Page 51 - Fish and Amphibians (Britannica Illustrated Science Library)

46 DIVERSITY

Time to Eat

ost fish feed within their aquatic environment. Some species,
Its prey includes
however, seek their food outside the water. The best-known spiders as well
M example is the archerfish, which shoots streams of water from as flies and
other insects.
its mouth to knock spiders and flies off nearby plants and into the water.
The African butterfly fish eats flying insects, which it traps after a brief
flight. The river hatchetfish has a similar strategy: its long pectoral In a vertical
fins and flattened body enable it to make great leaps. position, it
sees the prey
well enough Leap
to attack it.
Not only can archerfish shoot
their prey, but they can also leap
out of the water and make the
prey fall in order to eat it.
Archerfish Technique Angle of vision 5 feet
The tongue presses upward against Archerfish have large
Seven species of archerfish live in the a groove in the roof of the mouth, eyes and excellent vision (1.5 m) African Butterfly Fish
tropical waters of India and southeast Asia. forming a tube for emitting the for hunting. At an angle close to Range of the 12 inches
They hunt using an unusual technique of stream of water. 90° to the surface water stream for It inhabits pools and slow rivers in Africa, from
spitting streams of water. of the water, it an adult fish (30 cm) The jaws of the archerfish play Nigeria to the Republic of the Congo. The butterfly
Groove in roof Movement 90º focuses on the prey. a vital role in the hunt. fish hunts in small groups near the shore, hiding
of mouth of tongue HEIGHT IT CAN among roots and floating plants. It uses its pectoral
REACH IN ONE
JUMP Warm fins to “fly” out of the water to capture food or to
escape from predators. It eats flying insects, which it
EXACT ANGLE OF 4 inches
3.1 VISION (10 cm) Temperature of traps on its short flights, and small fish.
inches the waters the
(8 Range of the archerfish inhabits
cm) water stream for
The tongue acts a young fish 6.6 feet (2 m)
as a valve to
keep the water
9.4 inches (24 cm) The pectoral fins power its leap. MAXIMUM LENGTH OF A LEAP
under pressure.
In the water
the tail powers
its ascent to
the surface.
Strategy
The carnivorous archerfish has developed a
special strategy for hunting live insects, which is
highly effective for hunting prey outside the It looks at The pectoral fins
water at distances of up to 5 feet (1.5 m). the prey and serve as wings.
shoots a
stream of
water.
Archerfish African butterfly fish
Toxotes jaculatrix Pantodon buchholzi
When the
insect falls Found in southeast Asia,
into the water, India, and northern Large, well-focused eyes
for effective hunting
the fish Australia, it lives in brackish
devours it. waters with temperatures of
77-86° F (25-30° C).

Hatchetfish
This carnivorous, freshwater fish comes
A SEARCH B SHOT C AIM from South and Central America. It
The archerfish When it finds its prey, If the first 2.75 inches swims in schools and can reach lengths of
looks upward in the archerfish positions stream misses, up to 2.75 inches (7 cm). It always swims
search of its prey. its body upright and the fish tries (7 cm) very close to the surface. Its long
shoots a stream of again and again.
pectoral fins and flattened body enable it
water at the target.
LENGTH OF THE HATCHETFISH to leap high out of the water.
Hatchetfish
Gasteropelecus sternicla