Animal Diversity Web

Geographic Range

Amazonian red-sided opossums are native to the Amazonian rainforests of Southeast Peru, Brazil and Northern Bolivia and is primarily found near the Southern Amazonian River and west of Xingu River. They have been found in the following states in Brazil: Acre, Rondonia, Amazonas, Mato Grosso and Para. Monodelphis glirina is sympatric in parts of its range with Monodelphis emiliae, Monodelphis brevicaudata and Monodelphis saci. (Castilheiro and Santos Filho, 2013; Pavan, et al., 2014; Pavan, et al., 2017; Pine and Handley,, 2008; Voss, et al., 2012)

• Biogeographic Regions
• neotropical
  • native

Habitat

Amazonian red-sided opossums are terrestrial, semi-fossorial and generally limited to below 1500 m elevation, but have been reported up to 2200 m. Amazonian red-sided opossums are occupy rainforest lowlands and open rainforests near river banks. Trees present in the habitat they occupy include palms Mauritia flexuosa and Jessenia bataua, as well as dominant bamboo species, Guadua sarcocarpa and Gaadua weberbaueri. Specific trees and vegetation used by M. glirina are not yet described. (Anderson, 1997; Daly and Mitchell, 2000; Pavan, et al., 2014; Pine and Handley,, 2008; Vidigal, 2014; Voss, et al., 2012)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• forest
• rainforest

• Range elevation

  0 to 2200 m

  0.00 to 7217.85 ft

Physical Description

The genus Monodelphis is small relative to other species of didelphid opossums. Species in this genus have large claws with a reduced, non-opposable pollex and lack a marsupium and guard hairs. They have wide nasals and premolars that increase in size from front to back, as well as a medial vagina that is elongated anteriorly.

Amazonian red-sided opossums are characterized by longitudinal tricolor pelage patterns with reddish-orange flanks that fade to gray-yellow, although geographical variation occurs among populations. Fur on the tail covers less than 1/6th of the length of the tail. Monodelphis glirina individuals are larger and have sharper contrast of the longitudinal pelage stripes than in the closely related species, Monodelphis sanctaerosae. (Pavan, et al., 2012; Pine and Handley,, 2008; Vidigal, 2014; Voss, et al., 2001; Voss, et al., 2012)

The skull of M. glirina is characterized by incomplete auditory bullae, long and slender palataine foramen, short upper canines and large molars and an intermediate constriction of the interorbital - postorbital region. M. glirina, as well as other species of the M. brevicaudata species complex have elongated maxillopalatine fenestrae, no secondary foramen ovale, less distinct sagital crests and rostral processes, well defined nuchal lines, broad rostrums and triangular stapes with large obturator foramen. Skull measurements for M. glirina specifically are as follows: condylobasal length average: 38.0mm (range 35.7-40.8), nasal length: 18.3mm (16.5-20.6mm), nasal breadth: 5.8mm (5.1-6.4mm), zygomatic breadth: 20.5mm (18.9-22.4mm), least interorbital breadth: 5.9mm (18.9-22.4mm), palatal length: 21.0 mm (19.7-22.3 mm), palatal breadth: 12.5mm (11.7-13.2 mm), maxillary toothrow length: 15.4 mm (15.0-16.0mm), length of molars: 8.1 mm (8.0-8.2mm), length from M1-M3: 6.9mm (6.7-7.0mm), width of M3: 2.8mm (2.7-3.0mm). The Monodelphis brevicaudata species complex is also characterized by dorsal fur approximately 8mm long and shorter, bicolored ventral fur (4mm). In general, M. glirina have orange-red flanks and a gray-orange ventrum. The dorsal pelage is characterized by a gray-brown stripe that fades to the red-orange flanks. The pelage of the head is orange laterally and grey dorsally. Monodelphis glirina can be distinguished from its sister species, M. palliolata, from its upper row of molars that are greater than 7.9 mm length and geographical location. The dental formula for M. glirina has not yet been established, however the general dental formula for opossums is 5/4, 1/1, 3/3, 4/4 = 50. (Kozawa, et al., 1998; Pavan, et al., 2012; Pine and Handley,, 2008)

