Monodelphis glirina, (WAGNER, 1842)

Pavan, Silvia Eliza, Rossi, Rogerio Vieira & Schneider, Horacio, 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 (1), pp. 190-223 : 202-203

MONODELPHIS GLIRINA ( WAGNER, 1842)

Type information: Holotype not cited in original description. Type locality ‘Mamoré’, Rondônia, Brazil. ‘Rio Mamoré, Cachoeira da Pau grande’ according to Pelzeln (1883), 10 ° 28′S, 65 ° 24′W ( Vanzolini, 1993). Collected by Johann Natterer. The type specimen is possibly at the Naturhistorisches Museum Wien ( NMW), where part of Natterer’s collection can be found.

Synonyms: Didelphys glirina Wagner, 1842 .

Morphological diagnosis: Same as for the M. brevicaudata complex with the following additions: HBL averages 137 mm in adult females and 153 mm in adult males (Supporting Information Table S2). Dorsal pelage with grizzled, light grey coloured stripe at mid-dorsum, differing from the light orange to orange sides ( Fig. 4 ); head pelage orange laterally and greyish dorsally, with the mid-dorsal stripe broad, occupying all crown of the head between the eyes; underparts greyish cream to greyish light-orange, not sharply differentiated from the orange sides ( Fig. 4 ); throat commonly slightly more washed with orange than the rest of the venter; mammae at the inguinal/ abdominal region, one central and eight distributed circumferentially around it ( MPEG 1318, 10134, 38985, 39115, 39140); tail covered with body fur to about the same extent above and below, up to one sixth of the caudal length. CBL averages 36.5 mm in adult females and 39.4 mm in adult males (Supporting Information Table S2); interorbital region relatively narrow ( Fig. 5 ); zygomatic arches slightly rounded anteriorly; maxillopalatine foramina relatively long ( Fig. 5 ); UMS averages 8.1 mm in adult females and 8.2 mm in adult males (Supporting Information Table S2).

Geographical distribution: South-eastern Peru, northern Bolivia and Brazil in the states of Acre, Rondônia, southern Amazonas, northern Mato Grosso, and Pará south of the Amazon river, including the eastern margin of the Xingu river ( Fig. 6 ). Monodelphis glirina occurs in sympatry with M. touan in southeastern Pará (see the Geographical distribution section of M. touan above for details).

Geographical variation: Monodelphis glirina exhibits high morphological variation, mainly in the body pelage colour. Specimens from east of the Xingu river (localities Canaã dos Carajás, Marabá, São Félix do Xingu, and São João do Araguaia, in the state of Pará) lack the mid-dorsal stripe. Instead, they exhibit upperparts greyish, with lateral orange fur restricted either to the contact line between anterior body sides and venter or to head sides. Whereas specimens of M. glirina from west of the Xingu river have greyish yellow ventral pelage, with grey-based and yellowishtipped hairs, specimens from Marabá, on the opposite side of the Xingu river, exhibit notably darker ventral fur (grey coloured). Another specimen from east of the Xingu river ( MPEG 10134, São João do Araguaia) shares with other specimens from this region the absence of a distinct stripe at mid-dorsum, but exhibits brownish orange (instead of greyish) upper fur, and greyish light-orange underparts.

Amongst specimens from west of the Xingu river, which show orange body sides, the ones from the state of Mato Grosso are generally more greyish and paler, with the grey mid-dorsal stripe appearing wider, and the orange portion on body sides proportionally lighter and narrower, restricted to the area adjacent to the venter (but not so restricted as in specimens from east of the Xingu river). In many specimens the orange fur of the body sides becomes gradually narrower toward the back, with posterior part of the body grey coloured instead of orange. The venter is yellowish, with hairs grey at the base. By contrast, specimens from Altamira, Itaituba, and Santarém, in the state of Pará, are brighter orange on the flanks, with the mid-dorsal stripe generally narrower and well delimited. The venter is more washed with orange than in specimens from Mato Grosso. Specimens from Santa Rosa, Bolivia, resemble those from Altamira, Itaituba, and Santarém with respect to dorsal and lateral pelage, but show more greyish ventral pelage. Remarks: In this study, we analysed some specimens from the eastern margin of the Xingu river labelled as M. domestica (precisely from Marabá and São Félix do Xingu). Morphological traits of their skulls revealed more similarities to M. glirina than to M. domestica . The inclusion of specimens from Marabá in our molecular analysis allowed us to confirm their allocation to M. glirina , and to extend the geographical distribution of M. glirina to the eastern bank of the Xingu river.

We concluded that the two specimens from São Félix do Xingu ( MPEG 1318 and MZUSP 9931) are the specimens cited by Carvalho (1960) as Monodelphis brevicaudata emiliae . Pine & Handley presumed M. b. emiliae from Carvalho (1960) to be their Monodelphis species ‘D’. However, our analyses have shown that M. b. emiliae as recognized by Carvalho (1960) is actually M. glirina .

Figures

Figure 4. Dorsal (left) and ventral (right) views of the skins of adult specimens of (top to bottom): Monodelphis glirina (USNM 521429), Monodelphis palliolata (USNM 406904), Monodelphis brevicaudata (USNM 385005), Monodelphis arlindoi sp. nov. (UFMG 3190, paratype), Monodelphis touan (IEPA 1154). Scale bar = 50 mm.

Figure 5. Dorsal (top) and ventral (bottom) views of the skulls of old adult specimens of: A, Monodelphis glirina (USNM 521431, female); B, Monodelphis palliolata (USNM 371285, female); C, Monodelphis brevicaudata (USNM 385005, female); D, Monodelphis arlindoi sp. nov. (MPEG 38052, holotype, male); E, Monodelphis touan (ISEM V-1563, male). Scale bar = 10 mm.

Figure 6. Distribution of species of the Monodelphis brevicaudata complex recognized in this study. Species boundaries (shades) are based on our data and Pine & Handley (2008). Points indicate collecting localities of specimens examined by us (except for species B, not analysed). Monodelphis palliolata also occurs in Colombia, but distribution in that country cannot be correctly drawn because of the absence of known precise localities (Pine & Handley, 2008).