Common names: Alcatrazes lancehead.

Bothrops alcatraz is a venomous

Venomous snake

"Poisonous snake" redirects here. For true poisonous snakes, see Rhabdophis.Venomous snakes are snakes which have venom glands and specialized teeth for the injection of venom...

 pitviper

Crotalinae

The Crotalinae, commonly known as "pit vipers" or crotaline snakes, are a subfamily of venomous vipers found in Asia and the Americas. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on either side of the head...

 species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 found only on an island off the coast of southeastern Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

. No subspecies are currently recognized.

Description

Grows to a maximum size of 46.2/50.5 cm for males/females. Its small size and relatively large eyes are considered paedomorphic (juvenile) characteristics.

Geographic range

Found only on Ilha Alcatrazes, 35 km off the coast of São Paulo

São Paulo

São Paulo is the largest city in Brazil, the largest city in the southern hemisphere and South America, and the world's seventh largest city by population. The metropolis is anchor to the São Paulo metropolitan area, ranked as the second-most populous metropolitan area in the Americas and among...

, southeastern Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

. This island, which has a total area of only 1.35 km², is one of four islands than make up the Alcatrazes Archipelago. The type locality given is therefore the same: "Alcatrazes Island, (24°06'S, 45°42'W), São Sebastião, São Paulo, Brazil."

Conservation status

This species is classified as critical (CRU) on the IUCN Red List for the following criteria: CR B1ab(iii)+2ab(iii) (v3.1 (2001). This means that the geographic range is estimated to be less than 100 km², that this area is severely fragmented or known to exist at only a single location, and that a continuing decline has been observed, inferred or projected for the area, extent and/or quality of the habitat. Furthermore, the area of occupancy is estimated to be less than 10 km², that this area is severely fragmented or known to exist at only a single location, and that a continuing decline, observed, inferred or projected in the area, extent and/or quality of habitat. Year assessed: 2004.