Marmosa andersoni (Pine, 1972)

Astúa, D., 2015, Didelphidae, Handbook of the Mammals of the World – Volume 5 Monotremes and Marsupials, Barcelona: Lynx Edicions, pp. 129-186 : 141

18.

Anderson’s Mouse Opossum

Marmosa andersoni

French: Opossum dAnderson / German: Andersons Zwergbeutelratte / Spanish: Marmosa de Anderson

Other common names: Heavy-browed Mouse Opossum

Taxonomy. Marmosa (Stegomarmosa) andersoni Pine, 1972 ,

“Hda. [= Hacienda] Villa Carmen , Cosnipata , Cuzco, Peru.”

This species is monotypic.

Distribution. S Peru (Cusco).

Descriptive notes. Head-body 12-4— 12:5 cm, tail 17.5-19.3 cm; weight 28-38 g. Dorsal fur of Anderson’s Mouse Opossum is warm reddish-brown; hairs are brownish at their tips. Black eyes are surrounded by prominent black eye-rings that are widest anterior to eyes but do not extend to tip of muzzle. Mid-rostral fur is pale yellowishbrown; there is no mid-rostral stripe. Cheeks and throat are cream-colored. Tail length is ¢.150% of head-body length, and tail has fur on only first 20 mm of its length. Naked rest oftail is bicolored, darker dorsally than ventrally. Ventral fur is yellowishbrown to creamy, entirely with gray-based hair. Fur of mammary region is short, white, and woolly. Otherwise, fur of Anderson’s Mouse Opossum is relatively long and lax. Ears are translucent and gray-brown, appearing naked but sprinkled externally with small shiny brown hairs visible under magnification. Sexual dimorphism is evident; the male holotype possesses a lateral carpal tubercle, lacking in females. Throat gland is apparent in adults of both sexes. Females lack a pouch and have nine mammae, four on each side and an additional medial mamma. Karyotype of Anderson’s Mouse Opossum is unknown.

Habitat. [Lowland tropical rainforest (all three known locations). Six new specimens of Anderson’s Mouse Opossum collected recently were obtained in undisturbed, primary terra firma forest habitat, characterized by a relatively low abundance of large trees but with canopy higher than 30 m. Fourof these specimens were collected from a bamboo thicket, one was caught inside a bamboo ( Guadua ) cane, and one was caught in a trap set on a tree near the forest edge.

Food and Feeding. There is no information available for this species.

Breeding. One of the seven known specimens of Anderson’s Mouse Opossum was a female carrying five attached young (measuring 11 mm from crown to rump), collected in August. Juveniles belonging to age class two were collected in November.

Activity patterns. There is no information available for this species.

Movements, Home range and Social organization. All fourjuveniles collected recently were found climbing around in a single bamboo thicket, probably close to their nest. None of the recently collected specimens was observed or caught more than 3 m above the ground.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. Very little is known about extent of occurrence, ecological habits and requirements, or population sizes and trends of Anderson’s Mouse Opossum, because only seven specimens from very close locations are known. There are no apparent major threats. In the one western locality in the Camisea region, natural gasis being extracted, butit is localized. Within the projected distribution of Anderson’s Mouse Opossum, there is not a high rate of deforestation. In the vicinity of the eastern locality, there are threats, including expanding coca cultivation. Anderson’s Mouse Opossum has not been recorded from a protected area, but Manu National Park and Biosphere Reserve is located between known capture records.

Bibliography. Creighton & Gardner (2007b), Emmons & Feer (1997), Gardner (2005), Lunde & Schutt (1999), Pine (1972), Solari & Pine (2008), Voss & Jansa (2009), Voss et al. (2014).

Figures

65. Pygmy Opossum (Chacodelphys formosa), 66. Agricola’s Opossum (Cryptonanus agricola), 67. Chacoan Mouse Opossum (Cryptonanus chacoensis), 68. Guaiba Mouse Opossum (Cryptonanus guahybae), 69. Unduavi Mouse Opossum (Cryptonanus unduaviensis), 70. . Emilie’s. 9 Opossum.. Gracilinanus. (null), 71. Aceramarca Opossum (Gracilinanus aceramarcae), 72. Agile Opossum (Gracilinanus agilis), 73. Wood Sprite Opossum (Gracilinanus dryas), 74. Northern Gracile Opossum (Gracilinanus marica), 75. Brazilian Gracile Opossum (Gracilinanus microtarsus)

Distribution. S Peru (Cusco).