Tome's spiny rat

Tome's spiny rat is a large rat with a head-and-body length of between {{convert|220|and|280|mm|in|1|abbr=on}} and a tail length of between {{convert|175|and|192|mm|in|1|abbr=on}}. The head is long and slender, with prominent eyes and narrow erect ears. At night, the eyes reflect a reddish eyeshine. The feet are long with strong nails. The pelage is sleek with spines mixed in with the dorsal fur, though these are not very obvious in the field. The upper parts are reddish-brown while the underparts are white. The tail is almost hairless and is reddish-brown above and white below. About 20% of animals encountered have no tail. This rat could be confused with the armored rat (Hoplomys gymnurus) which is much the same size, but the armored rat has a longer snout and smaller eyes, which are less reflective at night. Other terrestrial rats are considerably smaller and mostly have tails that are longer than their head-and-body lengths.{{cite book|author=Reid, Fiona|title=A Field Guide to the Mammals of Central America and Southeast Mexico |url=https://books.google.com/books?id=aBEbUaXTWYAC&pg=PA251 |year=2009 |publisher=OUP USA |isbn=978-0-19-534322-9 |page=251}}

Its karyotype has 2n = 30 and FN = 50-54.{{MSW3 Hystricognathi | id = 13400504| page = 1588 | heading = Species Proechimys semispinosus}}

The range of Tome's spiny rat extends from southeastern Honduras to southwestern Ecuador and possibly to northern Peru. It generally keeps below {{convert|800|m|ft|-1|abbr=on}} but in Ecuador may be found a little higher. It is a common species in evergreen and deciduous forest, favouring riparian corridors and low-lying areas. It is a tolerant and adaptable species, and the International Union for Conservation of Nature has assessed its conservation status as being of "least concern".

Tome's spiny rat is a nocturnal, mainly ground-dwelling rat. During the day it may hide in a burrow or under a fallen tree, in a hollow log or in dense vegetation. At night it moves slowly and often sits stationary beside a tree buttress or log. It may freeze if caught in the open. It feeds on fruits and seeds, fungi, plant material and insects, carrying larger objects to a safe place before consuming them. The females can breed four times a year, producing litters of up to five precocial young. The reproductive rate seems to be limited by the availability of food. On a group of small islands in Panama, each of which had its own range of tree species which fruited at different seasons, there were few births on each islet at times of fruit shortage and many at times of fruit abundance; the seasonal effects were even more marked when the spiny rat was the only frugivorous mammal on the island.{{cite book|author=Leigh, Egbert Giles|title=Tropical Forest Ecology: A View from Barro Colorado Island |url=https://books.google.com/books?id=1knnCwAAQBAJ&pg=PA28 |year=1999 |publisher=Oxford University Press |isbn=978-0-19-509603-3 |page=28}}

Morphological characters and mitochondrial cytochrome b DNA sequences showed that P. semispinosus belongs to the so-called semispinosus group of Proechimys species, and shares closer phylogenetic affinities with the other member of this clade: P. oconnelli.{{Cite journal | last=Patton | first=James L. | author-link=James L. Patton | date=1987 | title=Species groups of spiny rats, genus Proechimys (Rodentia: Echimyidae) | pages=305–345 | url=https://www.biodiversitylibrary.org/part/9267 | journal=Fieldiana: Zoology, Studies in Neotropical Mammalogy: Essays in Honor of Philip Hershkovitz | language=English | volume=39 | issn=0015-0754}}{{Cite journal | last=Da Silva | first=Maria Nazareth F. | author-link=Maria Nazareth F. da Silva | date=1998 | title=Four New species of spiny rats of the genus Proechimys (Rodentia : Echimyidae) from the Western Amazon of Brazil | url=http://biostor.org/reference/81093 | journal=Proceedings of the Biological Society of Washington | language=en | volume=111 | pages=436–471 | issn=0006-324X}}{{Cite book | last1=Patton | first1=James L. | author-link=James L. Patton | last2=Leite | first2=Rafael N. | chapter=Genus Proechimys J. A. Allen, 1899 | pages=950–989 | title=Mammals of South America, Volume 2: Rodents | editor-last=Patton | editor-first=James L. | editor-last2=Pardiñas | editor-first2=Ulyses F. J. | editor-last3=D’Elía | editor-first3=Guillermo | date=2015-03-09 | publisher=University of Chicago Press | isbn=9780226169606 | language=en | chapter-url=https://books.google.com/books?id=mbjnBgAAQBAJ}}

{{cladogram

|title=Species-level cladogram of the genus Proechimys.

|caption=The cladogram has been reconstructed from morphological characters and mitochondrial DNA (cytochrome b) sequences.{{Cite journal | last1=Patton | first1=James L. | author-link=James L. Patton | last2=Da Silva | first2=Maria Nazareth F. | author-link2=Maria Nazareth F. da Silva | last3=Malcolm | first3=Jay R. | date=2000-01-01 | title=Mammals of the Rio Juruá and the evolutionary and ecological diversification of Amazonia | journal=Bulletin of the American Museum of Natural History | volume=244 | pages=1–306 | doi = 10.1206/0003-0090(2000)244<0001:MOTRJA>2.0.CO;2 | s2cid=85577629 | issn=0003-0090 | doi-access=free }}

|align=center

|clades={{Cladogram of Proechimys species}}

}}

Tome's spiny rat can serve as a reservoir species for the trypanosomes that are responsible for the disease leishmaniasis, which is spread by sandflies and affects humans. The rat can be infected and harbour the parasite without showing clinical signs of the disease.{{cite journal |author=Travi, B.L. |author2=Arteaga, L.T. |author3=Leon, A.P. |author4=Adler. G.H. |year=2002 |title=Susceptibility of spiny rats (Proechimys semispinosus) to Leishmania (Viannia) panamensis and Leishmania (Leishmania) chagasi |journal=Memórias do Instituto Oswaldo Cruz |volume=97 |issue=6 |pages=887–892 |doi= 10.1590/S0074-02762002000600025 |pmid= 12386716|doi-access=free }}

It also hosts the virus Thurisazvirus myis.{{cite journal | vauthors = Paraskevopoulou S, Pirzer F, Goldmann N, Schmid J, Corman VM, Gottula LT, Schroeder S, Rasche A, Muth D, Drexler JF, Heni AC, Eibner GJ, Page RA, Jones TC, Müller MA, Sommer S, Glebe D, Drosten C | display-authors = 6 | title = Proechimys semispinosus | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 117 | issue = 30 | date = July 2020 | pages = 17977–17983 | pmid = 32651267 | doi = 10.1073/pnas.2006750117 | pmc = 7395443 | doi-access = free }}

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• {{Wikispecies-inline|Proechimys semispinosus|Proechimys semispinosus}}

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{{Taxonbar|from=Q1768762}}

Category:Proechimys

Category:Mammals of Colombia

Category:Rodents of Central America

Category:Mammals described in 1860

Category:Taxa named by Robert Fisher Tomes