Populations of Amazonian red-sided opossums occurring in moist forests are more boldly patterned than populations inhabiting mineral crops, with red-orange colored flanks and grey coloring on the middle of the dorsal pelage. Mineral crop-dwelling populations have more pale pelage with less distinct contrast between colors. Species east of the Xingu river lack the characteristic middorsum stripe. (Pavan, et al., 2014)

Amazonian red-sided opossums are sexually dimorphic, with males larger than females. The head-body length of females ranges from 130 to 148 mm, and, in males, it ranges from 138 to 162 mm. Females weigh 49 to 55 g and males weigh 83 to 53 g. Age and reproductive status was not examined in this data set. However, the relative weight and body length differs between the sexes at different age classes in a closely related species, Monodelphis domestica. Females and males were not dimorphic until age class three (of seven observed age classes; age classes undefined). At age class four, males had the same body length as females but were heavier (average weight of males 57 g, females 50 g). By age class five, males were larger than females in all aspects (average male weight and head-body length: 73 g and 144 mm, respectively; average female weight and head-body length: 54 g and 133 mm). (Bergallo and Cerquiera, 1994; Voss, et al., 2012)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• male larger

• Range mass

  24.4 to 79.6 g

  0.86 to 2.81 oz

• Range length

  151.5 to 213.3 mm

  5.96 to 8.40 in

Reproduction

There is insufficient data for on reproduction in M. glirina. However, seasonal breeding is present in Monodelphis dimidiata. Within the genus, there is insufficient data on the mating systems of these opossums. (Bergallo and Cerquiera, 1994; Fadem, et al., 2010; Harder and Jackson, 2010)

The genus Monodelphis contains both iteroparous and semelparous species, although there is no information on this topic for M. glirina. However, generalizations can be made based on closely related species. M. glirina appears to be solitary in the wild, suggesting induced ovulation. In the closely related species, Monodelphis domestica, estrus is induced via contact with the secretions of the suprasternal gland of the males. Females will remain anestrus if the secretions of this gland are not encountered. Females in Monodelphis domestica are capable of producing two litters per breeding season, with 2 to 16 embryos per litter (mean of 7.9), but not all may survive to birth. Gestation is approximately 15 days and implantation occurs on the twelfth day. Divergence of male and female sex organs occurs 4 to 16 days post birth. In a less closely related species, Monodelphis dimidiata, young are weaned at 60 days and reach sexual maturity at 5 to 7 months. Young are altricial, as is typical of marsupials, and first open their eyes around 5 to 6 weeks of age. (Bergallo and Cerquiera, 1994; Fadem, et al., 2010; Harder and Jackson, 2010; Pine, et al., 1985)

• Key Reproductive Features
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• viviparous

• Breeding interval

  Breeding in the closely related species Monodelphis domestica can occur up to two times in a year.

• Breeding season

  Breeding in the closely related species Monodelphis domestica occurs from summer through the end of winter during the rainy season.

• Range number of offspring

  16 (high)

• Average number of offspring

  8-14

• Average gestation period

  15 days

• Average weaning age

  8 weeks

• Average age at sexual or reproductive maturity (female)

  5-7 months

• Average age at sexual or reproductive maturity (male)

  5-7 months

Little parental investment beyond lactation is characteristic of marsupials in general. The extent of parental investment is unknown for Monodelphis glirina. Reproductive investment in the closely related Monodelphis domestica is well-studied. Sexual maturity is reached at 5 to 7 months and young are weaned around 60 days post-birth. Males do not invest in reproduction beyond insemination. (Bergallo and Cerquiera, 1994; Keyte and Smith, 2008)

• Parental Investment
• altricial
• pre-hatching/birth
  • provisioning
    • female
• pre-weaning/fledging
  • provisioning
    • female
• pre-independence
  • provisioning
    • female

Lifespan/Longevity

The closely related Monodelphis domestica has been reported to live to 2.5 to 3 years in captivity. There is no data on the lifespan of Amazonian red-sided opossums in captivity or in the wild. (Keyte and Smith, 2008)

• Average lifespan
  Status: captivity

  2.5-3 years

Behavior

The genus Monodelphis is solitary and has varied activity patterns. There are diurnal, nocturnal and crepuscular species within the genus, and no specific data on activity patterns exists for Amazonian red-sided opossums. Monodelphis species sometimes cannibalize young days after birth and are a good model for research due to their small size and docile nature. These opossums become accustomed to humans quickly. Amazonian red-sided opossums are terrestrial, cursorial, predatory and exhibit moderate-high daily feeding behaviour. Unlike other opossumms, Monodelphis species do not live in trees. (Keyte and Smith, 2008; Pavan, et al., 2014; Pine and Handley,, 2008; Pine, et al., 1985; Steiner and Catzeflis, 2004)

• Key Behaviors
• cursorial
• terricolous
• motile
• solitary

Home Range

There is no data on the home range of Amazonian red-sided opossums.

