Because this species is small and nocturnal, communication between individuals is likely primarily olfactory in nature. Palma (1997) reports that the olfactory and visual regions of another Thylamys species' brain are especially well developed.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
Thylamys karimii is listed as "Vulnerable" according to the IUCN Red List due to habitat destruction in the Brazilian Cerrado and Caatinga.
IUCN Red List of Threatened Species: vulnerable
There are no known negative effects of Thylamys karimii.
There are no known positive impacts of Thylamys karimii.
Thylamys karimii likely acts as an important predator to many arthropod species and perhaps some small vertebrates. It is likely prey to both bird and medium-sized mammals, such as owls and foxes. It is also likely host to many ecto- and endoparasites. More specific information about the ecosystem role of Thylamys karimii is not presently available.
Little is known about the food habits of this species. Like other Thylamys species, Thylamys karimii likely consumes insects and perhaps occasionally eats small vertebrates, leaves, fruit, seeds, and carrion (Palma 1997).
Animal Foods: carrion ; insects; terrestrial non-insect arthropods
Plant Foods: leaves; seeds, grains, and nuts; fruit
Primary Diet: carnivore (Insectivore )
Thylamys karimii occurs south of the Amazonian rainforest in the Brazilian states of Bahia, Goiás, Mato Grosso, Minas Gerais, Pernambuco, Piauí, Rondônia, and Tocantins (Carmignotto and Monfort 2006).
Biogeographic Regions: neotropical (Native )
Thylamys karimii has been collected in both the Cerrado (tropical savanna) and Caatinga (semi-arid shrubland) ecoregions of Brazil. Like most other Thylamys species, T. karimii appears to prefer open-canopy habitats instead of closed canopy forests.
Range elevation: 342 to 1171 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: savanna or grassland ; scrub forest
The lifespan of this species is not known.
Like other members of its genus, Thylamys karimii is notable for its incrassate (fattened) tail. The size of the tail varies by season in accordance with food availability. Although this species is a marsupial, females do not have a pouch. This species is tricolored, with darker dorsal fur, paler lateral fur, and a white ventral region (though some individuals might not obviously display this pattern; Carmignotto and Monfort, 2006). This species can be distinguished from its closest relative, Thylamys velutinus, by fully white hairs on its ventral region (as opposed to gray-based hairs in T. velutinus). Carmignotto and Monfort (2006) report head + body lengths that range from 78 to 129 mm (average 104 mm), tail lengths that range from 69 to 106 mm long (average 80 mm), and body weights that range from 16 to 43 g (average 28 g). Carmignotto and Monfort (2006) also observed weak sexual dimorphism in several cranio-dental characters and pelage characters, but only among adults.
Range mass: 16 to 43 g.
Average mass: 28 g.
Range length: 147 to 235 mm.
Average length: 184 mm.
Sexual Dimorphism: sexes colored or patterned differently; sexes shaped differently
Other Physical Features: endothermic ; bilateral symmetry
Like other small mammals, Thylamys karimii is likely well adapted to avoiding predators by being nocturnal and inconspicuous. No records of known predators are available.
Anti-predator Adaptations: cryptic
Carmignotto and Monfort (2006) captured juvenile Thylamys karmii individuals in both the wet and dry season, which suggests that this species might breed year-round. However, little is known about any other aspect of this species' reproduction.
Little is known about the reproductive behavior of Thylamys karimii.
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Little is known about parental investment in Thylamys karimii. Like all marsupials, females nurse their highly altricial young. However, because members of the genus Thylamys lack a pouch (marsupium), the young must cling to their mother's venter.
Parental Investment: altricial ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
Karimi's fat-tailed mouse opossum (Thylamys karimii) is a species of opossum in the family Didelphidae.[2] It is endemic to central and northeast Brazil, where it is found in the cerrado and caatinga at elevations from 300 to 1100 m.[1] This opossum is crepuscular and mostly terrestrial; its omnivorous diet includes leaves, insects and small vertebrates.[1] Its head-and-body length is about 95 millimeters, and its tail length is about 72 millimeters. It is very similar to T. pallidor. Its tail may be nonprehensile.[3] The species is named after Iranian epidemiologist Y. Karimi.[4] It is threatened by habitat destruction and fragmentation due to agriculture and ranching.[1]
Karimi's fat-tailed mouse opossum (Thylamys karimii) is a species of opossum in the family Didelphidae. It is endemic to central and northeast Brazil, where it is found in the cerrado and caatinga at elevations from 300 to 1100 m. This opossum is crepuscular and mostly terrestrial; its omnivorous diet includes leaves, insects and small vertebrates. Its head-and-body length is about 95 millimeters, and its tail length is about 72 millimeters. It is very similar to T. pallidor. Its tail may be nonprehensile. The species is named after Iranian epidemiologist Y. Karimi. It is threatened by habitat destruction and fragmentation due to agriculture and ranching.
