Suely Aparecida Marques-Aguiar

Non-volant mammalian diversity in fragments in extreme eastern Amazonia

Current deforestation practices are likely to result in fragmentation of much of Amazonia. Extreme eastern Amazonia (here referring to the region east of the Tocantins River) is the most populated area of the Brazilian Amazon and, unfortunately, represents the likely future scenario for remaining Amazonia. Although data are available on mammals in central Amazon fragments (the BDFFP project, http://pdbff.inpa.gov.br/), surprisingly little is known about mammalian distribution and responses to fragmentation in eastern Amazonia. As an initial step towards understanding these responses, we compiled available data on mammalian assemblage composition in four fragments east of the Tocantins River, in northeastern Pará, Brazil, between 2002 and 2006. These fragments are privately owned and embedded within a matrix of secondary forest, pasture, slash-and-burn agriculture, and roads. Survey methods included diurnal line transect censusing, nocturnal censusing, live trapping of small mammals, opportunistic observations, and interviews with local informants. Despite environmental stresses, nearly all of the expected large mammalian fauna was recorded at least once, providing reason for optimism. We documented 58 species of mammals in nine orders, and most species we failed to encounter were small nocturnal taxa for which our sampling effort likely was inadequate. Although preliminary in nature, this study highlights the need for comprehensive faunal surveys and complementary ecological research on the fauna of extreme eastern Amazonia. It also indicates that the terrestrial fauna of the region shows indications of resilience in spite of a long history of exploitation.

Cytogenetic analysis in species of the Subfamily Glossophaginae (Phyllostomidae, Chiroptera) supports a polyphyletic origin

Abstract In this work the karyotypes of 20 specimens of bats belonging to the subfamily Glossophaginae (Phyllostomidae-Chiroptera) were analyzed, species Glossophaga soricina (2n=32, FN=60), Lionycteris spurrelli (2n=28, FN=50), Lonchophylla thomasi (2n=36, FN=48) and Choeronicus minor (2n=20, FN=36), whose data were compared with each other and with data from the literature. The analyses were done using G, C, G/C sequential and NORs banding techniques and hybridization in situ with telomeric probes. Published data were also used for Artibeus lituratus (Stenodermatinae). The species G. soricina, L. spurrelli and L. thomasi presented few homeologies among themselves and none with C. minor; the latter has a pair of chromosomes shared with the species Artibeus lituratus (Stenodermatinae), indicating a possible convergent evolution in the subfamily Glossophaginae. Additionally, by comparing our results with those in the literature, interpopulational karyotypic variability was observed in the species L. thomasi.

Comparative cytogenetic analysis in the species Uroderma magnirostrum and U. bilobatum (cytotype 2n = 42) (Phyllostomidae, Stenodermatinae) in the Brazilian Amazon

The genus Uroderma includes two species: U. magnirostrum and U. bilobatum. These species are characterized by their high degree of karyotypic evolution, diverging from most other species of the subfamily Stenodermatinae, which have a lower degree of chromosomic evolution. The present study reports the first banding patterns of U. magnirostrum (G-, C-banding and Ag-NOR) and U. bilobatum (C-banding and Ag-NOR). The chromosomic data in conventional staining of U. magnirostrum (2n = 36, NF = 62) and U. bilobatum (cytotype 2n = 42, NF = 50) are equivalent to that described in the literature. When compared, chromosomal homeologies are found in both karyotypes, as well as differences, confirming that karyotypic evolution in the Uroderma genus is intense. Fission, fusion, inversion or translocation events are required to explain the karyotypic evolution of this genus. The comparison of karyotype, described here, to one of the species of the genus Artibeus (2n = 30/31), suggests that some chromosomic forms are apomorphic and shared between the two species of Uroderma. This confirms the monophyly of the genus, and that U. magnirostrum presents a more primitive karyotype when compared to U. bilobatum.

