Biology Reference
In-Depth Information
happened to stick to the wall of the tank just above the waterline they
would shoot at it, knock it down, and eat it. I wondered if they could
be “trained” to shoot at something out of the water. Naturally, I set
about to find out.
I took a piece of vinyl plastic and hung it just above the water sur-
face. At feeding time I tossed the food into the water directly in front
of the plastic. The next step was to have some food stick to the plas-
tic, so the archerfish would have to shoot it down. Selecting moist pieces
of ground meat, I lobbed small morsels toward the vinyl sheet. Some
stuck, and sure enough, the archers leapt out of the water to grab the
food or, if they were out of easy leaping range, shot it down. Raising
the piece of plastic higher solved the jumping problem, and they were
forced to use their liquid bullets to get the food. It took only a few days
for the archers to figure out the new feeding scheme; in no time they
were consistently shooting at any food that stuck to the plastic.
Next I stuck a few pieces of food to the plastic sheet prior to feed-
ing time and suspended the sheet above the water. No problem: they
figured that out right away. I then a‹xed a bull's-eye to a piece of plas-
tic, like an archery target—to give the visitors, not the fish, a clue of
what the fish were supposed to shoot at. I now had the makings of a
regular demonstration of archerfish shooting. It was put on two times
a day, and the archers performed well every time.
An interesting example of their learning ability—and perhaps also
of their laziness— occurred when two or three fish gave up shooting
at the food altogether and instead waited in the back until another fish
shot the food o¤ the target. They would then rush in and grab it be-
fore the actual shooter could turn around. Seems like there's always
a cheater in the crowd. The fish world really isn't so di¤erent from
our own.
Having evolved as insect-eating specialists, archerfish are attracted
to the slightest movement above the water. One time, aquarist Al Cas-
tro leaned over the tank four feet above the water, and an archerfish
shot him in the eye with such accuracy and power that his contact lens
popped clean out. Archerfish are attuned to the tiny motions made by
their insect prey, and we figured that when Al blinked, the archer in-
stinctively shot at the movement. They truly are remarkable animals.
Search WWH ::
Custom Search