Holochilus chacarius
The dorsal pelage is pale reddish-brown, with long black guard hairs, the flanks are buff or ochre, the throat and chest are white and the rest of the underparts are buff or grey, the hairs having white bases.It is a semi-aquatic species and is found in swamps and other areas of wetland,[1] flooded pasture and cultivated fields, but seldom in forested habitats.In Paraguay it inhabits ground well covered in leaf litter and herbaceous plants.[3] The Chaco marsh rat can swim and dive, and can also climb well; it is a herbivore, feeding on a range of plant materials including sugarcane, rice, banana and other crops.The overall population is thought to be declining, but the rat has a wide range and is present in a number of protected areas, so the International Union for Conservation of Nature has assessed its conservation status as being of "least concern".