Vipers in the state of Acre, western Brazilian Amazon: a review

Snakes of the family Viperidae are distributed in many different ecosystems, generally being the most abundant species in snake surveys and studies on snake assemblages in Brazil. These species are medically important as they can cause snakebites and are responsible for approximately 99% of envenomings in humans in Brazil. Considering the ecological importance of snakes in terrestrial ecosystems, mainly as important predators in food webs, and in public health due to the risks of snakebites, here we review the information available in the literature about vipers in the state of Acre, western Brazilian Amazon. Six species of vipers were already recorded for Acre, with Bothrops atrox being the most abundant, present in various types of habitats and being the main species involved in snakebites. Bothrops bilineatus is the most common snake found in a floodplain forest in the protected area Japiim Pentecoste, a factor probably associated with prey availability. The other four species of vipers (Bothrocophias hyoprora, Bothrops brazili, B. taeniatus and Lachesis muta) are less frequent and associated with unflooded forests. Although we found in the literature several studies involving vipers in Acre, there is a need for more studies on these snakes in the region, addressing their ecology, ethno-herpetological questions and snakebites, including research on their ecology and behavior in the field, genetic variation and differentiation among populations and species, and biochemical composition of venoms.