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Damsels & Clownfishes:
Some Not-Too Feisty Choices for Nanos

By Bob Fenner

Available here
Small Marine Aquariums
Book 1:
Invertebrates, Algae
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Small Marine Aquariums
ook 2:

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

Even the most unfamiliar person recognizes "Nemo" and other Clownfishes as such on encountering them in aquariums or underwater on tropical reefs. Similarly, their closely related cousins, the often-feisty Damselfishes are easily noted as marines. Though they comprise a large (some 350 described species and counting) assemblage of mostly smallish fishes, only a few are good choices for small/er system stocking. Most are too agonistic/aggressive to fit in with other fish and some non-fish tankmates; several only live well and long in a shoaling situation, requiring a larger volume/world. Others either grow too large or just can't handle the stress of small confines. Thankfully, there are a few genera of damsels and a couple clown species that do quite well in "Nano" size systems. These and their basic husbandry is the subject of this article.

Basic Biology:

The family Pomacentridae, Damselfishes, (subfamily Chrominae) and the Clownfishes (subfamily Amphiprionae) are important reef fishes on a few counts. They are found everywhere on tropical shallow water environs where there is sufficient cover and forage, providing micro-algal cleaning (even culture in some cases) services, functioning as food items for larger predators, and act significantly in determining the livestock make-up of their well-defined lek & feeding territories.

For us as marine aquarists, several of the Pomacentrids factor as key captive choices, for their hardiness, beauty, and interesting behaviours. Of the dozen or so commonly kept species, all are generally "reef safe", tolerant of wide/r and varying chemical and physical water quality, typically disease-resistant, and accepting of all types of prepared commercial foods.

Best Species for Small System Use:

Genus Acanthochromis: Monotypic/one species.

Acanthochromis polyacanthus (Bleeker 1855), the Spiny Chromis (only member of the genus). Indo-Australian; inshore and off-shore reefs. Notably the only species of Pomacentrid that instead of having pelagic larval development, spawns, rears its young cichlid-fashion. Australian images of a parent and young.ã''

Genus Chrysiptera:

Chrysiptera bleekeri (Fowler & Bean 1928), Bleeker's Damsel. Western Central Pacific; Timor, Flores (and this report of Lombok), Indonesia and theã''Philippines. To about three inches in length. Photo made off N. Sulawesi, Indonesia.ã''


Chrysiptera cyanea (Quoy & Gaimard 1825), the Blue Devil/Damsel. Likely the most commonly used member of the Damsel family by the aquarium interest. Western Pacific over to the bare eastern edge of the Indian Ocean. Toã''two and a half inches in length. Females with a dark spot/band over their nose, males have orange yellow on fins.


Chrysiptera galba Allen & Randall 1974, the Canary Demoiselle. South Central Pacific. To two and a half inches in length. A beauty that should be imported more frequently.


Chrysiptera hemicyanea (Weber 1913), the Azure Demoiselle. 7 cm.. Indo-West Pacific; Eastern Indian Ocean, Indonesia. Aquarium image.ã''


Chrysiptera parasema (Fowler 1918), the Yellow-Tail Blue Damsel. Contending for first place as "most used member of the family of Damselfishes". From the western Pacific. To two and a half inches.ã'' Hardy and relatively easygoing.


Chrysiptera rollandi (Whitley 1961), Rolland's Demoiselle. Indo-Australia Archipelago. To a mere one and three quarters inch in length. In Raja Ampat, Malaysia, and N. Sulawesi.ã''


Chrysiptera starcki (Allen 1973), Starck's Demoiselle. Western Pacific; Noumea to Queensland to Japan. To nearly two and a half inches. A beautiful reef-associated Damsel, best kept one to a tank.


Chrysiptera talboti (Allen 1975), Talbot's Damsel. Indo-West Pacific. To about two inches maximum length. A great little Damsel for reef aquariums. Regularly collected for the ornamental trade in Fiji.


Chrysiptera taupou (Jordan & Seale 1906), the Village Belle or South Seas Devil. Southwestern Pacific Ocean. A great beauty and relatively non-aggressive. A very nice addition as an individual specimen to reef aquariums; where this one was photographed. To two and a half inches in length.


