The identity of two insular populations of rodents of the nominal species, Zygodontomys brevicauda (Allen & Chapman, 1893), from the Veragua Archipelago was examined. The mitochondrial cytochrome-b gene was sequenced from specimens collected on Isla Coiba (n = 10), Isla Cébaco (n = 3) and on the nearby Peninsula Azuero (n = 3) in Panama and compared with sequences of Z. brevicauda and a number of other related species from GenBank. For Panama, phylogenetic analyses identified two clades within Zygodontomys Allen, 1897; one representing Isla Coiba and another clade composed of rats from Isla Cébaco and from the mainland on the Peninsula Azuero, as well as a GenBank sequence of Z. brevicauda from Venezuela. We suggest that the population from Isla Coiba may represent a previously undescribed species of sigmodontine rodent that is endemic to this Pacific Island.

In this study, which we carried out between January 2007 and July 2008 on populations of 3 species of wild mammals in Tonosí, Los Santos province, Panama, we report the presence of larvae of Cuterebra sp. parasitizing Zygodontomys brevicauda, Liomys adspersus, and Oligoryzomys fulvescens; the prevalence values recorded in these rodent species were 1.77, 2.15, and 1.17, respectively. This is the first record of Cuterebra sp. as parasite of rodents in Panama, and L. adspersus represents a new host record.

Entre enero 2007 y julio 2008 se desarrolló una investigación en las poblaciones de roedores silvestres de la localidad de Tonosí (Los Santos, Panamá central), encontrándose larvas de Cuterebra spp. parasitando a los roedores Zygodontomys brevicauda, Liomys adspersus y Oligoryzomys fulvescens, con una prevalencia de 1.77%, 2.15% y 1.71%, respectivamente. Este es el primer reporte de Cuterebra sp., parasitando roedores en Panamá, y el primero en presentar a L. adspersus como hospedero.