Communication and Perception

Males and females of the closely related Monodelphis domestica scent mark their environment to communicate with potential mates. Males are perceptive to secretions from skin glands and urine of females and females are only receptive to secretions from the suprasternal gland of males. (Fadem, et al., 2010; Harder and Jackson, 2010)

• Communication Channels
• chemical

• Other Communication Modes
• pheromones
• scent marks

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Amazonian red-sided opossums are opportunistic, generalist omnivores. Insects (primarily beetles, but also grasshoppers and cicadas, true bugs, and millipedes) are a large part of the diet. Seeds and plant material have also been noted in the diet. (Castilheiro and Santos Filho, 2013)

• Primary Diet
• omnivore

• Animal Foods
• insects

• Plant Foods
• seeds, grains, and nuts

Predation

There is no information on predators of Monodelphis species in the literature.

• Anti-predator Adaptations
• cryptic

Ecosystem Roles

Monodelphis species are terrestrial predators that influence insect populations (specifically beetles) via direct predation. Amazonian red-sided opossums are generalist omnivores that have high metabolisms and are likely to modify their habitats through the removal of plants, seeds, and insects. (Anderson, 1997; Castilheiro and Santos Filho, 2013)

The gastrointestinal tract of Amazonian red-sided opossums has been found to contain nematodes in low quantities, indicating a low intensity of parasitism. These parasites are the only recorded parasites of M. glirina, however two ectoparasites were noted on the sister species of M. glirina, Monodelphis palliolata, including a chewing louse and a species of mite. (Castilheiro and Santos Filho, 2013; Pine and Handley,, 2008)

Economic Importance for Humans: Positive

Monodelphis species are used in research on genome sequencing and domestication. They are easy to study due to their small size and docile nature. They are model organisms for studies pertaining to melanoma, spinal cord injury, cholesterol influences on genetics, and olfactory responses to chemicals. (Keyte and Smith, 2008)

• Positive Impacts
• research and education

Economic Importance for Humans: Negative

There are no known adverse effects of M. glirina on humans.

Conservation Status

Amazonian red-sided opossums are listed as Least concern in the IUCN Redlist and have not been evaluated by CITES.

• IUCN Red List

  Least Concern

• US Federal List

  No special status

• CITES

  No special status

Other Comments

Amazonian red-sided opossums were first described by JA Wagner (1842) under the name Didelphis glirina. Some past literature referred to M. glirina as a subspecies of Monodelphis brevicaudata - Monodelphis brevicaudata brevicaudata, due to similar physical descriptions. It is now known that they are genetically distinct from Monodelphis brevicaudata. The Monodelphis brevicaudata species complex includes 7 species: M. brevicaudata, M. glirina, M. domestica, M. palliolata, M. maraxina, M. arlindoi and M. brevicaudata. There is evidence that Monodelphis maraxina may not be its own species, but instead a phenotypic variant of Monodelphis glirina. Cytochrome b sequences suggest that there are at least two different lineages within the species Monodelphis glirina. (Anderson, 1997; Pavan, et al., 2014; Pavan, et al., 2012)

Contributors

Danielle Cayer (author), University of Manitoba, Jane Waterman (editor), University of Manitoba, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

Anderson, S. 1997. Mammals of Bolivia, taxonomy and distribution. New York: Bulletin of the American Museum of Natural History.

Bergallo, H., R. Cerquiera. 1994. Reproduction and growth of the opossum Monodelphis domestica (Mammalia: Didelphidae) in northeastern Brazil. The Journal of Zoology, 32: 551-563.

Caramaschi, F., F. Nascimento, R. Cerqueira, C. Bonvicino. 2011. Genetic diversity of wild populations of the grey short-tailed opossum, Monodelphis domestica (Didelphimorphia: Didelphidae), in Brazilian landscapes. Biological Journal of the Linnean Society, 104: 251-263.

