Ichthyomys hydrobates (Winge, 1891)

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 : 407

346.

Common Crab-eating Rat

Ichthyomys hydrobates

French: Ichthyomys de Winge / German: Gemeine Krabbenratte / Spanish: Rata cangrejera comun

Other common names: Crab-eating Rat, Silverbellied Ichthyomyine

Taxonomy. Habrothrix hydrobates Winge, 1891 , Sierra de Mérida, Mérida, Venezuela.

As currently recognized, I. hydrobates is widely distributed across dissected mountainous terrain and includes at least three diagnosable different populations usually treated as subspecies.

Subspecies and Distribution.

I.h.hydrobatesWinge,1891—WVenezuela.

I.h.niceforiThomas,1924—WColombia.

I. h. soederstroemi de Winton, 1896 — NC Ecuador.

Descriptive notes. Head-body 134-182 mm,tail 125-150 mm, ear 8-10 mm, hindfoot 30-36 mm. No specific data are available for body weight. Dorsum of the Common Crabeating Rat is bright brown gray, sometimes with hairs of lighter ends intermingled, giving mottled appearance. Venter is pure white to silver gray, with dark gray hairs at bases. Tail is uniformly dark. Outer edges of feet and fingers have fringes of rigid silver-to-white hair.

Habitat. Andean tall rainforest, cloud forest, or secondary forest at elevations of c.1000-2800 m. The Common Crab-eating Rat is currently found along banks of forest streams or irrigation canals in agricultural areas.

Food and Feeding. Diet consists of crabs and other aquatic invertebrates.

Breeding. No information.

Activity patterns. The Common Crab-eating Rat is diurnal and nocturnal. Itis semi-aquatic.

Movements, Home range and Social organization. The species is solitary.

Status and Conservation. Classified as Near Threatened on The IUCN Red List. Despite the large distribution of the Common Crab-eating Rat,this classification is due to pressures on its habitat and the possibility of a species complex. Populations are probably declining due to habitat loss from deforestation and water pollution, but rate of decline does appear to fast enough to qualify for Vulnerable classification.

Bibliography. Brito, Orellana-Vasquez et al. (2015), Musser & Carleton (2005), Soriano & Tirira (2008), Thomas (1924a), Voss (1988, 2015b), Voss et al. (1982), Winge (1891), de Winton (1896).

Figures

321. Groove-toothed Cotton Rat (Sigmodon alstoni), 322. Ecuadorean Cotton Rat (Sigmodon inopinatus), 323. Peruvian Cotton Rat (Sigmodon peruanus), 324. White-eared Cotton Rat (Sigmodon leucotis), 325. Tawny-bellied Cotton Rat (Sigmodon fulviventer), 326. Yellow-nosed Cotton Rat (Sigmodon ochrognathus), 327. Hispid Cotton Rat (Sigmodon hispidus), 328. West Mexican Cotton Rat (Sigmodon mascotensis), 329. Arizona Cotton Rat (Sigmodon arizonae), 330. Toltec Cotton Rat (Sigmodon toltecus), 331. Allen’s Cotton Rat (Sigmodon alleni), 332. Burmeister’s Cotton Rat (Sigmodon hirsutus), 333. Montane Cotton Rat (Sigmodon zanjonensis), 334. Miahuatlan Cotton Rat (Sigmodon planifrons), 335. Musso’s Fish-eating Rat (Neusticomys mussoi), 336. Montane Fish-eating Rat (Neusticomys monticolus), 337. Voss’s Fish-eating Rat (Neusticomys vossi), 338. Venezuelan Fish-eating Rat (Neusticomys venezuelae), 339. Guianan Fish-eating Rat (Neusticomys oyapocki), 340. Ferreira’s Fish-eating Rat (Neusticomys ferreirai), 341. Peruvian Fish-eating Rat (Neusticomys peruviensis), 342. Northern Andean Water Mouse (Chibchanomys trichotis), 343. Orces’s Andean Water Mouse (Chibchanomys orcesi), 344. Earless Water Mouse (Anotomys leander), 345. Pittier’s Crab-eating Rat (Ichthyomys pittieri), 346. Common Crab-eating Rat (Ichthyomys hydrobates), 347. Tweedy’s Crab-eating Rat (Ichthyomys tweedii), 348. Stolzmann’s Crab-eating Rat (Ichthyomys stolzmanni), 349. Goldman's Water Mouse (Rheomys raptor), 350. Thomas's Water Mouse (Rheomys thomasi), 351. Underwood’s Water Mouse (Rheomys underwoodi), 352. Mexican Water Mouse (Rheomys mexicanus)

Subspecies and Distribution. I.h.hydrobatesWinge,1891—WVenezuela. I.h.niceforiThomas,1924—WColombia. I. h. soederstroemi de Winton, 1896 — NC Ecuador.