Seasonal home ranges and fidelity to breeding sites among ringed seals

Population structure and patterns of habitat use among ringed seals (Phoca hispida) are poorly known, in part because seasonal movements have not been adequately documented. We monitored the movements of 98 ringed seals in the Beaufort and Chukchi seas between 1990 and 2006 using three forms of telemetry. In the winter—spring period (when the seals were occupying shorefast ice), we used radio and ultra-sonic tags to track movements above and below the ice, respectively. We used satellite-linked transmitters in summer and fall (when the seals ranged away from their winter sites) to track at-sea movements. In the shorefast ice habitat, the home ranges of 27 adult males ranged from\1 to 13.9 km2 (median = 0.628) while the home ranges of 28 adult females ranged from \1 to 27.9 km2 (median = 0.652). The 3-dimensional volumes used by 9 seals tracked acoustically under the ice averaged 0.07 (SD = 0.04) km3 for subadults and adult males and 0.13 (SD = 0.04) km3 for adult females. Three of the radio-tracked seals and 9 tracked by satellite ranged up to 1,800 km from their winter/spring home ranges in summer but returned to the same small (1–2 km2) sites during the ice-bound months in the following year. The restricted movements of ringed seals during the ice-bound season— including the breeding season—limits their foraging activities for most of the year and may minimize gene flow within the species.

Contrasting patterns of genetic diversity at three different genetic markers in a marine mammal metapopulation

Many studies use genetic markers to explore population structure and variability within species. However, only a minority use more than one type of marker and, despite increasing evidence of a link between heterozygosity and individual fitness, few ask whether diversity correlates with population trajectory. To address these issues, we analyzed data from the Steller’s sea lion, Eumetiopias jubatus, where three stocks are distributed over a vast geographical range and where both genetic samples and detailed demographic data have been collected from many diverse breeding colonies. To previously published mitochondrial DNA(mtDNA) and microsatellite data sets,we have added new data for amplified fragment length polymorphism (AFLP) markers, comprising 238 loci scored in 285 sea lions sampled from 23 natal rookeries. Genotypic diversity was low relative to most vertebrates, with only 37 loci (15.5%) being polymorphic. Moreover, contrasting geographical patterns of genetic diversity were found at the three markers, with Nei’s gene diversity tending to be higher for AFLPs and microsatellites in rookeries of the western and Asian stocks, while the highest mtDNA values were found in the eastern stock. Overall, and despite strongly contrasting demographic histories, after applying phylogenetic correction we found little correlation between genetic diversity and either colony size or demography. In contrast, we were able to show a highly significant positive relationship between AFLP diversity and current population size across a range of pinniped species, even though equivalent analyses did not reveal significant trends for either microsatellites or mtDNA.

Phylogeographic analysis in populations of Protonectarina sylveirae (Saussure, 1854) (Hymenoptera, Vespidae, Polistinae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estrutura populacional e análise de variabilidade genética em rebanhos ovinos brasileiros

Pós-graduação em Ciência e Tecnologia Animal - FEIS

Comparação da dinâmica populacional e identificação dos estoques pesqueiros do camarão sete-barbas Xiphopenaeus kroyeri (Heller, 1862) (Decapoda, Penaeidae) no litoral brasileiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Biogeography of two cold-adapted genera: Psychrobacter and Exiguobacterium

The genera Exiguobacterium and Psychrobacter have been frequently detected in and isolated from polar permafrost and ice. These two genera have members that can grow at temperatures as low as -5 and -10 degrees C, respectively. We used quantitative PCR (Q-PCR) to quantify members of these genera in 54 soil or sediment samples from polar, temperate and tropical environments to determine to what extent they are selected by cold environments. These results were further analyzed by multiple linear regression to identify the most relevant environmental factors corresponding to their distribution. Exiguobacterium was detected in all three climatic zones at similar densities, but was patchier in the temperate and tropical samples. Psychrobacter was present in almost all polar samples, was at highest densities in Antarctica sediment samples, but was in very low densities and infrequently detected in temperate and tropical soils. Clone libraries, specific for the 16S rRNA gene for each genus, were constructed from a sample from each climatic region. The clone libraries were analyzed for alpha and beta diversities, as well as for variation in population structure by using analysis of molecular variance. Results confirm that both genera were found in all three climatic zones; however, Psychrobacter populations seemed to be much more diverse than Exiguobacterium in all three climatic zones. Furthermore, Psychrobacter populations from Antarctica are different from those in Michigan and Puerto Rico, which are similar to each other. The ISME Journal (2009) 3, 658-665; doi: 10.1038/ismej.2009.25; published online 26 March 2009

