Hydrops triangularis (Wagler, 1824) “Cobra-d’água”

(Figs. 15.8 and 28.2)

First record in the Caatinga. It was recorded only from the state of Maranhão, municipality of Timon in the northwesterns borders of the Caatinga and contact with Cerrado and Amazonia. It is also distributed in the Amazon Forest and Cerrado regions (Cunha & Nascimento 1978; Martins & Oliveira 1998; Nogueira et al. 2010, 2011). We believe this species can be found in other areas of the Caatinga next to its contact with Cerrado. It is an aquatic snake that inhabits water bodies (Scartozzoni 2009). It is diurnal and nocturnal, and feeds on fishes (Scartozzoni 2009).