Arboreal tarantulas -- known from a few tropical places in Asia, Africa, South and Central America, and the Caribbean -- generally have a lighter build, thinner bodies and longer legs than their ground-living cousins, which better suits them for their forest tree habitats, they said.
The new species have been reported in the journal Zookeys by Rogerio Bertani, a tarantula specialist in Sao Paulo.
"Instead of the seven species formerly known in the region, we now have 16," Bertani said.
These species are in highly concentrated habitats in regions where they are suffering high pressure from human activities, researchers said.
In addition all the new species are colorful, the researchers said, which could constitute another threat because it might make them attractive for the pet trade.