Muennink's Spiny Rat

Muennink's spiny rat or Okinawa spiny rat (Tokudaia muenninki, Japanese: オキナワトゲネズミ, romanized: Okinawa togenezumi or 沖縄棘鼠) is a species of rodent in the family Muridae. Endemic to Okinawa Island, Japan, its natural habitat is subtropical moist broadleaf forest. The karyotype has 2n = 44. Its sex chromosomes are abnormally large, while the other two species in Tokudaia have lost their Y chromosome. It is found only on the northern part (Yanbaru area) of the island, above 300 m, and is thought to inhabit an area of less than 3 km2. The head and body are up to 7 inches long with a 5-inch tail. They weigh up to 7 ounces. They have a short thick body and dense fur, consisting of fine hairs and coarse, grooved spines (hence the common name "spiny rat"). The fur is brownish above and grayish white below with a faint orange tinge. The spines on the animal's back are black throughout while the...