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

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

, restricted to north-eastern

Bahia Bahia () 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 (state), São Paulo, Mina ...

in eastern Brazil. It is the only species in the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

''Callistomys''.

Identification

With a total length of ca. , 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 inst ...

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 classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

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

superlative The degrees of comparison of adjectives and adverbs are the various forms taken by adjectives and adverbs when used to compare two entities (comparative degree), three or more entities (superlative degree), or when not comparing entities (positi ...

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 languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

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. It also occurs in cocoa plantations where some native trees remain. As far as known, it is

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

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 Echimyidae, 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 Unive ...

''. 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 ''Proechimys'' is a genus of South American South America is a contine ...

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, inv ...

by the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

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 Myocastorini Mammals described in 1841 Taxa named by François Jules Pictet de la Rive Rodents of Brazil