter & Randall 1994). W. Central Pacific. To about 2 in, 5 cm. Here in S. Leyte, P.I. 2013 amongst Diadema setosum spines. A beautiful little schooler

Apogon (now Ostorhinchus) neotes Allen, Kuiter, Randall 1994. Mini Cardinalfish. To 2.7 cm. Western Central Pacific: Maumere Bay (Indonesia), Palau and Madang, Papua New Guinea. Aq. Pic, at friend Rob Bray’s House of Fins, Greenwich, CT.

Apogon (now Ostorhinchus) nigrofasciatus Lachner 1953, the Blackstriped Cardinalfish. Indo-Pacific; Red Sea to the Tuamotus. This one in Fiji. Solitary

Apogon (now Ostorhinchus) sealei (Fowler 1918), Seale's Cardinalfish. Western Pacific; Malaysia to Micronesia. To three inches in length. One in Raja Ampat, Indo. A schooler

Apogon townsendi (Breder 1927), the Barred Cardinalfish. West-Central Atlantic; Florida to Venezuela. To 6.5 cm. in length. Bonaire night pic. Lives solitarily or in groups… often twixt sea urchin spines


Genus Archamia: Not often seen in the trade


Archamia zosterophora (Bleeker 1856) Blackbelted or Girdled Cardinalfish. West Pacific. To 3 in. Here in Raja Ampat.


Genus Cheilodipterus:

Cheilodipterus alleni Gon 1993, Southwestern Pacific; New Guinea, Indonesia. To four inches for males, about 2.5" for females. This one in the area of Gili Air, Lombok, Indonesia. Solitary

Cheilodipterus isostigmus (Schultz 1940), the Dog-Toothed Cardinalfish. West-central Pacific. To nearly four inches in length. This three inch one in Fiji. Best kept one to a tank

Cheilodipterus quinquelineatus Cuvier 1828, the Fivelined Cardinalfish. Indo-Pacific including the Red Sea. To five inches in length. Here is an adult in the Gulf of Aqaba, Red Sea. Solitary when adults


Genus Pseudamia:


Pseudamia amblyuroptera (Bleeker 1856). Indo-West Pacific. To six inches in length maximum; rarely half this in captivity. Not a great beauty, though hardy. Solitary


Genus Pterapogon 


Pterapogon kauderni Koumans 1933, the Banggai Cardinalfish. Restricted in distribution to Banggai Island, Indonesia, though commercially produced in good numbers in Indonesia and elsewhere. To three inches in length. A darling of the ornamental aquatics industry and hobby. Readily reproduced in captivity. Young cluster about large/symbiotic anemones tentacles or the spines of the Urchin Diadema setosum when threatened. In small volumes best kept either solitarily or all females in a group. Adults at right and juveniles below in the wild.


Genus Sphaeremia: Py/ajamafishes.


Sphaeramia nematoptera (Bleeker 1856), the Pajama Cardinalfish. West Pacific. To three inches in length. A long-standing favorite in the aquarium trade. Second perhaps only to the Banggai in use. Can be quarrelsome; I’d keep no more than two-three in a forty gallon

Sphaeramia orbicularis (Cuvier 1828), the Orbiculate Cardinalfish. Indo-Pacific. To four inches in length. An uglier version of the Pajamafish, but hardy just the same. Can live in schools while young, but become argumentative with size.




Cardinals display little middle-ground in their quality on-arrival; they are either hardy and sure to "make it", or thrashed and "doomed" to break down and die. For reference, they share many of the same selection criteria as damselfishes.

1) Behaviorally; look closely at the individuals on display. Schooling ones should be clustered somewhat, with none having "private parties" off in the corners of the system. Are they aware of your presence? Watching your movements? Good.

2) Cut marks and reddening: Examine the bodies of each specimen carefully, especially the insertions of unpaired fins. Do you see evidence of infection on any individual? If so, pass them by.

3) Feeding… the all-time best “acid test”. Always ask that prospective purchases be fed the sorts of foods you’ll employ… in front of you.

4) How long have the fish been on hand? Don’t buy just arrived specimens. The ones that are doomed will perish within a few days of arrival. This being stated, don’t leave them too long at your dealers as they often are starved in the process of collection, holding, shipping… and too thin specimens perish easily.

5) Size matters. Most too-small cardinals don’t make it. Banggai’s are the best example here. None should be moved till they are at least three quarters inch total length. You want to buy juveniles, but not ones that are much younger than sub-adult.


