What's your favorite Butterflyfish? A "Heni"?, Threadfin, golden, a double saddle-back? At the top of my personal list are the two, yes two raccoon butterflies, Chaetodon lunula ("Key-toe-don lew-new-lah"), and Chaetodon fasciatus ("fah-see-ah-tus").
These B/F's (industry shorthand for Butterflyfishes) are hardy, disease resistant, ready eaters to the point of being porky, and strikingly beautiful. As marines go, they're moderately inexpensive and readily available.
Specimens that have been conscientiously collected, held and transported are long-lived in captivity. Ones that have not... will be easy for you to discern with what's offered here.
Classification: Taxonomy, Relation With Other Groups
The raccoons are just two of 89 species in the giant genus Chaetodon, of the Butterflyfish family Chaetodontidae of ten genera and some 120 nominal species. See Nelson for higher taxonomic affinities.
Chaetodon lunula, "the" raccoon butterfly, is found widely throughout the tropical Indo-Pacific, eastward even to Hawaii (my favorite source), westward to the Indian Ocean but missing in the Red Sea.
Chaetodon fasciatus, the "Red Sea" raccoon butterfly is so-named for its restricted distribution. Happily for the world of marine aquarists, Red Sea livestock is becoming much more available in terms of numbers to be had and lowered cost.
Both species bear black and white crescent bands over the face and eyes raccoon-mask-like imitating their terrestrial namesake. They're similarly colored yellow, black and white on first glance, yet look closer. The Red Sea species lacks the Indo-Pacific's caudal peduncle (the area right before the tail fin) black spot and oblique yellow stripes behind the head. Note also the differences in the Red Sea's white masking (less), it's bolder, more variegated body band markings, and gorgeous red margining on the unpaired fins.
Raccoons can tip the scales at more than nine inches, total length, and grow an inch or better in a half year. Not the biggest B/Fs, but close. They need room to swim and grow.
Selection: General to Specific
The following course of observation and action...
1) Timeliness: How long has the dealer had the fish? I strongly suggest holding off purchasing butterflies for a good week or two after arrival. Shaky individuals will have straightened out by then, or gone the route.
2) Feeding: Any marine fish of considerable cost should have to pass the acid-test of whether it is eating. No feeding, no sale.
3) Appearance: Off color, and any reddening of the mouth or fin bases should disqualify a prospective purchase. Most often due to mis-handling, such specimens refuse food, rarely recuperating.
4) Size: On acquisition is important. Small and large butterflies ship and adapt poorly; avoid ones under 3 inches and over 5 if at all possible. Intermediate size specimens acclimate well to captive conditions.
Collecting Your Own
Can be done if you just happen to be in the area. These and all other Butterflyfishes are captured using a "fence net" arranged as a barrier, and hand nets (and possibly poles) to drive intended specimens against it.
Raccoon B/Fs live in shallow regions of coral reefs; with both ready holes to swim in/out and dive into, and plenty of open space. Note that these species can and do get pretty big (more than hand size), and don't tolerate crowding; a small specimen requires a good fifteen gallons itself, a larger individual a minimum of thirty.
Butterflyfishes as a whole do not appreciate much in the way of nitrite or nitrates. A successful approach to their keeping is to place them in established (six months plus) aquariums that are adequately equipped with filtration geared toward maintaining low organic concentrations (e.g. fractionation, chemical absorbers).
Steady and high specific gravity (1.025 for both species), and pH (ideally 8.3) are requisite. Bottom line; these fishes need consistent high quality water.
A "dream" filter set-up might involve a separate "refugium" aquarium to circulate water to and from your main display system. This other tank would have its own lighting gear and be filled chock-a-block with thriving live rock, a live sand arrangement to eliminate nitrates, heating, protein skimmer... even provide some supplemental live food!
