Monodelphis emiliae (Thomas, 1912)

PATTON, JAMES L., DA SILVA, MARIA NAZARETH F. & MALCOLM, JAY R., 2000, Mammals Of The Rio Juruá And The Evolutionary And Ecological Diversification Of Amazonia, Bulletin of the American Museum of Natural History 2000 (244), pp. 1-306 : 77-78

Monodelphis emiliae (Thomas, 1912)

TYPE LOCALITY: ‘‘Boim, west bank Rio Tapajós, 24°9'S, 55°10'W,’’ Estado do Para´, Brazil.

DESCRIPTION: This is a small­bodied, terrestrial species with a short tail (<50 mm in length, on average) and small feet without an opposable pollex. The body is a rich redbrown in general color with a grizzled gray neck and a rose­colored venter with overtones of purple. The distinct coloration and pattern is unique among species of this genus. Selected external and cranial measure­ ments for six adult individuals is given in table 15.

COMPARISONS: This species has previously been considered a subspecies of Monodelphis brevicaudata (Erxleben) . Handley and Pine (1984) reviewed the available material and showed that M. emiliae and M. brevicaudata are, in fact, sympatric at two localities near the Rio Tapajós. These authors give details as to the differences between the two species

DISTRIBUTION AND HABITAT: This species was previously known from only 13 specimens. Most of these are from localities along the Rio Amazonas: one from the Iquitos area of northeastern Perú and 11 from scattered localities in central and eastern Brazil, from Lago Tapayuna south of Manaus (Patterson 1992) to Belém (Handley and Pine, 1984) Anderson (1997) records one specimen from Centro Dieciocho, Pando, Bolivia. To this list we add six specimens taken from four localities in the central and upper Rio Jurua´, records which extend the range of the species some 900 km southwest of the Amazon river The species was collected only on the ground in terra firme forest, typically in Sherman traps placed along fallen logs where the un­

derstory was moderately dense. Our impression is that animals were caught ‘‘by accident,’’ perhaps entering traps in search of insects attracted to our bait. Pitfall trapping with fencing (e.g., Voss and Emmons, 1996) would probably be a better method to obtain a more accurate picture of the abundance and distribution of this, and other, species of Monodelphis .

REPRODUCTION: One female with three attached young was collected in February, and parous females were taken in both February and September. All individuals with fully erupted molars of both sexes were either reproductively active or postreproductive; one female with M4 not in place was apparently nulliparous.

KARYOTYPE: 2n = 18, FN = 30, specimens karyotyped MNFS 524, 1195, 1412, JLP 15686. The autosomal complement is comprised of two pairs of large metacentric, five pairs of medium­sized to medium­small subtelocentrics, and one pair of medium­sized acrocentric elements. The X­chromosome is a small submetacentric and the Y is a small acrocentric chromosome. The karyotype appears identical to that published for several other species in the genus (Reig et al., 1977; Palma and Yates, 1996).

SPECIMENS EXAMINED (n = 6): (1) 3f — MNFS 1150, 1195, 1412; (3) 1m — MNFS 1426; (6) 1f — JLP 15686; (7) 1m — MNFS 524.

PHILANDER TIEDEMANN, 1808