I'd like to mention that Apogonids are an under-rated portion of the living reef's populations. Several of the hundreds of species are of large number in the wild, just not commonly encountered due to their largely nocturnal habits. Many form close associations with invertebrates, living within the spiny shelter of urchins, sea stars and more.


For a really outstanding arrangement, provide a large dark shelter-space with one opening and a group of these fishes and others they are found with in the wild. The under ledge and cover sub-habitat is a rich biotope in the reef world.


Most Cardinalfishes as individuals get along with their own kind, other species of Apogonids and other peaceful tankmates. As noted a few times above; there are species that as adults (breeding size) can, do bicker with their own kind.

Smaller species are strongly promoted for use in fish-only and reef-tank set-ups of only tens of gallons. They are supreme choices, being hardy and interesting; their only shortcomings being that they're shy and reclusive. Apogonids as a rule do not "sample" more than mouth-size invertebrates.

Reproduction, Sexual Differentiation/Growing Your Own:

Several species spawning habits are known. The sexes are not much differentiated but may be distinguished by the males slightly larger size and the girth of gravid females. They are some of the few marine mouthbrooders with the males generally doing the incubating. Young are released after about a week, and develop as plankton for a couple of months in the upper water column.





            As you’ve seen, some Cardinals are far more suitable for small aquarium use than others. My advice is to wait a few months after setting up your new system, to allow it to become stable, give time for live rock organisms to get situated, inoculate the sand bed; add what invertebrates you intend to stock, and then introduce your Cardinals as first fish.


Bibliography/Further Reading:


Allen, G.R & Donaldson, T.J. 2007. Pterapogon kauderni. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2 http://www.iucnredlist.org/apps/redlist/details/63572/0, Environ. Biol. Fish. 57:142.

Dodds, Kieron. 2009. Cardinal Sin: The Plight of the Banggai Cardinalfish Pterapogon kauderni KOUMANS 1933. TFH 1/99. http://www.tfhdigital.com/tfh/200901/#pg95

Hopkins, Steve & Harry Ako and Clyde S. Tamaru. 2005. Manual for the Production of the Banggai Cardinalfish, Pterapogon kaudnerni, in Hawai‘i www.raingarden.us/banggaimanual.pdf

Lunn, K.E. and M.-A. Moreau. 2004. Unmonitored trade in marine ornamental fishes: the case of Indonesia’s Banggai cardinalfish (Pterapogon kauderni). Coral Reefs. 23:344-351.

Marini, F. 1998. Frequently Asked Questions and Answers on Banggai Cardinals. Reef. Org archives. http://www.reefs.org/library/article/f_marini.html.

Marini, F. 1999. Captive care and breeding of the banggai cardinal fish "Pterapogon kaudneri". http://www.reefs.org/library/talklog/f_marini_020799.html

Michael, S. 1996. The Banggai Cardinalfish: A newly available species that may become to popular for its own good. Aquarium Fish Magazine. 8(8):86-87.

Tullock, J. 1999. Banggai cardinalfish alert. Aquarium Frontiers. http://www.aquariumfrontiers.net/EnvironmentalAquarist//html.  

Vagelli, A.A. 1999. The reproductive biology and early ontogeny of the mouthbrooding Banggaai cardinalfish, Petrapogon kauderni (Perciformes, Apogonidae). Environmental Biology of Fishes. 56:79-92.

Vagelli, A.A. 2004. Significant increase in survival of captive-bred juvenile Banggai cardinalfish Pterapogon kaudneri with an essential fatty acid-enriched diet. J. World Aqua. Soc. 35(1):61-69.

Vagelli, A.A. and M.V. Erdmann. 2002. First comprehensive ecological survey of the Banggai cardinalfish, Pterapogon kaudneri. Environ. Biol. Fish. 63:1-8.

Vagelli, A.A. and A. V. Volpedo. 2004. Reproductive ecology of Pterapogon kaudneri, an endemic apogonid from Indonesia with direct development. Environ. Biol. Fish. 70:235-245.

Vagelli, Alejandro. A. 2011. The Banggai Cardinalfish: Natural History, Conservation, and Culture of Pterapogon kauderni. Wiley, ISBN 0470654996


Small Marine Aquariums
Book 1:
Invertebrates, Algae
New Print and eBook on Amazon:
by Robert (Bob) Fenner
Small Marine Aquariums
ook 2:

New Print and eBook on Amazon: by Robert (Bob) Fenner
Small Marine Aquariums
Book 3:

New Print and eBook on Amazon:
by Robert (Bob) Fenner
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