The invasive status of Macrobrachium rosenbergii (De Man, 1879) in Northern Brazil, with an estimation of areas at risk globally

Introduction of Macrobrachium rosenbergii to Brazil for prawn farming has resulted in escapes to the local natural environment. In some areas risk of feral populations establishing in local environments is considered low due to a lack of suitable habitat for completing the life cycle. In contrast, introduction of this species along the mangrove coasts of northern Brazil can result in escape to highly suitable habitat for reproduction. We confirm colonization of these habitats by M. rosenbergii and define this species as a casual exotic in Brazil. We highlight that natural reproduction is now occurring, meaning that feral populations may soon become self-sustaining. Ecological niche models using the Maxent software were developed to assess potential areas at risk of invasion in Brazil and more widely across the world. These models indicate that there are large areas of suitable habitat available in northern Brazil where introduced populations of M. rosenbergii could expand. The effect of such introductions could extend to a very large area, from Maranhao in Brazil to the Orinoco delta in Venezuela.