Raccoon butterflies are most often seen singly, periodically in pairs, only occasionally in groups. Unless you purchase or capture them together, they are best kept one to a tank. Likewise, other Butterflyfish family members can butt-heads should they be closely matched size-wise or if the system is crowded. My suggestion is to keep an inch or so difference in your new chaetodonts and introduce the smallest first, with a few weeks span between them.
Following a two week quarantine (or at least a brief freshwater dip), even coming from a reputable dealer, a "mixing" or "dripping" of waters acclimation procedure should be followed, placing the new specimen in its new home under low illumination for a day. Do this when you have time to observe carefully; the first minutes to hour are critical in terms of determining whether or not the raccoon will "take" or be accepted by its tankmates. Watch your livestock.
I've heard of small Chaetodon lunula kept in reef set-ups, but I don't advise it; raccoons will pick at coral and sample other soft-bodied non-vertebrates to pieces.
Raccoons are good community fishes for fish-only types of systems. Other fish species leave them alone, unless they're bite-size, and they are generally "live and let live" in attitude with the possible exception of members of their own kind and similar size and shaped butterflies.
Reproduction, Sexual Differentiation/Growing Your Own:
Butterflyfishes are egg-scatterers, releasing their gametes to the whims of surface currents cued by moon and tides. Larval young develop through a strange armored "tholichthys" stage as pelagic plankton, settling down (hopefully) as miniature adults.
Per most chaetodonts, the raccoon species are indistinguishable sexually. All specimens are wild caught.
Feeding/Foods/Nutrition: Types, Frequency, Amount, Wastes
As mentioned previously both raccoon species are enthusiastic eaters. Once trained on non-live foods you will have to literally "beat them with a stick" to get them to not feed. New arrivals may require live offerings initially; brine shrimp, Tubifex work well, as does an opened fresh clam. In the wild raccoon B/Fs feed primarily at night, so initially offering food toward the evening is worth considering.
I have seen these fishes maintained on little more than dry-prepared foodstuffs, but with consequent loss of color and vitality. Do alternate meaty foods into their diets (shrimp, clam, mussel, frozen insect larvae, etc.) on a regular and frequent basis. B/Fs are browsers that become "bored" and skinny when fed only once a day; feed often, small amounts.
Disease: Infectious, Parasitic, Nutritional, Genetic, Social
Except on being collected or exposed to new livestock that has brought in "bugs" with it, these fishes are historically "clean". If yours look punkish, are refusing food, look first and foremost to diminished water quality, and second to "bullying" by a tankmate...
Be cautious as to unnecessarily "treating" these (and your other marine livestock) with "medications". The dreaded saltwater Ich (Cryptocaryon) may be "cured" via standard copper treatment, but it is best to avoid it entirely through quarantine and/or dipping.
The raccoon Butterflyfishes are two of the best of the family. As omnivorous feeders on sedentary invertebrates and plankton, they easily adapt to aquarium fare. For chaetodonts, they're parasite resistant... What's more, both are beautiful and interesting behaviorally.
If you have an un-crowded, spacious system, that is well-established and filtered, do consider an aquatic raccoon.
Allen, Gerald R. 1979. Butterfly and Angelfishes of the World. Vol. 2. Aquarium Systems, OH. 203 pp.
Burgess, Warren E. 1978. Butterflyfishes of the World; A Monograph of the Family Chaetodontidae. T.F.H. Publications, NJ.832 pp.
Burgess, Warren E. 1979. The raccoon Butterflyfish, Chaetodon lunula. TFH 8/79.
Campbell, Douglas 1980. Marines: Their care and keeping. Butterflyfishes: Part one. FAMA 10/80.
Hoover, John 1995. Hawaii's Butterflyfishes, pt. 1. FAMA 11/95.
Hunziker, Ray 1992. The ten best butterflies. TFH 6/92.
Nelson, Joseph S. 1994. Fishes of the World. Wiley, NY. 600 pp.
Steene, Roger C. 1977. Butterfly and Angelfishes of the World. Vol. 1 Australia. Aquarium Systems, OH. 144 pp.