Recruitment and growth variation of Ophionereis reticulata (Echinodermata: Ophiuroidea)

Two growth patterns are recognized in shallow-water ophiuroids: (I) slow growth and early reproductive maturity over a long life span and (2) rapid growth with a short life span. For species with the first pattern, both growth and recruitment would reflect a reproductive pattern with long periods of resting and spawning concentrated in certain months of the year. To evaluate this hypothesis, the recruitment, population dynamics, and growth of the intertidal brittle star Ophionereis reticulata were analyzed from January 2001 to December 2002 at the Baleciro Isthmus on the southeast coast of Brazil. The species shows an annual gametogenic cycle with spawning taking place in summer. Densities varied from 0.46 to 9.46 individuals m(-2). Density variations and seawater temperature were not significantly correlated. The population structure of O. reticulata was polymodal, with at least four co-occurring cohorts. Recruitment events were recorded in March 2001, October 2001, January 2002, and September 2002. As indicated by the asymptote size (D(infinity)=11.47 mm +/- 1.46), growth constant (K=0.42 year(-1)+/- 0.12), and oscillation index (C=0.97 +/- 0.51), the growth pattern of O. reticulata seems to be based on high survivorship of juveniles and adults, where sexual maturity is reached at a small size with rapid growth in the first 2 years of life. A low level of settlement is to be expected based on these data; however, there must be a minimum successful survivorship and development for juveniles and adults. Another explanation for the lack of small individuals (disc diameter <1.0 mm) could be that recruitment is located in a different area and a post-settlement migration might be involved in the maintenance of the population.

Evidence for genetic differentiation of Octopus vulgaris (Mollusca, Cephalopoda) fishery populations from the southern coast of Brazil as revealed by microsatellites

Octopus vulgaris is a cephalopod species in several oceans and commonly caught by artisanal and industrial fisheries. In Brazil, O. vulgaris populations are mainly distributed along the southern coast and have been subjected to intensive fishing during recent years. Despite the importance of this marine resource, no genetic study has been carried out to examine genetic differences among populations along the coast of Brazil. In this study, 343 individuals collected by commercial vessels were genotyped at six microsatellite loci to investigate the genetic differences in O. vulgaris populations along the southern coast of Brazil. Genetic structure and levels of differentiation among sampling sites were estimated via a genotype assignment test and F-statistics. Our results indicate that the O. vulgaris stock consists of four genetic populations with an overall significant analogous F(ST). (phi(CT) = 0.10710, P<0.05) value. The genetic diversity was high with an observed heterozygosity of Ho = 0.987. The negative values of F(IS) found for most of the loci examined suggested a possible bottleneck process. These findings are important for further steps toward more sustainable octopus fisheries, so that this marine resource can be preserved for long-term utilization. (C) 2011 Elsevier B.V. All rights reserved.

Investigating South American biogeographic history using patterns of skull shape variation on Cerdocyon thous (Mammalia: Canidae)

Patterns of geographic variation of the canid Cerdocyon thous have historically been obscured by its remarkable intraspecific morphological variability. The observed distribution is highly associated with phytophysiognomy, a feature considered highly dynamic along geological time. In the present study, we tested whether vegetation distribution during the Holocene Glacial Maximum of South America (HGM) explains the patterns of morphological variation within Cerdocyon thous. The species was divided in groups according to paleohabitats that could support their presence during the HGM, and then tested for differences in skull morphometrics. The results obtained demonstrate that the climatic changes during the HGM influenced the population structure of this species, resulting in the establishment of geographical groups with different degrees of morphological cohesion. Higher morphological cohesion found in the Northern group might be explained by the marked discontinuity between its geographical range and the rest of the species`distribution. The Eastern and Southern morphological divergence is less striking and, although this could be related to past vegetation distribution, the disappearance of those barriers leads to a population structure that could be slowly breaking down. (C) 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 77-84.

