920 resultados para SPECIES-AREA RELATIONSHIP
Resumo:
Seven new species of Lachesilla in the group forcepeta, from the Amazon Basin in Brazil, Colombia and Peru, are here described and illustrated: L. amacayacuensis sp. n. (type locality: Colombia, Amazonas, Leticia, Amacayacú); L.bulbosiforceps sp. n. (type locality: Peru, Cuzco); L. cuzcoensis sp. n. (type locality: Peru, Cuzco); L. marabaensis sp. n. (type locality: Brasil, Pará, Marabá, Serra Norte); L. pilosiforceps sp. n. (type locality: Brasil, Pará, Oriximiná, Rio Trombetas); L. pilosipenna sp. n. (type locality: Peru, Cuzco); L. squamiforceps sp. n. (type locality: Colombia, Amazonas, Leticia). The Amazon Basin is the second most rich world area for species of Lachesilla.
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A multilocus mixed-mating model was used to evaluate the mating system of a population of Couratari multiflora, an emergent tree species found in low densities (1 individual/10 ha) in lowland forests of central Amazonia. We surveyed and observed phenologically 41 trees in an area of 400 ha. From these, only four mother trees were analyzed here because few of them set fruits, which also suffered high predation. No difference was observed between the population multilocus outcrossing rate (t mp = 0.953 ± 0.040) and the average single locus rate (t sp = 0.968 ± 0.132). The four mother trees were highly outcrossed (t m ~ 1). Two out of five loci showed departures from the Hardy-Weinberg Equilibrium (HWE) expectations, and the same results occurred with the mixed-mating model. Besides the low number of trees analyzed, the proportion of loci in HWE suggests random mating in the population. However, the pollen pool was heterogeneous among families, probably due to both the small sample number and the flowering of trees at different times of the flowering season. Reproductive phenology of the population and the results presented here suggest, at least for part of the population, a long-distance pollen movement, around 1,000 m.
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Stomata are turgor-operated valves that control water loss and CO2 uptake during photosynthesis, and thereby water relation and plant biomass accumulation is closely related to stomatal functioning. The aims of this work were to document how stomata are distributed on the leaf surface and to determine if there is any significant variation in stomatal characteristics among Amazonian tree species, and finally to study the relationship between stomatal density (S D) and tree height. Thirty five trees (>17 m tall) of different species were selected. Stomatal type, density (S D), size (S S) and stomatal distribution on the leaf surface were determined using nail polish imprints taken from both leaf surfaces. Irrespective of tree species, stomata were located only on the abaxial surface (hypostomaty), with large variation in both S D and S S among species. S D ranged from 110 mm-2 in Neea altissima to 846 mm-2 in Qualea acuminata. However, in most species S D ranges between 271 and 543 mm-2, with a negative relationship between S D and S S. We also found a positive relationship between S D and tree height (r² = 0.14, p < 0.01), but no correlation was found between S D and leaf thickness. The most common stomatal type was anomocytic (37%), followed by paracytic (26%) and anisocytic (11%). We conclude that in Amazonian tree species, stomatal distribution on the leaf surface is a response most likely dependent on the genetic background of every species, rather than a reaction to environmental changes, and that somehow S D is influenced by environmental factors dependent on tree height.
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This paper aimed to evaluate the richness, abundance and frequency of sand fly occurrence in rural and urban areas American visceral Leishmaniasis -AVL is endemic in the study area of Santarém municipality, Pará state. Sand flies were collected during 1995-2000, using CDC light traps placed in neighborhoods and rural areas of the municipality. A total of 53.454 individuals and 26 species of sand flies were collected. The most abundant species in both urban and rural environments was Lutzomyia longipalpis, vector of AVL in the area. The highest species richness by capture was in rural area. In all years sampled, the largest number of species of sand fly collected was always in rural areas. The species of sand flies in urban and rural area were similar in 11 species. In the rural area other 11 species were found, a total of 22 species. Shannon-Wiener index ranged from 0.12 to 0.84 at rural areas and 0.08 to 0.34 at urban ones. In general, rural localities showed higher diversity (H') of phlebotomines than urban ones. Individual-based rarefaction curves for each area demonstrated that urban localities had the lowest expected number of phlebotomine species and the richest rural ones reach higher expected values with lower amount of individuals than urban sites. The most frequent species were Lutzomyia longipalpis, Evandromyia carmelinoi and Bichromomyia flaviscutellata.