Chrysiptera unimaculata (Cuvier 1830), the One spot Demoiselle. Indo-west Pacific, Red Sea. Highly variable in markings, color, from east coast of Africa to Fiji. This juvenile and sub-adult in the Maldives. To three inches overall in length. Imported as juveniles that turn overall brownish with age.


Genus Pomacentrus: The fifty six described species of this Damsel genus contain many peaceful aquarium possibilities. I list a few of the more commonly available here.

Pomacentrus alleniã''Burgess 1981, Allen's or Andaman Damselfish. Andaman Sea, the Similans off of Thailand. A hardy beauty that grows to a maximum of two inches and does well living solitarily. This one in a reef aquarium by itself.


Pomacentrus auriventris Allen 1991, the Yellow-belly or Goldbelly Damsel. Indo-Malay Peninsula, Caroline Islands. To 5.5 cm. Found near bottom, principally about rubble slopes. N. Sulawesi pix.ã''


Pomacentrus bankanensis Bleeker 1853, the Speckled Damsel. Western Pacific; Christmas Island to Fiji, North to S. Japan, S. to Noumea. To 9 cm. Lives amongst bottom rubble, feeds on algae, copepods, isopods, pelagic tunicates. Juvenile in Raja Ampat, adult in N. Sulawesi.


Pomacentrus caeruleus Quoy & Gaimard 1825, the Caerulean Damsel. Western Indian Ocean, eastern Africa to the Maldives. To four inches maximum. A Damselfish beauty that deserves to be imported much more frequently. This one in the Maldives.


Pomacentrus sulfureus Klunzinger 1871, the Sulphur Damsel. Western Indian Ocean, including the Red Sea. To three inches overall length. This fish has become a steady offering in the pet trade. It's a gorgeous golden yellow overall as an adult and only slightly less so as juveniles.


Pomacentrus vaiuli Jordan & Seale 1906, the Ocellated Damselfish. Western Pacific to Eastern Indian Ocean. To four inches in length, and as territorial as the genus comes... hangs out on its patch of Acroporid coral in the wild, and best kept this way with plenty of room (at least twenty gallons to each) in captivity. Color variable, some with a yellowish dorsal region grading to blue. Juvenile in Fiji shown.


Clownfishes: Ocellaris and Perculas. Tank-bred and reared specimens are FAR superior to wild-collected. If keeping two individuals, start them small and keep your eyes open for too-severe territoriality over time. You and they don't need, or likely want an anemone. Other writers endorse the use of other tank bred species in small volumes (e.g. Clark's, Tomatos); but I have found these rarely work out in time.

Amphiprion ocellaris Cuvier 1830, the "False" Percula or Clown Anemonefish, or Ocellaris Clown. Indo-West Pacific; eastern Indian Ocean to Australia, to Philippines, to southern Japan. To a little over four inches maximum length. Orange overall (except for melanistic forms), with three broad continuous body bars with narrow black margins (vs. thick ones in A. percula).


Amphiprion percula (Lacepede 1802), the "True" Percula or Orange Clownfish. Western Pacific; New Guinea, GBR, Solomon Islands, Melanesia. To about four inches in length. Mutualistic with Stoichactis, Macrodactyla and Radianthus anemones.ã''



Do take heed of the species and genera identified above as appropriate and avoid others of the family. Other Damsel genera get too big, are too pugnacious, or just can't adapt to small volumes for whatever reason/s. Other Clownfish species are inappropriate for "Nanos" even if bred/reared in captivity, grow too large and mean for use in small systems.

In terms of picking out individual specimens, look for smallish, outgoing ones in good shape. In particular, select against broken fins, missing scales or otherwise blemished specimens. Don't buy just arrived fishes, instead choosing amongst ones that have been on hand for at least a few days.

For smaller systems'¦ twenty or so gallons, one specimen, solo is recommended'¦ for larger 30-40 gallon ones, with considerable décor/visual cover, two specimens may learn to get along.

Similar appearing fishes are often harassed, to the point of death at times. Many small bottom dwellers such as Blennioids and Gobioids are left alone; are not evidently perceived as competitors for space and food. As the Pomacentrid/s is likely to be the more/most aggressive species in your system, you should plan on adding it/them last.


Surface area is far more important to these fishes than open/top swimming space. Though there are some other species of Pomacentrids that spend a good deal of their time out and off the bottom, the ones that are suitable for small systems live the majority of their time, in and amongst hard structure (rock, corals'¦) scattered about the bottom. Best for you to arrange decorative elements spaced accordingly so your Damsel/s or Clown/s can dart in and out amongst such structure.


