with a healthy algae crop can help meet a boxfish’s nu-
tritional needs as well (obviously, this is a bane to reef
aquarists, but good for a boxfish). I recommend feeding
boxfishes two or three times a day.
If you feed flake food, or any other food that floats,
be sure to saturate it with seawater before adding it to the
tank so it sinks immediately. It is possible that a boxfish
will ingest air when feeding at the surface and may have
difficulty expelling it. This can cause buoyancy prob-
lems—the fish may be unable to maintain its position
in the water column. Often an affected fish swims with
its tail well above its head and may end up wedging itself
between rocks or under a piece of coral. If this occurs,
you can only pray that the fish expels the air through its
mouth or anus.
Unfortunately, boxfishes are parasite-prone. It is not
rare for them contract marine ich or white spot disease
(Cryptocaryon irritans), but they usually respond well
to the common antiparasite treatments (e.g., formalin
or copper-based medications). Lymphocystis, a viral in-
fection that usually shows up as white, cauliflower-like
growths on the fins, also commonly afflicts boxfishes.
BOXFISH COMPATIBILITY
When it comes to their disposition, the boxfishes are rare-
ly aggressive toward non-related species. Therefore, they
do best when housed with fish tankmates with passive
dispositions, such as anthias, grammas, chromis, flasher
wrasses, gobies, and firefishes. Very large boxfishes have
been reported to eat smaller fishes in the wild, but these
incidents are, we suspect, rare. (Can you imagine one of
these bulky ostraciids chasing down a small fish meal?)
If you want to house more than one boxfish in the same
tank, keep a male and a female. It is also possible to suc-
cessfully house two females together in a large aquarium,
but there is an inherent risk in keeping two males in the
same tank, as they are likely to quarrel. Fortunately, most
of the Indo-Pacific members of the genus Ostracion are
sexually dimorphic and sexually dichromatic; males at-
tain a larger size and usually display dramatically different
color patterns. For example, Yellow Boxfish (Ostracion cu-
bicus) females are yellow with black-bordered white spots,
while the larger males are purplish brown with faint spots
(males are rarely seen in the aquarium trade). Both male
and female juveniles are yellow with black spots. There
is still debate as to whether boxfishes are gonochoristic
(they do not change sex) or protogynous hermaphrodites
(they change sex from female to male).
Boxfishes are more likely to be the victims of aggres-
sion, although their tankmates often ignore them. As
mentioned previously, cleaner wrasses (Labroides spp.)
have been known to harass them incessantly, directing
their cleaning activities at pigment spots on the boxfish’s
body. Because they are not very fast, boxfishes have a
hard time getting away from a persistent cleaner wrasse.
However, boxfishes often seek out cleaner shrimp spe-
cies, apparently enjoying the massage that these crus-
taceans deliver. Be aware that some large crabs and
more potent sea anemones (especially carpet anemones,
Stichodactyla) can kill these fishes.
Thus ends our overview of these fascinating fishes.
While they are not for the faint of heart because of
their potential to “nuke” an aquarium, they can make
wonderful pets if extra care is taken in handling and
tankmate selection.REFERENCES
Beebe, W. and J. Tee-Van. 1928. The Fishes of Port-au-Prince Bay,
Haiti: With a Summary of the Known Species of Marine Fish of the
Island of Haiti and Santo Domingo. New York Zoological Society,
New York.
Kalmanzon, E., et al. 2003. Receptor-mediated toxicity of
pahutoxin, a marine trunkfish surfactant. Toxicon 42 (1): 63–71.
Raveendran, T.V. and E. Harada. 2001. Impact of predation
by Ostracion immaculatus (Pisces: Ostraciidae) on the
macrofouling community structure in Kanayama Bay, Kii
Peninsula (Japan). Pub Seto Mar Biol Lab 39 (2–3): 79–87.
Thomson, D.A. 1964. Ostracitoxin: An ichthyotoxic stress
secretion of the boxfish, Ostracion lentiginosus. Science 146
(3641): 244–45.
Williams, D.E. and A.J. Bright. 2013. White rings on the
threatened coral, Acropora palmata, associated with foraging
activity of the honeycomb cowfish, Acanthostracion polygonius
(Ostraciidae). Coral Reefs 32 (3): 651.Juvenile Thornback Cowfish (Lactoria fornasini)
Small juvenile Yellow or Cube Boxfish (Ostracion cubicus)