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In this study we investigated the relationship between tambaqui fish (Colossoma macropomumi Cuvier 1818) and parasites in two fish farms (L204S and L180N) in the state of Rondônia, Brazil, during a 1-year period. The objective of the study was to describe the relationships between parasites, hosts and the environment. From the 80 fish specimens collected, 100% were parasitized by at least one parasite species. Seven ectoparasites species were recorded, six of the class Monogenea: Anacanthorus spathulatusi, Mymarothecium spp. (Mymarothecium sp. 1, Mymarothecium sp. 2 and M. viatorum), Notozothecium sp. and Linguadactyloides brinkimanni, classified as dominants, and the copepod Perulernaea gamitanae, classified as subordinate. Despite their high prevalence, the parasites were not abundant. A. spathulatus presented positive and significant correlations between the abundance of parasitism and the standard length of the hosts in the two fish farms; Mymarothecium spp. showed significant correlations, negative in L180N, and positive in L204S; significant positive correlations were observed for Notozothecium sp. in L204S, and for L.brinkimanni in L180N. Young monogeneans were found; these parasites presented a negative correlation in L180N and a significant negative correlation in L204S. The results of the correlation between the relative condition factor (Kn) and the abundance of parasites were not significant for the recorded parasite species. Regarding the hepatosomatic relation (HSR) of fish and the abundance of parasites, Anacanthorus spathulatusi showed a significant negative correlation with the HSR in L180N, and a positive correlation in L204S. Mymarothecium spp. and Notozothecium sp. presented significant positive correlations in L204S. Considering the correlation of the fish splenosomatic relation (SSR) and the abundance of parasites, L. brinkimanni presented significant correlations, positive in L180N and negative in L204S. Despite 100% prevalence, the high water quality contributes to infracommunities with low parasite abundance and good levels of Kn, HSR and SSR, allowing good tambaqui development.
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Dichaea is the largest genus of the subtribe Zygopetalinae and holds it's the highest species diversity in South America. Therefore, this study aims to describe a new species of Dichaea, which occurs in northern Brazil, Dichaea bragae Valsko, Krahl & Holanda. The new species was collected in the north of Manaus in an area of ombrophilous forest and flowered when cultivated. The epithet honors Dr. Pedro Ivo Soares Braga (in memoriam), orchidologist who conducted several studies in the Brazilian Amazon. This new species show a affinity with Dichaea tenuis C. Schweinf., however it is differentiated both vegetatively and on labellum morphology.
Resumo:
Orchidaceae is one of the largest botanical families, with approximately 780 genera. Among the genera of this family, Catasetum currently comprises 166 species. The aim of this study was to characterize the root anatomy of eight Catasetum species, verifying adaptations related to epiphytic habit and looking for features that could contribute to the vegetative identification of such species. The species studied were collected at the Portal da Amazônia region, Mato Grosso state, Brazil. The roots were fixed in FAA 50, cut freehand, and stained with astra blue/fuchsin. Illustrations were obtained with a digital camera mounted on a photomicroscope. The roots of examined species shared most of the anatomical characteristics observed in other species of the Catasetum genus, and many of them have adaptations to the epiphytic habit, such as presence of secondary thickening in the velamen cell walls, exodermis, cortex, and medulla. Some specific features were recognized as having taxonomic application, such as composition of the thickening of velamen cell walls, ornamentation of absorbent root-hair walls, presence of tilosomes, composition and thickening of the cortical cell walls, presence of mycorrhizae, endodermal cell wall thickening, the number of protoxylem poles, and composition and thickening of the central area of the vascular cylinder. These traits are important anatomical markers to separate the species within the genus and to generate a dichotomous identification key for Catasetum. Thus, providing a useful tool for taxonomists of this group
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Schefflera morototoni fruits are important food source for neotropical frugivorous birds. The objectives of the present study were to record bird species that consumed fruits of S. morototoni in a forest in the transition Cerrado-Amazon Forest, Mato Grosso, Brazil and evaluate the potential of these bird species as seed dispersers of this plant species. During 31 observation hours, from November 1 to 5, 2011, 23 bird species were recorded consuming S. morototoni fruits. Out of these, 20 bird species were considered potential seed dispersers, as they swallow the fruits whole. The species consuming the greatest number of fruits were Aburria cujubi (24% of total consumed fruits), Pteroglossus castanotis (18%), Tangara palmarum (12%), Patagioenas speciosa (11%), Ramphastos toco (8%), and Dacnis lineata (5%). The species T. palmarum showed the highest visit frequency (VF = 1.51), followed by P. castanotis (VF = 0.80), and D. lineata (VF = 0.77). All bird species employed picking foraging method for removal of fruits and in 11 species (48%) this method was the only one used. Agonistic interactions represented 13% of the total number of visits. Dacnis lineata received the highest number of attacks and P. castanotis and Pitangus sulphuratus were the more aggressive species. The high bird richness and the great number of consumed fruits indicated that the fruits of S. morototoni may be an important food resource for birds in the Cerrado-Amazon Forest transition
