Monodelphis (Mygalodelphys) peruviana (Osgood, 1913)

Voss, Robert S., Fleck, David W. & Jansa, Sharon A., 2019, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 3: Marsupials (Didelphimorphia), Bulletin of the American Museum of Natural History 2019 (432), pp. 1-89 : 36-38

Monodelphis (Mygalodelphys) peruviana

( Osgood, 1913)

VOUCHER MATERIAL (TOTAL = 4): Nuevo San Juan (AMNH 272695, 272781; MUSM 13297, 15318).

OTHER INTERFLUVIAL RECORDS: None.

IDENTIFICATION: This taxon was long treated as a synonym or subspecies of Monodelphis adusta ( Thomas, 1897) —for example, by Cabrera (1958), Gardner (2005), and Pine and Handley (2008) —but it was recognized as a valid species by Solari (2007), largely on the basis of mtDNA sequence analyses. In fact, phylogenetic analyses of multiple genes provide compelling evidence that M. adusta and M. peruviana are not sister taxa: whereas M. peruviana belongs to a robustly supported clade that includes M. handleyi , M. osgoodi Doutt, 1938 , and M. saci Pavan et al., 2017 , the sister taxon of M. adusta (as currently recognized; see below) is M. reigi Lew and Pérez-Hernández, 2004 ( Pavan et al., 2014, 2017). In light of those results, it seems reasonable to treat M. adusta and M. peruviana as distinct species, but the absence of unambiguously diagnostic morphological characters ( Solari, 2004) is a relevant problem. In effect, M. adusta and M. peruviana are names applied to haplogroups vouchered by morphologically similar material collected north and south of the Amazon, respectively. Although the application of peruviana to material from the Yavarí-Ucayali interfluve seems adequately justified by proximity to the type locality (Moyobamba, only about 200 km west of our region; Osgood, 1913), the application of adusta to the haplogroup that occurs on the north bank of the Amazon is more problematic. 8 Nevertheless, we maintain

8 The type locality of Monodelphis adusta is in the valley of the Río Magdalena (“W[est]. Cundinamarca, in the low-lying hot regions” [ Thomas, 1897: 220]), so this name properly belongs to trans-Andean populations, from which sequence data are currently unavailable.

current conventions for applying these epithets to small specimens of Mygalodelphys from western Amazonia.

To assess the problem of species diagnosis, we compared our voucher material and other referred specimens of Monodelphis peruviana with cis- Andean specimens of M. “ adusta ,” including several from the Reserva Nacional Allpahuayo-Mishana (RNAP), a north-bank locality adjacent to our region (fig. 1). Sequence data from one of our vouchers (AMNH 272695 [= RSV 2086]) and from specimens collected at RNAP (TTU 101019 [= TK 73496], TTU 101164 [= TK 73868]) document their membership in the haplogroups currently associated with these binomina (e.g., by Solari, 2007; Pavan et al., 2014). Contra Solari (2004: 150), we found no external morphological differences between these taxa: whereas he reported that adusta has shorter dorsal fur than peruviana , our measurements indicate that both species have dorsal fur that ranges from 3 to 4 mm long, and we were unable to distinguish the “ill-defined blackish area on the posterior dorsum and the rump” that was said to be present in adusta , but absent in peruviana . Likewise, we observed no consistent qualitative craniodental differences between specimens collected on opposite banks of the Amazon. Sample sizes are too small for confident statistical comparisons of craniodental measurements, but broadly overlapping ranges for most dimensions (table 12) suggest that morphometric differences, if any, are unlikely to provide a secure basis for species separation. Although we are currently unable to provide diagnoses of the taxa currently associated with these names, it seems prudent to maintain current usage pending a comprehensive revision of the subgenus Mygalodelphys .

ETHNOBIOLOGY: The Matses do not distinguish this species from other short-tailed opossums (all known as yama; see the account for Monodelphis , above) and therefore have no particular beliefs about it.

MATSES NATURAL HISTORY: The Matses have no definite knowledge of this species.

REMARKS: One of our four vouchers (AMNH 272695) was trapped on the ground in well-

TABLE 11

drained (hill-slope) primary forest; another (AMNH 272781) was trapped under a log in what was said to be primary forest by the Matses boy who caught it; a third (MUSM 13297) was trapped by another Matses child at an undisclosed location near the village; and the fourth (MUSM 15318) was caught by hand by a Matses man at the edge of his swidden.

OTHER SPECIMENS EXAMINED (TOTAL = 9): Peru — Cuzco, Camisea (USNM 582782), 2 km SW Tangoshiari (USNM 588019); Huánuco, Hacienda Exito (FMNH 23772), Hacienda San Antonio (FMNH 23774, 23775; USNM 259433); Madre de Dios, Reserva Cuzco Amazónico (MUSM 7157); San Martín, Moyobamba (FMNH 19361, 19362 [holotype]).

SPECIMENS OF MONODELPHIS ADUSTA EXAM- INED (TOTAL = 9): Ecuador — Pastaza, Mera

TABLE 12

(AMNH 67274); Sucumbíos, km 61 on Lago Agrio-Quito highway (USNM 534286); Tungurahua, Palmira (AMNH 67275); Zamora-Chinchipe, Zamora (AMNH 47189). Peru — Loreto, 25 km S Iquitos (TTU 98686, 98923, 101019, 101164).