Nectomys rattus (Pelzeln, 1883)

Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Cricetidae, Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona: Lynx Edicions, pp. 204-535 : 449

485.

South American Water Rat

Nectomys rattus

French: Nectomys dAmazonie / German: Stidamerika-\ Wasserratte / Spanish: Rata de agua suramericana

Other common names: Amazonian Nectomys, Common Water Rat

Taxonomy. Hesperomys rattus Pelzeln, 1833 , “Marabitanas,” right bank of the upper Rio Negro, Amazonas, Brazil.

This species is monotypic.

Distribution. E Colombia, Venezuela at Orinoco Basin, Peru at Ucayali Basin, Guyana, French Guiana, Paraguay, and Brazil, from right bank of Rio Parana and left bank of Rio Sao Francisco toward NW.

Descriptive notes. Head-body 127-290 mm, tail 120-255 mm, ear 15-30 mm, hindfoot 38-60 mm; weight 102-430 g. See general characters of the genus under the Trinidad Water Rat (N. palmipes ) account. Dorsum of the South American Water Rat is grayish brown; underparts are pale gray, slightly orangish; and hypothenar pad is absent. Lacrimals contact mainly maxillary bone, and interparietal tends to be sharpened. Chromosomal complement varies according to presence of B chromosomes at 2n = 52-53 and 54, FN = 50, 52, B4, and 56.

Habitat. Different vegetation types near watercourses, such as grasslands, gallery forest, dry forest, moist forest, and “buritizal” (open humid grasslands, with large buriti palms, Maunritia flexuosa) formation and in outskirts of towns.

Food and Feeding. No information.

Breeding. No information.

Activity patterns. The South American Water Rat is nocturnal.

Movements, Home range and Social organization. Home range of the South American Water Rat averages ¢.2200 m?; densities are 2-6 ind/ha.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The South American Water Rat has a wide distribution and presumably large overall population and is tolerant of some habitat disturbance. It is associated with transmission of schistosomose and leishmaniose.

Bibliography. Bonvicino & Weksler (2015), Catzeflis et al. (2016), Chiquito (2015), Hannibal & Caceres (2010), Lainson & Shaw (1969), Mares & Ernest (1995), Musser & Carleton (2005), Ribeiro et al. (1998), Voss et al. (2001).

Figures

458. Forest Small Rice Rat (Macroryzomys minutus), 459. Highland Small Rice Rat (Microryzomys altissimus), 460. Peruvian Rice Rat (Oreoryzomys balneator), 461. White-throated Montane Forest Rat (Drymoreomys albimaculatus), 462. Gray Rice Rat (Eremoryzomys polius), 463. Medium-tailed Rice Rat (Eremoryzomys mesocaudis), 464. Lund’s Water Rat (Lundomys molitor), 465. Paraguayan Rice Rat (Sooretamys angowya), 466. Brazilian False Rice Rat (Pseudoryzomys simplex), 467. Venezuelan Marsh Rat (Holochilus venexuelae), 468. Amazonian Marsh Rat (Holochilus sciureus), 469. Chacoan Marsh Rat (Holochilus chacarius), 470. Brazilian Marsh Rat (Holochilus brasiliensis), 471. Crafty Marsh Rat (Holochilus vulpinus), 472. Lagiglia’s Marsh Rat (Holochilus lagigliai), 473. Langguth’s Rice Rat (Cerradomys langguthi), 474. Vivo’s Rice Rat (Cerradomys vivoi), 475. Maracaju Rice Rat (Cerradomys maracajuensis), 476. Lindbergh's Rice Rat (Cerradomys scotti), 477. Akroa Rice Rat (Cerradomys akroai), 478. Marinho’s Rice Rat (Cerradomys marinhus), 479. Terraced Rice Rat (Cerradomys subflavus), 480. Goytaca Rice Rat (Cerradomys goytaca), 481. Ucayali Water Rat (Amphinectomys savamis), 482. Trinidad Water Rat (Nectomys palmipes), 483. Magdalena Water Rat (Nectomys magdalenae), 484. Western Amazonian Water Rat (Nectomys apicalis), 485. South American Water Rat (Nectomys rattus), 486. Atlantic Water Rat (Nectomys squamipes)

Distribution. E Colombia, Venezuela at Orinoco Basin, Peru at Ucayali Basin, Guyana, French Guiana, Paraguay, and Brazil, from right bank of Rio Parana and left bank of Rio Sao Francisco toward NW.