News for Brazilian Land Snails
by Jose Coltro
During the last eighty or ninety
years, Brazilian land shells have been almost forgotten by most
biologists and collectors. Abbott listed most of them as "extinct"
in his Compendium of Landshells. Since the 1910 papers by von
Ihering, or even before, with Pilsbry's work, the studies on
many species were done through an occasional expedition to the
Atlantic Rain Forest - probably the richest forest in the world.
When the Portuguese arrived in
Brazil, in 1500, almost all the Brazilian coast from Rio Grande
do Norte to Rio Grande do Sul were densely covered by an incredible
forest. There they found a tree that they called "pau-brasil"
(pau=wood, brasil=fire) and they used this name for the new
land. The trees were perfect for boats and to produce a kind
of pigment. Immediately the Portuguese and others (especially
French pirates) started to export large quantities of this "pau-brasil,"
plus mahogany, jacaranda, and others. It was the beginning of
the destruction of the Atlantic Forest. In the 1500's the Portuguese
colonization brought thousands of people for agriculture. They
planted sugar cane widely all along the coast and took down
more of the forest. In the next centuries others crop -- coffee
or corn, even wood exportation -- destroyed more than 2 million
square kilometers of this rich forest.
Today less than half million
square kilometers resist man's destruction. Most of this forest
was preserved in state parks in Sao Paulo State and in large
cacao farms in Bahia State.
Bahia is the most important landshell
province in all Brasil, and one of the richest in the world.
There are a large number of species, most of them in plentiful
in terms of specimens. But since the beginning of this century,
species like Neobeliscus calcarius (Born, 1778) and Polygyratia
polygyrata (Born, 1778) have not been found. In 1990 we decided
to try to explore some cacao farms and we found a live specimen
of the "extinct" Obeliscus obeliscus (Moricand, 1833).
On the following year we sent an expedition to this area; our
people were able to find a large quantity of the "extinct"
species after decades of their being unobtainable to collectors
worldwide. We sent specimens also to two of the best Brazilian
Malacological Museums - our National Museum, in Rio de Janeiro,
and the Zoological Museum of the University of Sao Paulo. Finally
the anatomy of most of these species was studied. We felt they
were securely protected because most of these species live in
forest that protects the cacao farms. The cacao tree needs a
lot of shade to produce the fruits, so farmers try to protect
the natural forest to provide this shade.
But since last year a plague
has been attacking the cacao tree - the local farmers call it
"vassoura de bruxa" ("witch broom"), a fungus
that destroys the tree; there are no easy treatments for it,
except to cut the tree! Large number of farms are losing the
cacao trees and farmers have begun exchanging cacao culture
for that of bananas or sugar cane. The original forest that
protects the cacao, and the flora and fauna besides, is being
cut down every day.
Some of our people are not finding
many of the good spots for collecting now - where they found
a wonderful forest two years ago, now they encounter only sugar
cane or bananas. Even worse, the area has been treated by agricultural
poisons to protect the new crops and thousands of dead shells
were found, no live ones!
The Brazilian government is setting
scientists to the task of eliminating this plague, so that the
cacao culture can maintain this part of Brasil as a nice link
between man and nature. If the cacao trees disappear, the interdependence
of the forest and the cacao crop will vanish too, new crops
will continue to be planted and the forest will no longer be
needed. About 5 million people live in this area -- most of
them owe their survival to this cacao crop. To solve their social
problem the farmers will have to choose between a new crop or
the forest. The government knows that it is very important to
keep the forest, but they also know that they have to help the
people who live in this area. If in these next few years a solution
does not appear, the forest will disappear and Abbott will be
right to use "extinct" for these species.