Genetic Variability of Beauveria bassiana and a DNA Marker for Environmental Monitoring of a Highly Virulent Isolate Against Cosmopolites sordidus

The banana weevil Cosmopolites sordidus (Germar) is one of a number of pests that attack banana crops. The use of the entomopathogenic fungus Beauveria bassiana as a biological control agent for this pest may contribute towards reducing the application of chemical insecticides on banana crops. In this study, the genetic variability of a collection of Brazilian isolates of B. bassiana was evaluated. Samples were obtained from various geographic regions of Brazil, and from different hosts of the Curculionidae family. Based on the DNA fingerprints generated by RAPD and AFLP, we found that 92 and 88 % of the loci were polymorphic, respectively. The B. bassiana isolates were attributed to two genotypic clusters based on the RAPD data, and to three genotypic clusters, when analyzed with AFLP. The nucleotide sequences of nuclear ribosomal DNA intergenic spacers confirmed that all isolates are in fact B. bassiana. Analysis of molecular variance showed that variability among the isolates was not correlated with geographic origin or hosts. A RAPD-specific marker for isolate CG 1024, which is highly virulent to C. sordidus, was cloned and sequenced. Based on the sequences obtained, specific PCR primers BbasCG1024F (5'-TGC GGC TGA GGA GGA CT-3') and BbasCG1024R (5'-TGC GGC TGA GTG TAG AAC-3') were designed for detecting and monitoring this isolate in the field.

LOW GENETIC DIVERSITY IN Wolbachia-INFECTED Culex quinquefasciatus (DIPTERA: CULICIDAE) FROM BRAZIL AND ARGENTINA

Culex quinquefasciatus is a vector of human pathogens, including filarial nematodes and several viruses. Although its epidemiological relevance is known to vary across geographical regions, an understanding of its population genetic structure is still incipient. In light of this, we evaluated the genetic diversity of Cx. quinquefasciatus and Cx. pipiens x Cx. quinquefasciatus hybrids collected from nine localities in Brazil and one site in Argentina. We used mitochondrial genes cox1 and nd4, along with the coxA and wsp genes of the maternally-inherited Wolbachia endosymbiont. The nd4 fragment was invariant between samples, whilst cox1 exhibited four haplotypes that separated two types of Cx. quinquefasciatus, one clustered in southern Brazil. Low sequence diversity was generally observed, being discussed. Both Brazilian and Argentinian mosquitoes were infected with a single Wolbachia strain. As reported in previous studies with these populations, cox1 and nd4 diversity is not congruent with the population structure revealed by nuclear markers or alar morphology. Future Cx. quinquefasciatus research should, if possible, evaluate mtDNA diversity in light of other markers.

Pollen and seed flow patterns of Carapa guianensis Aublet. (Meliaceae) in two types of Amazonian forest

Various factors affect spatial genetic structure in plant populations, including adult density and primary and secondary seed dispersal mechanisms. We evaluated pollen and seed dispersal distances and spatial genetic structure of Carapa guianensis Aublet. (Meliaceae) in occasionally inundated and terra firme forest environments that differed in tree densities and secondary seed dispersal agents. We used parentage analysis to obtain contemporary gene flow estimates and assessed the spatial genetic structure of adults and juveniles. Despite the higher density of adults (diameter at breast height >= 25 cm) and spatial aggregation in occasionally inundated forest, the average pollen dispersal distance was similar in both types of forest (195 +/- 106 m in terra firme and 175 +/- 87 m in occasionally inundated plots). Higher seed flow rates (36.7% of juveniles were from outside the plot) and distances (155 +/- 84 m) were found in terra firme compared to the occasionally inundated plot (25.4% and 114 +/- 69 m). There was a weak spatial genetic structure in juveniles and in terra firme adults. These results indicate that inundation may not have had a significant role in seed dispersal in the occasionally inundated plot, probably because of the higher levels of seedling mortality.

