Occasional release of guppy, Poecilia reticulata (Cyprinodontiformes, Poeciliidae) in Upper Paraguay River Basin, Mato Grosso State: a new threat to rivers forming the Brazilian Pantanal?

摘要

The guppy, Poecilia reticulata Peters, 1859 is an ovoviviparous freshwater fish of low waters native to the Caribbean Islands, Venezuela, Guyana, and northern Brazil (Amapá and Pará States) (Reis et al., 2013). Guppies are among the most popular fishes in the aquarium trade (Magalh?es and Jacobi, 2013), and they are introduced into water bodies in many parts of Brazil through the aquarium dumping (Oliveira et al., 2014). This paper reports the first record of non-native P. reticulata in water bodies at midwest Brazil. Poecilia reticulata (Figures 1-4) was collected in nascent of stream Figueira (14o38'98" S and 57o29'54" W) located to eastern of Tangará da Serra, southwest region of Mato Grosso State. Samples were made at November 2015 using trawl (0.1 mm mesh) and sieve (2.0 mm mesh) in shallow waters during the day (two persons during 5 minutes), catching 350 specimens of guppy (148 females, 129 males and 73 juveniles). Fishes were euthanized (Borski and Hodson, 2003), fixed in 10% formalin and later stored in 70% ethanol. Voucher material is deposited in the fish collection of the ‘Museu de História Natural Cap?o da Imbuia', Curitiba, State of Paraná, Brazil (MHNCI)