Mammalian community structure in lowland, tropical Peru, as determined by removal trapping

Amazonian lowland rain forests are complex three-dimensional formations consisting of a variety of arboreal and terrestrial habitats. The small mammal faunas, particularly of arboreal habitats, are poorly studied, and field research generally has been limited to a few faunal inventories. We sampled the terrestrial and arboreal small mammal fauna in two floodplain forest study zones at Reserva Cuzco Amazonico, southeastern Peru, by removal trapping for 12 consecutive days in dry (June-July 1989) and rainy seasons (January-February 1990). Nineteen taxa of marsupials and rodents were captured. Small mammals were more abundant in the rainy season than in the dry season, but the relative proportions of the 11 most abundant species remained stable between seasons and study zones. Most species showed no decline in capture rates through the 12-day period, indicating that either population densities were high or animals were quite mobile. The small mammal fauna exhibited strong vertical stratification; among the 11 most abundant species, four exhibited strong biases toward terrestrial and five toward above-ground captures. The distinct arboreal small mammal community is grossly underrepresented if traps are placed only at ground level.     

Restriction Endonuclease Analysis of Mitochondrial DNA as an Aid in the Taxonomy of Naegleria and Vahlkampfia1

ABSTRACT Using restriction enzyme analysis, mitochondrial DNA fragment patterns from seven strains of pathogenic and nonpathogenic Naegleria and one strain of Vahlkampfia were compared to estimate nucleotide sequence divergence. Significantly high levels of estimated genetic variation between strains of N. gruberi, N. fowleri, and N. jadini support the current taxonomic level of the individual Naegleria species and suggest a distinct phylogeny for each group. Naegleria lovaniensis, strain TS, was shown to have significant nucleotide sequence homology with N. gruberi, strain EGs, suggesting that the two groups share a close taxonomic relationship. The pathogenic strain MB-41 of N. fowleri exhibited distinct genetic divergence from the highly homologous, pathogenic strain Nf66 and the drug-cured strain 6088. Morphologically distinct strains EGs and 1518/la of N. gruberi exhibited significantly large sequence divergence consistent with a more distant taxonomic relationship. Amoebae from the genus Vahlkampfia expressed genetic similarity with strains of N. gruberi.