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Pirarucu - Arapaima gigas
Why Breathe Air?
Amazon aquatic environments are influenced dramatically by
the region's unusual characteristics. Seasonal rains can raise and
lower water levels by as much as 40 feet. Daily variations in temperature
and photosynthesis (plant respiration) can cause wildly varying levels
of dissolved oxygen in Amazon waters. As a result, many Amazon fishes
are routinely subjected to periods when their waters contain extremely
low levels of oxygen (hypoxia or anoxia).
In order to survive these deadly
conditions, many species have evolved unique respiratory strategies.
Some absorb oxygen through their skin, others take advantage of multiple
versions of oxygen carrying hemoglobin in their bloodstream.
Many species simply migrate to avoid the difficult times. The arapaima,
however, has literally risen above it all.
These lumbering Amazon giants
have evolved the ability to simply rise to the surface and gulp air.
Their modified swim bladders act as lungs, dispersing oxygen into the bloodstream.
Their gills return the waste CO2 gases to the water. It's a
neat system that allows arapaima to swim blithely along in conditions that
would rapidly suffocate other fishes. Millions of years of evolutionary
adaptation enabled them to prosper and proliferate throughout the Amazon.
Nature's work however, is often quickly undone by man.
This once plentiful species suffers the misfortune
of beimg particularly tasty to humans. The same air-breathing mechanism
that allows them to survive the worst possible natural conditions proves
to be their undoing when it comes to mankind. They are obligatory
air-breathers -- and they must come to the surface in order to breathe.
They would drown, just like us, if they couldn't periodically gulp
air. This makes them an easy target for patient, harpoon wielding
hunters who bring their flesh to market. Only recently have measures
been taken to protect this magnificent Amazon giant.
Thislarge specimen (about 185 pounds) took
a floating cut bait.
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Osteoglossiformes are an
extremely ancient order of prehistoric freshwater fishes. The arapaima,
paiche or pirarucú, as it is known in Brazil, is the largest, scaled,
wholly freshwater fish in the world. Fish over 3 meters (almost 10
feet) and up to 275 kg (600 lbs) have been recorded. At first glance,
pirarucú look like an Amazon version of a tarpon, with a similar
profile save for their flattened head and strange, club-shaped tail.
The pirarucú's flesh is much sought after throughout the Amazon
and for this reason, large specimens are becoming very rare.
This giant specimen was photgraphed at the Japanese
Natural History Museum in Manaus, Brazil.
Although not usually pursued as a sport fish in
the Amazon basin, pirarucú can be taken on conventional tackle with
a little patience and a lot of persistence. They have been
caught using a variety of large (7-inch or so) jerk baits (14-18 size Rapalas,
big Bombers and Red-fins), although a large live baitfish (on a 14/0 circle
hook) dropped under a big float is probably the best bet in areas where
anglers are common. Arapaima will, on rare occasions take a streamer
fished in the deep lagoons it prefers to haunt. They are normally
a very wary fish and must be approached with extreme caution. However,
when guarding a spawning site, they have the unsettling habit of surfacing
close to your boat like a giant prehistoric submarine, on occasion even
leaping entirely clear of the water. Considering their size, and
their brilliant array of spawning colors, this is an impressive performance.
Pirarucú have both gills, which they use to release C02, and a modified
air bladder structure that acts as a lung, which they use to gulp in air,
supplying oxygen. Stout tackle is a must for these giants -
For the determined fly fisherman, an 11 or 12-weight rod, 400-grain sink-tip
line, heavy leaders and large streamers tied on 7/0 heavy saltwater hooks
are standard equipment.
Though pirarucú are sometimes found in 'fishable'
numbers (mainly in Brazil, Guyana and Peru), it is important to note that
a great deal of time, patience and probably plain luck must be devoted
to the fish if one is to catch one on a fly rod. It is not an everyday
occurence in peacock bass waters
The aruanã (Osteoglossum
bicirrhosum) is a close relative of the pirarucú.
They are a schooling fish that in rare cases can reach a maximum weight
of about 20-pounds. They are generally plentiful in peacock bass
waters and make an interesting accompaniment to a peacock trip. Aruanã
are extremely surface-oriented and can often be sight-fished as they
cruise about just below the surface in search of prey. They take
the same lures used for smaller peacocks (and especially love Heddon Zara
spooks). They are a delight for fly fishermen. A 7-8-weight
fly rod, floating line and a variety of medium-sized poppers and sliders
(2/0) make for some exciting fishing. When hooked, aruanã
repeatedly jump like a baby tarpon. |
Aruanã - Osteoglossum bicirrhosum
The natives call this odd-looking silver creature "macaco
d'agua", "water monkey" bcause of its ability to leap more than six
feet out of the water. In addition to small fish, aruanã eat
insects, small birds, bats and reptiles, which they will often snatch from
overhanging branches.
Their large, light-reflecting, opalescent
scales and their fluid swimming movements make them underwater billboards
for the sight fishing angler. They take a bait by opening their cargo-door
mouth,
inhaling it and then closing the gate. Although
not a particularly powerful fish, they are highly prized as a gamefish
by many Brazilians.
The aruanã is also a very popular
aquarium fish . One of the few remaining examples of fishes surviving
from the Jurassic period, they give observers a peek into an ancient prehistoric
world.
Aruanã take surface lures and flies.
Osteoglossid Reproduction
The arapima fans a large circle free of debris in sandy bottom
areas. Eggs are laid in the 3 to 6 foot diameter nest. Aruanã,
with two odd, fleshy barbels on their lower jaw, are mouth brooders.
Males carry the relatively small number of eggs and young in their mouths,
thus increasing their chances for survival. |