Castilheiro, W., M. Santos Filho. 2013. Diet of Monodelphis glirina (Mammalia: Didelphidae) in forest fragments in southern Amazon. Zoologia, 30 (3): 249-254.

Daly, D., J. Mitchell. 2000. Lowland vegetation of tropical South America. Pp. 391-454 in D Lentz, ed. Imperfect balance: landscape transformations in the precolumbian Americas. New York: Columbia University Press.

Fadem, B., D. Koester, J. Harder. 2010. Perinatal exposure to progesterone, estradiol, or mifepristone affects sexual differentiation of behavior in opossums (Monodelphis domestica). Hormones and Behaviour, 58: 390-396.

Harder, J., L. Jackson. 2010. Chemical Communication and Reproduction in the Gray Short-Tailed Opossum (Monodelphis domestica). Vitamins and Hormones, 83: 373- 399.

Keyte, A., K. Smith. 2008. Opossum (Monodelphis domestica): A Marsupial Development Model. Cold Spring Harbor Protocols, 10: 1-5.

Kozawa, Y., Y. Iwasa, H. Mishima. 1998. Degeneration of tooth germ in the developing dentition of the gray short-tailed opossum (Monodelphis domestica). European Journal of Oral Sciences, 106: 509-512.

Lim, B., M. Engstrom, J. Patton, J. Bickham. 2010. Molecular phylogenetics of Reig’s short-tailed opossum (Monodelphis reigi) and its distributional range extension into Guyana. Mammalian Biology, 4: 287-293.

Pavan, S., A. Mendes-Oliveira, R. Voss. 2017. A New Species of Monodelphis (Didelphimorphia: Didelphidae) from the Brazilian Amazon. American Museum Novitates, 3872: 1-20.

Pavan, S., R. Rossi, H. Schneider. 2012. Species diversity in the Monodelphis brevicaudata complex (Didelphimorphia: Didelphidae) inferred from molecular and morphological data, with the description of a new species. Zoological Journal of the Linnean Society, 165: 190-223.

Pavan, S., S. Jansa, R. Voss. 2014. Molecular phylogeny of short-tailed opossums (Didelphidae: Monodelphis): Taxonomic implications and tests of evolutionary hypotheses. Molecular Phylogenetics and Evolution, 79: 199-214.

Pine, R., P. Dalby, J. Matson. 1985. Ecology, Postnatal Development, Morphometrics, and Taxonomic Status of the Short-tailed Oppossum, Monodelphis Dimidiata, an Apparently Semelparous Annual Marsupial.. Pittsburgh, Pennsylvania: Annals of Carnegie Museum.

Pine, R., C. Handley,. 2008. Genus Monodelphis Burnett, 1830. Mammals of South America, 1: 82-107.

Steiner, C., F. Catzeflis. 2004. Genetic Variation and Geographical Structure of Five Mouse-Sized Opossums (Marsupialia, Didelphidae) throughout the Guiana Region. Journal of Biogeography, 31: 959-973.

Ventura, J., R. Perez-Hernandez, M. Lopez-Fuster. 1998. Morphometric Assessment of the Monodelphis brevicaudata Group (Didelphimorphia: Didelphidae) in Venezuela. Journal of Mammology, 79 (1): 104-117.

Vidigal, V. 2014. Studies on the genealogical relationships within the genus Monodelphis Burnett, 1830 (Didelphidae, Marsupialia) based on basicranial anatomy and external morphology. Barcelona: Universitat de Barcelona.

Voss, R., D. Lunde, N. Simmons. 2001. THE MAMMALS OF PARACOU, FRENCH GUIANA: A NEOTROPICAL LOWLAND RAINFOREST FAUNA PART 2. NONVOLANT SPECIES. Bulletin of the American Museum of Natural History, 263: 3-237. Accessed November 10, 2017 at http://www.bioone.org/doi/full/10.1206/0003-0090%282001%29263%3C0003%3ATMOPFG %3E2.0.CO%3B2.

Voss, R., R. Pine, S. Salari. 2012. A New Species of the Didelphid Marsupial Genus Monodelphis from Eastern Bolivia. American Museum Novitates, 3740: 1-14.