The Ryukyu spiny rat (''Tokudaia osimensis'') is a species of rodent in the family

Muridae The Muridae, or murids, are the largest family of rodents and of mammals, containing approximately 1,383 species, including many species of mice, rats, and gerbils found naturally throughout Eurasia, Africa, and Australia. The name Muridae come ...

. Endemic to Amami Ōshima island in the Amami Islands of the Ryukyu archipelago of

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

, its natural habitat is

subtropical moist broadleaf forest Tropical and subtropical moist broadleaf forests (TSMF), also known as tropical moist forest, is a subtropical and tropical forest habitat type defined by the World Wide Fund for Nature. Description TSMF is generally found in large, discont ...

. The

karyotype A karyotype is the general appearance of the complete set of metaphase chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is disce ...

has an odd

diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...

number, 2n = 25. Like its relative '' T. tokunoshimensis'', it has lost its Y chromosome and ''SRY'' gene. The species is threatened by habitat destruction and

fragmentation Fragmentation or fragmented may refer to: Computers * Fragmentation (computing), a phenomenon of computer storage * File system fragmentation, the tendency of a file system to lay out the contents of files non-continuously * Fragmented distributi ...

, predation by feral cats and dogs and introduced mongooses, and competition with introduced

black rat The black rat (''Rattus rattus''), also known as the roof rat, ship rat, or house rat, is a common long-tailed rodent of the stereotypical rat genus ''Rattus'', in the subfamily Murinae. It likely originated in the Indian subcontinent, but is n ...

References

Y-chromosome - Will it or will it not, hold on?
Rats of Asia Endemic mammals of Japan Endemic fauna of the Ryukyu Islands Endangered fauna of Asia Tokudaia Mammals described in 1934 Taxonomy articles created by Polbot {{Murinae-stub

See also

References