Muennink's spiny rat

Muennink's spiny rat
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Family: Muridae
Genus: Tokudaia
Species:
T. muenninki
Binomial name
Tokudaia muenninki
(Johnson, 1946)

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.[2] Endemic to Okinawa Island, Japan, its natural habitat is subtropical moist broadleaf forest. The karyotype has 2n = 44.[2] Its sex chromosomes are abnormally large, while the other two species in Tokudaia have lost their Y chromosome.[3] It is found only on the northern part (Yanbaru area) of the island, above 300 m,[1] and is thought to inhabit an area of less than 3 km2.[4]

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 spines underneath are usually white with a reddish-brown tip. The spines cover the body except for the regions around the mouth, ears, feet and tail. The tail is bi-colored for its entire length.[5]

The species is threatened by deforestation, predation by feral cats and introduced mongooses, and competition with introduced black rats.[1] In March 2008, the first wild specimen in over 30 years was caught in the northern part of Okinawa.[6]

  1. ^ a b c Ishii, N. (2016). "Tokudaia muenninki". IUCN Red List of Threatened Species. 2016: e.T21972A22409515. doi:10.2305/IUCN.UK.2016-1.RLTS.T21972A22409515.en. Retrieved 13 November 2021.
  2. ^ a b Musser, G. G.; Carleton, M. D. (2005). "Superfamily Muroidea". In Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 1512–1513. ISBN 978-0-8018-8221-0. OCLC 62265494.
  3. ^ Murata, C.; Yamada, F.; Kawauchi, N.; Matsuda, Y.; Kuroiwa, A. (2011-12-24). "The Y chromosome of the Okinawa spiny rat, Tokudaia muenninki, was rescued through fusion with an autosome". Chromosome Research. 20 (1): 111–125. doi:10.1007/s10577-011-9268-6. PMID 22198613. Free access icon
  4. ^ "Okinawa Spiny Rat". EDGE of Existence.
  5. ^ "EDGE of Existence". EDGE of Existence. Retrieved 2017-03-02.
  6. ^ "幻のネズミ、30年ぶり捕獲 沖縄北部の絶滅危惧種". Archived from the original on 2008-03-09. Retrieved 2008-03-09.