Muennink's spiny rat

Muennink's spiny rat, Tokudaia muenninki, also called the Okinawa spiny rat, is a rodent in the family Muridae endemic to Okinawa Island, Japan. It is found only in the northern Yanbaru area of the island above 300 metres, in subtropical moist broadleaf forest, and is thought to occupy an area of less than 3 square kilometres. It has a short thick body with dense fur made of fine hairs and coarse grooved spines, brownish above and grayish white below with a faint orange tinge, and a bi-coloured tail. Its karyotype is 2n = 44 and its sex chromosomes are abnormally large, whereas the other two Tokudaia species have lost their Y chromosome. Deforestation, predation by feral cats and introduced mongooses, and competition with introduced black rats threaten it, and in March 2008 the first wild specimen in over 30 years was caught in northern Okinawa.