Spawning occurs at
dusk, when a territory-
holding male moves to
a rendezvous site within
his territory to court and
spawn with females. In at
least some species (e.g.,
the Thornback Cowfish,
Lactoria fornasini), the
males attempt to steal fe-
males from their neigh-
bors. They adopt the color
pattern of the female and
sneak into a neighboring
male’s territory. Upon
encountering an adult fe-
male in his rival’s territo-
ry, the intruding female-
mimic male adopts the
normal male courtship
colors and tries to entice
the female to spawn. In
most cases the females are “true” to the territory-holding
male and resist the temptation to spawn with the “cross-
dressing” interloper.
SPACE AND AQUASCAPING
The size of the boxfish aquarium depends on the spe-
cies you intend to keep. There are medium-sized spe-
cies (most under 7 inches/18 cm in total length), and
then there are large species (regularly over 12 inches/30
cm long). Adult members of the first group should be
housed in a tank holding at least 75 gallons (284 L), but
the beefier members of the family will need a tank hold-
ing 300 to 500 gallons (1,200–1,900 L). (See table on
page 57 listing some representatives from each group.)
While these fishes actively move over the reef seeking
food, they do not swim rapidly and they often hover near
reef crevices, under overhangs, and in caves (e.g., Spot-
ted Boxfish, Ostracion meleagris). Therefore, they need
room to move, but they also need suitable shelter. Some
boxfishes inhabit more “open country,” like sand slopes
and seagrass meadows (e.g., the Longhorn Cowfish, Lac-
toria cornuta). I have seen fishes that are more at home
in this open type of habitat get stuck between a piece
of aquarium décor and the glass wall or between pieces
of live rock. I have also seen them get stranded atop or
behind aquarium equipment, and small specimens are
prone to getting sucked into intake tubes and overflow
boxes. Take these things into consideration when select-
ing and aquascaping the boxfish aquarium.
While water movement is needed to provide ad-
equate oxygenation and circulation, an extremely strong
flow can buffet these cumbersome creatures and cause
them undue stress. If you do have lots of laminar flow in
your aquarium, make sure there are some “quiet” areas
where your boxfish can escape from direct water streams.
Creating such a microhabitat is more difficult in a small
tank, and some aquarists house juvenile boxfishes with
seahorses, as they tend to like a similar rate of flow.
While most boxfishes do best in water temperatures
normally proposed for tropical marine aquariums, a few
members of the family, including Shaw’s Cowfish (Ara-
cana aurita), the Ornate Cowfish (A. ornate), and the
Humpback Boxfish (Anoplocapros lenticularis), hail from
the cooler climes of South and Southwestern Australia.
These fishes are normally found at water temperatures
of less than 70°F (21°C), but it is best to keep them at
around 55 to 65°F (13–18°C ). Some people report suc-
cessfully keeping these species at water temperatures of up
to 72°F (22°C), but if you want to ensure long-term suc-
cess, a cooler water temperature is recommended.BOX ON A REEF
How about a boxfish in a reef tank? The boxfishes have a
dubious reputation when it comes to being good neigh-
bors for invertebrates. As mentioned above, in the wild
they feed mainly on sessile invertebrates, especially tu-
nicates and sponges. However, the larger species are also
known to ingest a range of desirable invertebrates. For
example, the Scrawled Cowfish (Acanthostracion quad-
ricornis), which is a large species regularly collected on
Florida reefs, feeds primarily on sponges and tunicates,
but it will also consume zoanthids, corallimorpharians,
anemones, hermit crabs, blue-green algae, Halimeda
algae, gorgonians, seagrasses, polychaete worms, and
small bivalves (Randall 1961). It has also been reported
to feed on the spines of small club-spined sea urchins.
In the larger species, there is an ontogenetic shift in diet
that is a function of their maturing dental “machinery”Lactoria cornuta, the Longhorn Cowfish, is one
of the most widely kept aquarium species.