Amphinectomys savamis Malygin 1994
Creators: name: Don E. Wilson
name: Russell A. Mittermeier
name: Thomas E. Lacher, Jr
Publisher: name: Lynx Edicions
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Cricetidae
Amphinectomys
Amphinectomys savamis

description: 481.
Ucayali Water Rat
Amphinectomys savamis
French: Nectomys de I'Ucayali / German: Ucayali-Wasserratte / Spanish: Rata de agua de Ucayali
Taxonomy. Amphinectomys savamis Malygin, 1994, 7 km east Jenaro Herrera, right bank of Rio Ucayali (04°55 S, 73°45’ W) in the province Requena, Department of Loreto, Peru (as translated from original in Russian).
Amphinectomys savamis is the type species of the genus. Monotypic.
Distribution. SE Ecuador and NE Peru, known from five localities associated with N & S bank tributaries of Rio Maranon.
Descriptive notes. Head-body 187-190 mm, tail 173-206 mm, ear 21-24 mm, hindfoot 53-54 mm; weight 214-225 g. The Ucayali Water Rat is large, similar to species of Nectomys, with tail longer than head-body length, long and robust hindfeet, and moderately short ears. Pelage is soft, shiny, and glossy, with long dorsal hair (length 22 mm) and dense underfur. Dorsum is dark brown to fulvous brown, sides are more ocherous, and venter is grayish white, with conspicuous countershading. Mystacial vibrissae are dense and very long, extending beyond pinnae when laid back. Pinnae are only slightly hairy and dark brown. Manus and pes are covered dorsally with short, pale hair. Second,third, and fourth digits on hindfeet are much longer than first and fifth digits. Large webs of skin are present on manus and pes between second, third, and fourth digits, extending to bases of claws. Pes has conspicuous white tufts of ungual hair at bases of claws on all digits; plantar surfaces are covered with squamae. Natatory fringes are present along medial plantar margins of metatarsus and first and second digits, and along lateral plantar margins of fourth and fifth digits. Tail is distinctly bicolored (dark above, pale below); tail scales are large; tail has conspicuous keel of hair on ventral surface; and apical tuft is present but inconspicuous. There are four pairs of mammae. Chromosomal complementis 2n = 50, FN = 66.
Habitat. Moist forests. Peruvian Ucayali Water Rats are from Southwest Amazon moist forests, while the Ecuadorean record was from ecotonal region between Napo moist forest and Eastern Cordillera real montane forest. The Ucayali Water Rat has been trapped close to a small creek (0-5-1 m across, 0-5 m deep) in primary forest.
Food and Feeding. No information.
Breeding. No information.
Activity patterns. Morphological adaptations of the Ucayali Water Rat suggests a highly specialized aquatic life. The original type was found in the forest at the edge ofa stream.
Movements, Home range and Social organization. No information.
Status and Conservation. Classified as Data Deficient on The IUCN Red List.
Bibliography. Chiquito & Percequillo (2017), Malygin et al. (1994), Medina et al. (2015), Pacheco, Zeballos & Vivar (2008), Valqui (2001), Weksler & Valqui (2015).
-Peters,1861
description: Published as part of Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Cricetidae, pp. 204-535 in Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona :Lynx Edicions on page 448, DOI: 10.5281/zenodo.6707142