Chromosome comparison between two species of Phyllostomus (Chiroptera - Phyllostomidae) from Eastern Amazonia, with some phylogenetic insights

Os cariotipos de Phyllostomus discolor e P. hastatus da Amazonia oriental sao estudados por bandeamentos G, C, G/C sequencial e coloracao Ag-NOR. Ambas as especies apresentaram 2n = 32, sendo o complemento autossomico composto por 15 pares bi-armed em P. discolor e 14 bi-armed mais 1 par acrocentrico em P. hastatus. O cromossomo X e um submetacentrico medio e o Y e um pequeno acrocentrico em ambas as especies. O presente estudo encontrou apenas uma diferenca entre os cariotipos de P. discolor e P. hastatus: o menor autossomo (par 15) e metacentrico em discolor e acrocentrico em hastatus. Este resultado e melhor explicado por uma inversao pericentrica. O bandeamento C revelou heterocromatina constitutiva na regiao centromerica de todos os cromossomos, e os sitios NOR foram localizados na regiao distal do par 15, em ambas as especies. O taxon P. discolor e considerado primitivo para o genero Phyllostomus e supoe-se que a forma metacentrica do par 15 seja a condicao primitiva, que foi rearranjada por uma inversao pericentrica, originando a forma acrocentrica encontrada em P. hastatus.

Sex-autosome translocations: meiotic behaviour suggests an inactivation block with permanence of autosomal gene activity in Phyllostomid bats

Abstract Sex-autosome translocations are found in Chiroptera of the Phyllostomidae, leading to multiple XY1Y2 and composite neo-XY systems of chromosomal sex determination. We compared the behaviour of the sex chromosomes of Glossophaga soricina with a simple XX/XY system, Artibeus lituratus and A. obscurus with a multiple XX/XY1Y2 system, A. cinereus and Uroderma magnirostrum with a neo-XX/XY system. In this study we utilized the conventional meiosis, synaptonemic complex and C banding techniques. All the speciesform a characteristic sex vesicle in pachytene cells; whereas the diplotene cells present chiasmata points along the autosomal bivalents. In the sex chromosomes of the species with a simple system end-to-end pairing was observed for the small region of homology between X and Y, folding of the asynaptic axis of X over itself and differential condensed axes. In species with multiple and composite systems two pairing regions were visualized: the region of end-to-endpairing, as in the simple system and the pairing between the translocated autosome for the X with its homologue. Meiotic data confirm asynchronization and inactivity of the asynaptic axes of the original sex chromosomes in relation to the autosomal bivalents in the three sex chromosome systems and permanence of genic activity of the autosomes translocated to the sex chromosomes in the multiple and composite systems. This genic activity may be due to some mechanismthat blocks the diffusion of inactivation, impeding its progression to the segments of the translocated autosomes. It is probable that this occurs so as to ensure the fertility of these animals.

Comparative cytogenetics of two phyllostomids bats. A new hypothesis to the origin of the rearranged X chromosome from Artibeus lituratus (Chiroptera, Phyllostomidae)

Abstract It was carried out a cytogenetic comparison between Phyllostomus hastatus and Artibeus lituratus (Chiroptera, Phyllostomidae), using G-, C- and NOR banding techniques. The P. hastatus specimens presented 2n=32 chromosomes, including 13 biarmed autosome pairs and one acrocentric. The X chromosome is submetacentric and the Y is a minute acrocentric. A. lituratus has 2n=30 chromosomes in females and 31 in males specimens. The autosomes are 14 biarmed pairs and the chromosomal sexual system is XY1Y2 type, being the X chromosome a large submetacentric and both Y1 (real Y) and Y2 acrocentric elements. Several chromosomal homologies are shared between both taxa, including whole chromosomes and chromosomal arms. Based on similarity of G-banding pattern is proposed that the system XY1Y2 from A. lituratus risen by a tandem fusion event involving the stenodermatine original biarmed X chromosome with the autosome acrocentric homologous to Y2.

Meiotic analyses of the sex chromosomes in Carolliinae-Phyllostomidae (Chiroptera): NOR separates the XY1Y2 into two independent parts

