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 ; vibrations ; chemical
Thylamys velutinus is currently listed under "Least Concern" on the IUCN Red List.
IUCN Red List of Threatened Species: least concern
CITES: no special status
There are no known negative effects of Thylamys velutinus.
There are no known positive impacts of Thylamys velutinus on humans.
Thylamys velutinus 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 velutinus is not presently available.
Little is known about the food habits of this species. Like other Thylamys species, Thylamys velutinus likely consumes insects and perhaps occasionally eats small vertebrates, leaves, fruit, seeds, and carrion (Palma 1997).
Primary Diet: carnivore (Insectivore )
Thylamys velutinus occurs south of the Amazon Rainforest in the Brazilian states of Goiás, Minas Gerais, and São Paulo and the Distrito Federal (Carmignotto and Monfort 2006).
Biogeographic Regions: neotropical (Native )
Thylamys velutinus has been collected in the Cerrado (tropical savanna) ecoregion of Brazil. Like most other Thylamys species, T. velutinus appears to prefer open-canopy habitats instead of closed canopy forests.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: savanna or grassland
The lifespan of this species is not known.
Like other members of its genus, Thylamys velutinus 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 bicolored, with darker dorsal fur and a gray ventral region. This species can be distinguished from its closest relative, Thylamys karimii, by gray hairs on its ventral region (as opposed to fully white hairs in T. karimii). Carmignotto and Monfort (2006) report head and body lengths that range from 79 to 110 mm (average 98 mm), tail lengths that range from 65 to 91 mm long (average 78 mm), and body weights that range from 13 to 35 g (average 24 g).
Range mass: 13 to 35 g.
Range length: 144 to 201 mm.
Average length: 176 mm.
Other Physical Features: endothermic ; bilateral symmetry
Like other small mammals, Thylamys velutinus is likely well adapted to avoiding predators by being nocturnal and inconspicuous. No records of known predators are available.
Anti-predator Adaptations: cryptic
No published studies have examined mating systems in Thylamys velutinus. However, Carmignotto and Monfort (2006) captured juvenile Thylamys karmii individuals (the closest relative to T. velutinus) in both the wet and dry season, which suggests that these species might breed year-round.
Little is known about the reproductive behavior of Thylamys velutinus.
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Little is known about parental investment in Thylamys velutinus. 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)
The dwarf fat-tailed mouse opossum (Thylamys velutinus), also known as the velvety fat-tailed opossum is an opossum species from South America. It is endemic to Brazil, where it is found in cerrado and caatinga habitats.[2] Its head-and-body length is about 141-212 (average 173.3) mm, and its tail length is about 73-85 (average 78) mm. Its diet is 44% arthropods; 75% of its diet consists of animals and animal products.[3] Its ventral fur is entirely gray-based. Its hind foot is less than 14 mm, which is short for the genus.[4]
The dwarf fat-tailed mouse opossum (Thylamys velutinus), also known as the velvety fat-tailed opossum is an opossum species from South America. It is endemic to Brazil, where it is found in cerrado and caatinga habitats. Its head-and-body length is about 141-212 (average 173.3) mm, and its tail length is about 73-85 (average 78) mm. Its diet is 44% arthropods; 75% of its diet consists of animals and animal products. Its ventral fur is entirely gray-based. Its hind foot is less than 14 mm, which is short for the genus.