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Species distribution modeling has relevant implications for the studies of biodiversity, decision making about conservation and knowledge about ecological requirements of the species. The aim of this study was to evaluate if the use of forest inventories can improve the estimation of occurrence probability, identify the limits of the potential distribution and habitat preference of a group of timber tree species. The environmental predictor variables were: elevation, slope, aspect, normalized difference vegetation index (NDVI) and height above the nearest drainage (HAND). To estimate the distribution of species we used the maximum entropy method (Maxent). In comparison with a random distribution, using topographic variables and vegetation index as features, the Maxent method predicted with an average accuracy of 86% the geographical distribution of studied species. The altitude and NDVI were the most important variables. There were limitations to the interpolation of the models for non-sampled locations and that are outside of the elevation gradient associated with the occurrence data in approximately 7% of the basin area. Ceiba pentandra (samaúma), Castilla ulei (caucho) and Hura crepitans (assacu) is more likely to occur in nearby water course areas. Clarisia racemosa (guariúba), Amburana acreana (cerejeira), Aspidosperma macrocarpon (pereiro), Apuleia leiocarpa (cumaru cetim), Aspidosperma parvifolium (amarelão) and Astronium lecointei (aroeira) can also occur in upland forest and well drained soils. This modeling approach has potential for application on other tropical species still less studied, especially those that are under pressure from logging.
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An understanding of the complex ecological interaction between fig wasps and their host plants in Amazonia requires previous knowledge of their distribution and diversity. The objective of this study was to describe the composition and structure of the wasp community associated with four species of Ficus in the municipal area of Manaus, Amazonas, Brazil. A total of 600 syconia from four species were collected. The study species were: Ficus obtusifolia Kunth; Ficus citrifolia Mill; F. americana subspecies guianensis Desv. form mathewsii; and F. americana subspecies guianensis Desv. form parkeriana. Statistical analyses were used to examine the relationship between fig wasp diversity and syconium diameter, and the effect of non-pollinating wasps on numbers of pollinators and seeds. Forty three species of fig wasp were identified, distributed across seven genera (Pegoscapus, Idarnes, Aepocerus, Physothorax, Anidarnes, Heterandrium , Eurytoma). Idarnes (carme group) was the wasps genus non-pollinator with greatest number of individuals with the greatest number of infested syconia (7409 wasps in 376 syconia). Analysing non-pollinating wasp diversity in relation to fig diameter, a significant difference was observed between the four fig species. Ficus citrifolia and F. americana subspecies guianensis form mathewsii had the smallest diameter but the greatest diversity of fig wasp. Ficus obtusifolia was the only species in which the non-pollinating wasps had a significant negative effect on the number of Pegoscapus sp. and on seed production.
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The research conducted for this thesis has been carried out over a two year period as part of the Mobile Tools and Technology for customer care (MOTTO) project. The project was funded under the Applied Grant scheme administered by Enterprise Ireland and Nortel Networks Ltd. It was a partnership project between Galway-Mayo Institute of Technology, University of Limerick, National University of Ireland Galway, and a global Internet and communications company, Nortel Networks. The project aimed to investigate the enabling mobile communications technologies in e-Business and mobile communications in the area of Business-to-Business (B2B) customer care. The development of the application discussed in this thesis was developed in conjunction with the Galway-Mayo Institute of Technology, University of Limerick and AMT Ireland. The decision to develop the application in the Electronics Company of AMT in Limerick came about as a result of the contact established by Mark Southern from the University of Limerick. Mark was involved in overseeing the development and assisted in establishing the user requirements.