Low polymorphism revealed in new microsatellite markers for Bemisia tabaci (Hemiptera: Aleyrodidae)

The silverleaf whitefly (Bemisia tabaci) is actually a complex of morphologically indistinct species that vary in their capacity to transmit plant viruses and to induce physiological disorders in plants of economic importance. The worldwide impact of this whitefly has increased greatly, as it is a vector of various types of phytovirus, especially geminiviruses, in plants of economic importance. The adaptability of B. tabaci to many regions of the world has fostered the appearance of various biotypes that attack a broad spectrum of host plants. We developed microsatellite markers to study genetic variability and population structure of this whitefly in Brazil. Thirteen polymorphic microsatellite markers were isolated and characterized in 20 individuals from a natural population that were collected in soybean in Campinas (SP). The number of alleles per locus ranged from one to two, and the expected heterozygosity ranged from 0.000 to 0.505. These microsatellite markers will be useful for studies and management of B. tabaci. The low polymorphism found in these molecular markers is probably associated with homology of genes expressed in these markers.

SPATIAL PATTERN OF FOUR FOREST COMMUNITIES BY RIPLEY'S K FUNCTION IN SAO PAULO STATE

Investigating tree's spatial patterns according to their size classes and according to their more abundant species can provide evidences about the structure of the vegetal community, since the spatial pattern is a key question for forestry ecology studies. The tree spatial organization patterns on the environment depend on several ecological processes and on the specific characteristics of each environment, so that the best understanding of this frame provides important elements for the knowledge on forestry formation. This paper aimed to study tree spatial patterns, according to the diameter classes and from four most abundant species in different forests, in order to provide evidences regarding to the ecology of each vegetal community. The spatial pattern description in each forestry formation was developed using Ripley's K function. The studied forestry formations were: Ombrophilous Forest, Cerradao, Seasonal Forest and Restinga Forest. In this work, a 10.24 ha plot was installed in each forestry formation, and every tree, with a circumference at breast height (CBH) larger than 15 cm were measured, georeferenced and identified. The obtained data highlights the aggregated character in tropical forests, as observed in every studied forest. The 'Cerraddo' and 'Restinga' forest trees showed close aggregate patterns. In the Ombrophilous forest, for all distance scales, the aggregate pattern was meaningful. In the seasonal forest, a random tendency was observed, although a meaningful aggregation was observed in all short distances. The spatial pattern by diameter classes was generally aggregated for trees smaller than 10 cm of diameter and between 10 and 20 cm and random for the others, proving the existence of a tendency which in young trees is more aggregated than in old ones. The spatial pattern of the dominant species is always strongly similar to the general pattern of each forestry formation. The differences between the spatial patterns of two or three coincident species, among the forestry formations, indicate that its pattern is influenced by each different environment. This stands out the importance of its self-ecology and of its ecological processes, intrinsic of each community that can explain the observed patterns.

Divide to conquer: a complex pattern of biodiversity depicted by vertebrate components in the Brazilian Atlantic Forest

The identification of northern and southern components in different vertebrate species led researchers to accept a two-component hypothesis for the Brazilian Atlantic forest (BAF). Nevertheless, neither a formal proposal nor a meta-analysis to confirm this coincidence was ever made. Our main objective here was therefore to systematically test in how many vertebrate components the BAF could be divided by analysing existing empirical data. We used two approaches: (1) mapping and comparing the proposed areas of vertebrate endemism in the BAF and (2) analysing studies mentioning spatial subdivisions in distinct forest-dependent vertebrates within the biome, by the use of panbiogeography. The four large-scale endemism area components together with the six small-scale panbiogeographical ones allowed the definition of three BAF greater regions, subdivided into nine vertebrate components, latitudinally and longitudinally organized. Empirical time estimates of the diversification events within the BAF were also reviewed. Diversification of these vertebrates occurred not only in the Pleistocene but also throughout the Miocene. Our results confirm the BAF's complex history, both in space and time. We propose that future research should be small-scale and focused in the vertebrate components identified herein. Given the BAF's heterogeneity, studying via sections will be much more useful in identifying the BAF's historical biogeography. (c) 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 107, 39-55.