The family Didelphidae is split into two subfamilies, the Didelphinae and the Caluromyinae. The black-shouldered opossum belongs the the subfamily Caluromyinae (Macdonald 1987).
Perception Channels: tactile ; chemical
Caluromysiops irrupta is considered the rarest of the larger didelphids, however, no special status concern has been legislated for this species (Izor and Pine 1987).
IUCN Red List of Threatened Species: least concern
Black-shouldered opossums can act as pollinators and thus aid the dispersal of seeds (Izor and Pine 1987).
Black-shouldered opossums climb through trees in search of fruit in humid tropical forests and exploit nectar of flowering trees during the dry seasons. Due to their nectarivorous behaviour, they can serve as pollinators for those trees they visit. Some cranial features of Caluromysiops, such as the pronounced sagittal crest and the robust, outward bowing zygomatic arches, suggest it is adapted to biting hard substances such as nuts (Izor and Pine, 1987).
Humid Andean forests of South America.
Biogeographic Regions: neotropical (Native )
Black-shouldered opossum is highly arboreal and inhabits humid forests (Nowak 1991).
Terrestrial Biomes: rainforest
Average lifespan
Status: captivity: 7.8 years.
Caluromysiops irrupta has a head and body length of 25-30 cm and tail length of 31-33 cm. Its most distinguishing features are the two separate, black lines on the upper part of the body. These black lines begin on the forefeet and run onto the back, join on the shoulders, then separate again and run parallel to each other down the back and over the rump to the hind limbs. There are also faint lines that run through the eyes and along the middle of the belly with the underpart grayish in color (Walker 1975). The tail of Caluromysiops has dense, long and woolly fur, but the underside of the last three-fourths of the tail is naked. Also, the basal three-quarters of the tail on the upper side has a darker shade of gray than the body, and the last quarter of the tail is creamy white. The tail has 30-31 vertebrae and is prehensile, allowing the animal to use it for clinging to branches with the tail while reaching for food. In addition, the hind limbs of Caluromysiops are relatively shorter than the forelimbs (Izor and Pine 1987).
The skull of Caluromysiops also has some distinct features. The eyes are large and protruding (a characteristic of tree-dwellers), the sagittal crest is pronounced in adults, the zygomatic arches are robust, the rostrum is short, the mandible is deep and the molars are relatively larger (a distinctive feature in Calurymysiops). The dental formula conforms to that of other didelphids is 5/4, 1/1, 4/4, 3/3. It posseses five cusps that are usually high and palatal fenestrae that are closed (Izor and Pine 1987).
Average mass: 250 g.
Other Physical Features: endothermic ; bilateral symmetry
Reproduction in Caluromysiops is typical of the marsupials. The gestation period is short, ranging from 12-14 days. A female will often produce more young than the number of mammae available and has a tendency to lick the pouch area before birth. Little is known of the reproduction of this species. Its pattern is probably similar to that of other didelphids. In general, in this family young at birth are very small and are not as fully developed as the young of placentals. The time from birth to weaning in didelphids ranges from 110 to 125 days. (Macdonald1987).
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average number of offspring: 2.
The black-shouldered opossum (Caluromysiops irrupta), also known as the white-eared opossum, is an opossum known from western Brazil and southeastern Peru. It was first described by Colin Campbell Sanborn, curator of Field Museum of Natural History, in 1951. The black-shouldered opossum is characterized by a gray coat, gray underbelly, and broad black stripes that extend from the forefeet, meet on the shoulders, run along the midline of the back and then split into parallel stripes that run down the hind feet. Little is known of the behavior of the black-shouldered opossum. It is nocturnal and arboreal. It is known to feed on fruits and rodents. The opossum inhabits humid forests. The IUCN classifies it as least concern.
The black-shouldered opossum is the sole member of Caluromysiops, and is placed in the family Didelphidae.[2] No subspecies are recognized.[3]
The cladogram below, based on a 2016 study, shows the phylogenetic relationships of the brown-eared woolly opossum.[4]
Bushy-tailed opossum (Glironia venusta)
CaluromyinaeBlack-shouldered opossum (Caluromysiops irrupta)
Derby's woolly opossum (Caluromys derbianus)
Bare-tailed woolly opossum (Caluromys philander)
Brown-eared woolly opossum (Caluromys lanatus)
Kalinowski's mouse opossum (Hyladelphys kalinowskii)
The black-shouldered opossum is characterized by a gray coat, gray underbelly with buff-tipped hairs, and broad black stripes that extend from the forefeet, meet on the shoulders, run along the midline of the back and then split into parallel stripes that run down the hindfeet. Indistinct dark lines run through the eyes. 60 to 75 percent of the length of the tail is darker than the coat dorsally (on the back), while the rest is white. Except for the last 75 percent of the length at the base, the tail is bushy. Like Caluromys species, its fur is soft, thick and woolly, and has a similar skull. However, it differs from them in having a shorter rostrum and larger molars.[5] The head-and-body length is between 25 and 33 centimetres (9.8 and 13.0 in) and the tail measures 31–40 centimetres (12–16 in). The hindfeet measure 6.7 centimetres (2.6 in), while the ears 3.7 centimetres (1.5 in).[6]
The black-shouldered opossum's behavior is not well documented. It is nocturnal and arboreal. It spends a significant amount of time in trees, mainly on high branches. Studies suggest individual diet preferences; the opossums feed on rodents as well as fruits. Lifespan in captivity has been known to exceed seven years.[5][6] Up to two young have been recorded.[7]
The black-shouldered opossum occurs in humid forests of western Brazil and southeastern Peru, and probably in Bolivia as well. It is known only from five different localities. The IUCN classifies it as least concern given its wide distribution and presumably large population. A possible threat to its survival is deforestation.[1]
The black-shouldered opossum (Caluromysiops irrupta), also known as the white-eared opossum, is an opossum known from western Brazil and southeastern Peru. It was first described by Colin Campbell Sanborn, curator of Field Museum of Natural History, in 1951. The black-shouldered opossum is characterized by a gray coat, gray underbelly, and broad black stripes that extend from the forefeet, meet on the shoulders, run along the midline of the back and then split into parallel stripes that run down the hind feet. Little is known of the behavior of the black-shouldered opossum. It is nocturnal and arboreal. It is known to feed on fruits and rodents. The opossum inhabits humid forests. The IUCN classifies it as least concern.
