The Arrau River Turtle, also known as the Giant South
American River Turtle, Amazon River Turtle, South American
River Turtle; in Spanish as Arrau, Charapa, Gurruņa, and La
Tortuga; and scientifically as Podocnemis expansa, comes
from the rivers and lakes in the Amazon River Drainage
thorough Venezuela, Guyana, Peru, Brazil, Columbia, and
Bolivia, as well as on the islands of Tobago and Trinidad.
This turtle's family of twenty-six species is the same as
that of the largest fossil turtle ever found, which measured
over seven and one half feet long!
The Giant South American River Turtle is, as you might
expect, a very large turtle, as large as some sea turtles,
and is the largest river turtle in South America. It has
been known to grow to weigh over one hundred pounds and
extend to over three feet in length for some females, the
males being somewhat smaller. It has several other
interesting characteristics besides its huge size, as you
will learn below.
Its smooth-rimmed, slightly domed and slightly egg-shaped
carapace is a mottled olive, grey or brown, and seldom has a
keel once the turtle is adult. The plastron has yellowish
tan, red or orange markings, and the neck is usually grey on
top and yellowish tan underneath.
The head of the adult turtle is grey or brown with yellowish
tan markings, the beak is tan, and there are two barbles on
the chin. The legs and tail are grey, with five claws per
front leg and four claws per back leg. This turtle species
belongs to the side-necked family, and draws its neck back
into the shell horizontally. Hatchlings have grey heads with
large bright yellow spots, and yellow spots ringed in black
on their backs.
The Arrau River Turtle is mainly herbivorous and travels
hundreds of miles up and down the Amazon River and its
tributaries every year, feasting on fruits and flowers from
riverside trees and aquatic vegetation in the flooded
forests during the wet season, and eating very little in the
In the dry season the males get much more color on their
heads and legs, and the females congregate together, basking
six or more hours per day on the river bars. Two or three
weeks later, they nest in groups of hundreds, digging yard-
wide and two feet deep holes for each nest, and burying
their eggs in the clear, white river bar sand. As she digs,
the female keeps the sand wet with her urine so it will hold
its shape and allow her to dig another one foot deep nursery
hole at the bottom of the nesting hole. She then lays from
sixty to over one hundred and fifty round eggs, and buries
them. Females also often lay more than one clutch per year.
The brown, two inch long hatchlings emerge, usually at
night, about forty-five days from the egg laying, and head
straight into the water. The young are omnivorous, as are
most turtle hatchlings. Adults eat mostly vegetation, but in
captivity they have been known to eat meat as well.
In captivity these turtles must have experienced and
specialized care. They should also be kept in groups, as
they are much more social that other river turtles, basking
together, cleaning algae from each other's shells, etc.
Breeding maturity is determined by size, females must be over
eight inches and the males over two feet before they are
ready to breed. Another interesting note is that clutches
produces many more female than male hatchlings, at a ratio
of about thirty to one.
This Amazon River Turtle is still sometimes hunted for meat
or eggs, but it is under protected status in Brazil, which
encourages both turtle farming and the efforts which are
underway to increase its numbers in the wild, with eggs
being collected, incubated, and the hatchlings release back
to the habitat when they are large enough to have a better
chance of survival. We hope this very interesting turtle
will be around in the wild for many more generations to come.