Abstract - Meiotic analyses of the sex chromosomes were made in two different species belonging to the subfamily Carollinae (Phyllostomidae, Chiroptera): Rhinophylla pumilio and Carollia perspicillata. These species have different sex chromosome systems. Through banding techniques, chromosomes homologies between Carollia perspicillata and Rhinophylla pumilio were not found, possibly because Carollia species have highly rearranged chromosomes. Probably, Rhinophylla is better associated to Phyllostomini tribe. Sex vesicle pairing behavior at the meiotic prophase was analyzed in both species. R. pumilio had a simple sex chromosome system (XX/XY), the XY pair showed an asynchronic behavior compared to the autosomal bivalents. The sex vesicle showes the X and Y pairing in the pseudoautosomal region. Moreover, a folding of the X-asynaptic axis on itself and condensed differentiated axes were also identified. In C. perspicillata, with a multiple sex chromosome system (XY1Y2), the segments Xp-Y1 and Xq-Y2 paired independently from each other. Compared to the autosomes, the sex vesicle showed a precocious pairing behavior. In C. perspicillata, a NOR stained with silver was localized in the X rearranged chromosome. Possibly, this region separates the XY1Y2 trivalent in two independent parts: one involving the X and Y2 autosomal with transcriptional activity, and the other corresponding to the original X and Y sex pair.

Levantamento preliminar da mastofauna da região de Anajás-Muaná, Ilha de Marajó, Pará, Brasil

A short inventory of the mammalian fauna occurring in an area of the Marajo Island was performed during the rainy season. In addition to captures by using Sherman and Tomahawk traps, and mist-nets, indirect evidence was considered, e.g. finding of body fragments of specimens, vocalization, and testimonies from local people. A total of 57 species (22 families) was recorded. None of them is presently considered as critically endangered according to the IUCN criteria. First confirmed record for the fruit-eating bat Platyrrhinus brachycephalus (Rouk & Carter, 1972) in the Marajo archipelago. Additional surveys conducted in both wet and dry seasons are required for improving the profile of richness and diversity of mammal species in that region.

Comparison between the chiropteran fauna from terra firme and mangrove forests on the Bragança peninsula in Pará, Brazil

The aim of this study is to compare the density and diversity of the chiropteran fauna of the terra firme and mangrove forests of the Bragança peninsula in the Brazilian state of Pará. Bats were captured using mist nets every 2 months, resulting in the collection of 217 specimens from the terra firme and 221 from the mangrove. There was no significant difference between sites in the number of individuals or diversity. Thus, while the terra firme forest is probably the principal source of fruit, the mangrove seems to be the secondary source for opportunistic species during the period of scarcity. O objetivo deste estudo é comparar a densidade e a diversidade da fauna de quirópteros das florestas de terra firme e de manguezal da península bragantina no Estado do Pará, Brazil. Morcegos foram capturados com redes‐neblina a cada dois meses, resultando na coleta de 217 espécimes provenientes da terra firme e 221 do manguezal. Não existe diferença significativa entre os sítios de trabalho no que se refere ao número de indivíduos ou diversidade. Por isso, enquanto a floresta de terra firme é provavelmente a fonte principal de fruto, o manguezal parece ser a fonte secundária para as espécies oportunistas durante o período de escassez.

Phylogeography of the Dark Fruit-Eating Bat Artibeus obscurus in the Brazilian Amazon

Artibeus obscurus (Mammalia: Chiroptera) is endemic to South America, being found in at least 18 Brazilian states. Recent studies revealed that different populations of this genus present distinct phylogeographic patterns; however, very little is known on the population genetics structure of A. obscurus in the Amazon rainforest. Here, using a fragment (1010bp) of the mitochondrial gene cytochrome b from 87 samples, we investigated patterns of genetic divergence among populations of A. obscurus from different locations in the Brazilian Amazon rainforest and compared them with other Brazilian and South American regions. Analysis of molecular variance (AMOVA), fixation index (Fst) analysis, and phylogeographic patterns showed divergence between two major monophyletic groups, each one corresponding to a geographic region associated with the Atlantic and Amazon forest biomes. The Atlantic forest clusters formed a monophyletic group with a high bootstrap support and a fragmented distribution that follows the pattern predicted by the Refuge Theory. On the other hand, a different scenario was observed for the Amazon forest, where no fragmentation was identified. The AMOVA results revealed a significant geographic heterogeneity in the distribution of genetic variation, with 70% found within populations across the studied populations (Fst values ranging from 0.05864 to 0.09673; φST = 0.55). The intrapopulational analysis revealed that one population (Bragança) showed significant evidence of population expansion, with the formation of 2 distinct phylogroups, suggesting the occurrence of a subspecies or at least a different population in this region. These results also suggest considerable heterogeneity for A. obscurus in the Amazon region.