The painted tree-rat (''Callistomys pictus'') is a species of spiny rat from

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

, restricted to north-eastern

Bahia Bahia ( , , ; meaning "bay") is one of the 26 Federative units of Brazil, states of Brazil, located in the Northeast Region, Brazil, Northeast Region of the country. It is the fourth-largest Brazilian state by population (after São Paulo (sta ...

in eastern Brazil. It is the only species in the genus ''Callistomys''.

Identification

With a total length of ca. 30 cm (12 in), it is a relatively large species of spiny rat. It is white with a strongly contrasting glossy-black cap, back and band down towards its

forelimb A forelimb or front limb is one of the paired articulated appendages (limbs) attached on the cranial ( anterior) end of a terrestrial tetrapod vertebrate's torso. With reference to quadrupeds, the term foreleg or front leg is often used instead. ...

s. Its long fur is dense and coarse, but not spiny, as in some other members of its family. Specimens often have brown (rather than black) markings, but as far as it is known this is caused by fading and does not occur in the living animals. Owing to its striking black-and-white pelage, it is virtually unmistakable, but could perhaps be confused with a hairy dwarf porcupine ('' Coendou spp.'') – all of which have spines and lack the distinctive pattern of the painted tree-rat.

Etymology

* The genus name ''Callistomys'' derives from the two

ancient greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

words () meaning "very beautiful", — i.e., this is the

superlative Comparison is a feature in the morphology or syntax of some languages whereby adjectives and adverbs are inflected to indicate the relative degree of the property they define exhibited by the word or phrase they modify or describe. In languages t ...

form of () meaning "beautiful, handsome" —, and (), meaning "rat". * The species name derives from the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

word ''pictus'' meaning ''colored, decorated'', and refers to the white and black fur of this rodent.

Habitat

The painted tree-rat is found in the

Atlantic forest The Atlantic Forest ( pt, Mata Atlântica) is a South American forest that extends along the Atlantic coast of Brazil from Rio Grande do Norte state in the northeast to Rio Grande do Sul state in the south and inland as far as Paraguay and th ...

. It also occurs in

cocoa Cocoa may refer to: Chocolate * Chocolate * ''Theobroma cacao'', the cocoa tree * Cocoa bean, seed of ''Theobroma cacao'' * Chocolate liquor, or cocoa liquor, pure, liquid chocolate extracted from the cocoa bean, including both cocoa butter and ...

plantations where some native trees remain. As far as known, it is

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

Phylogeny

The painted tree-rat has been placed in different genera: '' Nelomys'', '' Loncheres'', or ''

Isothrix The toros or brush-tailed rats, genus ''Isothrix'', are a group of spiny rats found in tropical South America, particularly in the Amazon Basin.Nowak, Ronald M. 1999. ''Walker's Mammals of the World'', 6th edition. Johns Hopkins University Pres ...

''. However, analyses of DNA and protein characters showed that the genus ''Callistomys'' is the sister group to the genus ''Myocastor'' (coypus or nutrias). In turn, these two taxa share evolutionary affinities with other

Myocastorini Myocastorini is a tribe of echimyid rodents, proposed in 2017, and containing the five extant genera ''Callistomys'', ''Hoplomys'', ''Myocastor'', ''Proechimys'', and ''Thrichomys ''Thrichomys'' is a genus of South American rodents in the fam ...

genera: ''Proechimys'' and ''Hoplomys'' (armored rats) on the one hand, and ''Thrichomys'' on the other hand.

Conservation status

The painted tree-rat is currently listed as

Endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...

by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

because of its fragmented distribution, its continuing decline and the quality of its habitat. An outlying record was not included in the assessment.

References

External links

ARKive: Images and movies of the Painted tree-rat (''Callistomys pictus'')
{{Taxonbar, from=Q302775 Echimyidae Mammals described in 1841 Taxa named by François Jules Pictet de la Rive