Chimarrogale platycephala (Temminck, 1842)

Russell A. Mittermeier & Don E. Wilson, 2018, Soricidae, Handbook of the Mammals of the World – Volume 8 Insectivores, Sloths and Colugos, Barcelona: Lynx Edicions, pp. 332-551 : 455-456

177.

Japanese Water Shrew

Chimarrogale platycephala

French: Chimarrogale du Japon / German: Japanische Wasserspitzmaus / Spanish: Musgano de Japon

Other common names: Flat-headed Water Shrew

Taxonomy. Sorex platycephalus Temminck, 1842 ,

near Nagasaki and Bungo, Kyushu , Japan.

Widely used specific name platycephalus has been changed for gender agreement. Monotypic.

Distribution. Endemic to Japan, widely distributed on Honshu and Kyushu. No recent records of extant distribution but fossil records found on Shikoku.

Descriptive notes. Head-body 112-135 mm, tail 82-110 mm, hindfoot 23-28 mm; weight 37-55 g. Condylo-incisive lengths are 25-28-4 mm, and tooth rows are 12-12-8 mm. The Japanese Water Shrew is the largest species of Chimarrogale , with long tail but shorter than head-body length. In summer, dorsal pelage is grayish black, venter is mouse gray to olive buff; in winter, dorsal pelage is blackish brown, and venter is whitish. Dorsal and lateral pelage is scattered with guard hairs, especially on rump. Tail is bicolored, being blackish brown above and white below. Braincase is flattened and broad, being flattened and enlarged in lateral view. Tips of teeth are usually unpigmented but sometimes covered with pale brown pigment. There are three upper unicuspids. Chromosomal complement has 2n = 52 and FNa = 100.

Habitat. Swift streams or riversides in mountain forests. The Japanese Water Shrew prefers habitats with abundant shelter on riverbanks such as boulders, large rocks or logs with underside cavities orslits, and water-eroded cavities. It occurs at elevations of under 100 m to at least 1000 m, but are most common at 500-1000 m.

Food and Feeding. Diet of the Japanese Water Shrew includes aquatic insects, small fish, frogs, salamanders, snails, crayfish, crabs, earthworms, leeches, and spiders.

Breeding. The Japanese Water Shrew has two breeding seasons: February—June and October-December. Average number of embryos is 4-2/female (range 1-6). A breeding nest constructed underground with broadleaves has been reported. Longevity is more than three years based on a field survey and examination of museum specimens.

Activity patterns. The Japanese Water Shrew is active day and night. It has been reported that it has multiple activity cycles in a day. It is adapted to swim and dive; it uses riverbanks to move up streams and rivers.

Movements, Home range and Social organization. Based on trapping data, home ranges were 300-600 m in length along a stream orriver.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Most habitats important to the Japanese Water Shrew have been preserved and protected. It is sometimes considered as a pest at fish farms in mountain areas. Typhoons and resulting flooding and habitat loss can be serious threats to this species.

Bibliography. Abe (2003), Ohdachi et al. (2009).

Figures

136. Elliot’s Short-tailed Shrew (Blarina hulophaga), 137. Northern Short-tailed Shrew (Blarina brevicaudus), 138. Southern Short-tailed Shrew (Blarina carolinensis), 139. Everglades Short-tailed Shrew (Blarina peninsulae), 140. Sherman’s Short-tailed Shrew (Blarina shermani), 141. Sichuan Short-tailed Shrew (Blarinella quadraticauda), 142. Burmese Short-tailed Shrew (Blarinella wardi), 143. Indochinese Short-tailed Shrew (Blarinella griselda), 144. Chinese Mole Shrew (Anourosorex squamaipes), 145. Taiwanese Mole Shrew (Anowrosorex yamashinai), 146. Assam Mole Shrew (Anowrosorex assamensis), 147. Giant Mole Shrew (Anourosorex schmid), 148. Desert Gray Shrew (Notiosorex crawfordi), 149. Cockrum’s Gray Shrew (Notiosorex cockrumi), 150. Large-eared Gray Shrew (Notiosorex evolis), 151. Villa’s Gray Shrew (Notiosorex villa), 152. Mexican Shrew (Megasorex gigas), 153. Taiwanese Brown-toothed (Shrew Epusoriculusfumidus), 154. Arboreal Brown-toothed Shrew (Episoriculus macrurus), 155. Bailey's Brown-toothed Shrew (Episoriculus baileyi), 156. Long-tailed Brown-toothed Shrew (Episoriculus leucops), 157. Hodgson’s Brown-toothed Shrew (Episoriculus caudatus), 158. Sichuan Brown-toothed Shrew (Episoriculus sacratus), 159. Hidden Brown-toothed Shrew (Episoriculus umbrinus), 160. Nepalese Brown-toothed Shrew (Episoriculus soluensis), 161. Himalayan Shrew (Soriculus nigrescens), 162. De Winton’s Brown-toothed Shrew (Chodsigoa hypsibia), 163. Pygmy Brown-toothed Shrew (Chodsigoa parva), 164. Smith’s Brown-toothed Shrew (Chodsigoa smithii), 165. Salenski’s Brown-toothed Shrew (Chodsigoa salenskii), 166. Dusky Brown-toothed Shrew (Chodsigoa furva), 167. Lesser Taiwanese Brown-toothed Shrew (Chodsigoa sodalis), 168. Van Sung’s Brown-toothed Shrew (Chodsigoa caovansunga), 169. Hoffmann’s Brown-toothed Shrew (Chodsigoa hoffmanni), 170. Lowe’s Brown-toothed Shrew (Chodsigoa parca), 171. Bornean Water Shrew (Chimarrogale phaeura), 172. Sumatran Water Shrew (Chimarrogale sumatrana), 173. Malayan Water Shrew (Chimarrogale hantu), 174. Chinese Water Shrew (Chimarrogale styani), 175. Himalayan Water Shrew (Chimarrogale himalayica), 176. Leander’s Water Shrew (Chimarrogale leander), 177. Japanese Water Shrew (Chimarrogale platycephala), 178. Elegant Water Shrew (Nectogale elegans), 179. Mediterranean Water Shrew (Neomys anomalus), 180. Transcaucasian Water (Shrew Neomysteres), 181. Eurasian Water Shrew (Neomys fodiens)

Distribution. Endemic to Japan, widely distributed on Honshu and Kyushu. No recent records of extant distribution but fossil records found on Shikoku.