As previously stated, these fishes are notably not particular re what sorts of foods they consume. You will notice that they spend a good deal of the daylight period looking about and picking at algae et al. Better that their systems are not kept scrupulously clean of growing foods, and that some small amount of food be added at least twice a day in addition.


Most all Damsels are wild-collected and do occasionally "come in" with the usual reef fish diseases (Cryptocaryon, Amyloodinium)'¦ Additionally, other external and internal parasites are encountered at times. Wild-collected Clownfishes are notorious for such dire problems, many succumbing to Brooklynellosis'¦ hence the strong suggestion to buy captive-produced specimens.

One can preventatively treat these fishes'¦ with Quinine Compounds for external Protozoan parasites, Anthelminthics for internal and external worms of all sorts, and anti-protozoal added to foods to discount gut parasites. Generally these regimens are of more harm than good, and considering the low stocking levels of small marine systems, I am more inclined to simply select apparently healthy individuals, and isolate/quarantine them a few weeks ahead of permanent placement.


The majority of Damselfish (including Clownfish) species in the world are unsuitable for small aquarium use; for reasons of temperament, size, and/or psychology. However, there are a select number that live in small "patch" areas in the wild, and do just fine in small systems. The requisite considerations for success with these include selecting the right species, good specimens, and late placement in suitably (densely) decorated settings.

Albeit feisty, Pomacentrids are mostly hardy, interesting and forgiving marine aquarium species.


Bibliography/Further Reading:

Allen, Gerald R. 1975. Damselfishes of the South Seas. TFH Publications, Neptune City, N.J.

Allen, Gerald R. 1979. The Anemonefishes of the World: Species, Care & Breeding; Handbook for Aquarists, Divers and Scientists. Aquarium Systems, Mentor Ohio.

Allen, Gerald R. 1991. Damselfishes of the World. Aquarium Systems, Mentor, Ohio.

Axelrod, H.R. & Warren E. Burgess. 1981. Damselfishes and Anemonefishes. TFH 9/81.

Baensch, Hans & Helmut Debelius. 1994. Marine Atlas, v.1. MERGUS, Germany. 1215pp.

Emmens, C.W. 1984. Damselfishes. TFH 9/84.

Fenner, Bob. 1989. Successfully selling the popular marines. Pets Supplies Marketing 1/89.

Fenner, Bob & Cindi Camp, 1991. Damselfishes, saltwater bread and butter. FAMA 10/91.

Fenner, Robert. 1998. The Conscientious Marine Aquarist. Microcosm, VT. 432pp.

Fenner, Robert. 1999. The indomitable damsels- Family Pomacentridae. TFH 1/99.

Flood, A. Colin. 1992. Those darling damsels. TFH 8/92.

Wilkerson, Joyce D. 1997 Clownfish; a guide to their captive care, breeding & natural history. Microcosm, VT. 216 pp.

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

A peaceful damsel for a nano.../Damsel Compatibility 12/4/11
<Hi Allie>
I have a 25g nano tank currently with two fish: a yellowhead Jawfish and an ORA Spotted Mandarin (I feed often).  I do have very aggressive filtration (a sump, Chaeto, a protein skimmer, 2 water changes per week).  I was hoping to get one last fish - I know that's a pretty big bioload though - that would preferably be an open water swimmer.  I am not finding a whole lot of options.  I was thinking of some kind of damselfish - I have always found them endearing - however, everything I have read says that all of
them are aggressive.  After reading through the info on your site about them, it sounds like some are less so, such as yellowtail damselfish. 
Seeing as this is a nano, however, I understand that there isn't a whole lot of territory so I am thinking my situation is different.  Out of all the damsels, which, in your opinion, would fit best in my small tank, be least aggressive, and do fine alone?
 If there aren't really any damsels, could you suggest an open water swimmer?  I have high flow so I don't know how well a Firefish or a Cardinalfish would do.
<Since you presently have no damsels, I believe one Yellow Tail Damsel (Chrysiptera parasema) or  Starki Damsel (Chrysiptera starcki) would be a good choice for your system.  Since one or the other will be the new kid on the block, there should be little to no aggression toward other tankmates provided ample hiding places are available.>
<You're welcome.  James (Salty Dog)>

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