Resumo:
The relative population sizes of a species complex of Chauliognathus are reported, as well as their spatial distribution associated with different patches of food plants. Field work was done at Fazenda Santa Isabel, municipality of Guaíba, State of Rio Grande do Sul, Brazil. The results suggest that two mechanisms account for the reduction in food competition among the species involved: one is asynchrony in the appearance of the species in the area, and the other is aggregation in different patches of food plants. Since the species here reported show a similar colour pattern (yellow-black) the possibility of the occurrence of serial mimicry in this complex of species is dicussed.
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The specific composition and abundance variation of the ciliate community from a wastewater discharge zone in the Bahía Blanca estuary, Argentina, were studied all throughout a year, from June 1995 to May 1996. The polluted area exhibited high values of particulate organic matter and nutrients, particularly phosphates. Aloricate ciliates were represented by 15 species belonging to the genera Strombidium Claparède & Lachmann, 1859; Strombidinopsis Kent, 1881; Cyrtostrombidium Lynn & Gilron, 1993; Strobilidium Schewiakoff, 1983; Lohmmanniella Leegaard, 1915 and Tontonia Fauré-Fremiet, 1914. Tintinnids were represented by nine species belonging to the genera Tintinnidium Kent, 1881, Tintinnopsis Stein, 1867 and Codonellopsis Jörgensen, 1924. The total abundance of aloricate ciliates reached a peak of 1,800 ind. 1-1 and the total abundance of tintinnids reached a peak of 9,400 ind. 1-1. Tintinnidium balechi Barría de Cao, 1981 was the most abundant ciliate in the community. Considerations on the presence and abundance of ciliates are made in relation to physicochemical and biochemical parameters.
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The relative growth and morphological sexual maturity of Chasmagnathus granulatus Dana, 1851 are presented for the first time to a mangrove population. The crabs were obtained during low tide periods, in the mangrove of Jabaquara Beach, Paraty, Rio de Janeiro, Brazil. All crabs in intermolt stage were sexed and had their body parts measured as follows: body height (BH), carapace length (CL) and width (CW), major cheliped propodus height (PH) and length (PL) for each sex, gonopod length (GL) and abdomen width (AW) for males and females, respectively. The relative growth was described using the allometric equation y=ax b and the size at onset sexual maturity was achieved using the software Mature I. The size of specimens ranged from 4.1 mm to 39.5 mm CW. The growth pattern was different between sexes in the cheliped relationships; the relationships BH vs. CW evidenced positive allometry for juveniles; PL vs. CW and PH vs. CW positive allometry for most crabs except juvenile females; AW vs. CW and GL vs. CW evidenced positive allometry for juveniles and isometry for adults. The relationships that best indicated the change from the juvenile to the adult phase were PH vs. CW for males and AW vs. CW for females. The size in which 50% of males from this population are mature is at 19.7 mm of CW (F=144.14; p<0.05) and for females it is at 19.2 mm of CW (F=166.54; p<0.05). The sizes obtained in this mangrove population are larger than those from previous studies, that could be attributed to a species plasticity concerning the habitat structure.
Resumo:
The population of the hermit crab Pagurus criniticornis (Dana, 1852) was studied based on seasonal abundance, size frequency distribution, sex ratio, reproductive period, fecundity and shell relationship. Specimens were collected monthly by SCUBA diving in the infralittoral area of Anchieta Island, Ubatuba. A total of 1,017 individuals was analyzed. Animal size (minimum and maximum shield length, respectively) was 0.7 and 2.9 mm for males, 0.6 and 2.8 mm for non-ovigerous females, and 1.0 and 2.5 mm for ovigerous females. The sex ratio was 1:1.29. Sexual dimorphism was recorded by the presence of males in the largest size classes. Ovigerous females were captured during all months along the year, with percentages varying from 8% (July) to 84.3% (February) in relation to the total females collected. Mean ± SD fecundity was 168 ± 125 eggs and tended to increase with increasing hermit size. Shells of four gastropod species [Cerithium atratum (Born, 1778), Morula nodulosa (Adams, 1845), Anachis lyrata (Sowerby, 1832) and Modulus modulus (Linnaeus, 1758)] were occupied by ovigerous females of P. criniticornis but fecundity was not significantly different in relation to the different shell types. The profile showed continuous and intense reproduction of P. criniticornis probably related to strategies developed to compensate for interspecific competition in the studied insular area.