31 resultados para Anura life-history


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The effects of competition on populations of the bean weevil Zabrotes subfasciatus were analyzed during 41 generations under different competition levels. Three competition environments were established by maintaining the number of couples (6) and varying the amount of available host seeds: HC, high (limited availability of host: 1.35 g); IC, intermediate (intermediate availability of host: 6 g); and LC, low competition (abundance of host: 36 g). It was found that the distribution of the eggs laid on grains was different among treatments: in LC, for example, although females showed high fecundity (35.4 +/- 5.6 eggs/female) the number of eggs laid on each grain was small (1.2 +/- 0.4 eggs on each seed), thus avoiding larval competition of their offspring; whereas in HC treatment, females showed low fecundity (27.04 +/- 4.5 eggs/female) but laid many eggs on each grain (15.03 +/- 4.3 eggs). There were no changes in the ability to respond to different amounts of host via oviposition behavior (egg distribution) during 41 generations. However, HC females had more offspring than LC females under HC conditions. This suggests that HC insects evolved toward higher fitness in crowded conditions. In addition, after inverting the competition level, insects behaved independently of the treatment conditions they experienced through generations, thus showing that oviposition behavior is flexible. Taken together, our results show that Z. subfasciatus presents a broad range of behavioral and physiological responses which allows for quick and reversible adjustments to sudden changes in the amount of resources.

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Life-history information constitutes the raw data for building population models used in species conservation. We provide life-history data for the endangered Santa Catalina Island Rattlesnake, Crotalus catalinensis. We use data from 277 observations of C. catalinensis made between 2002 and 2011 on the island. Mean snout-vent length (SVL) of adult C. catalinensis was 643 mm for males and 631 mm for females; the difference was not significant. The degree of sexual size dimorphism (SSD; using SVL) was -0.02. However, sexes were dimorphic in total length ( SVL + tail length), relative tail length, and stoutness. Juvenile recruitment occurs during late-summer. In their first year of life, juveniles seem to grow at a rate of about 1.7 cm/mo. Females seem to become mature around 570 mm SVL, probably in the year when they become 2 y old. Scattered literature data corroborates the time of juvenile recruitment described herein. Growth in C. catalinensis seems to be slower than that of C. ruber, its sister taxa, but similar to other rattlesnakes.

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A new species of Mesabolivar is described from Brazilian forests: Mesabolivar delclaroi. The mating behaviour, postembryonic development, number of egg sacs and eggs, birth rate, number of instars, developmental time until adulthood, sex ratio and size of cephalothorax (per instar) were recorded. The sexual behaviour was described and categorized into four steps: courtship, pre-copulation, copulation and post-copulation. After hatching, individuals presented five instars until maturity. The mean number of eggs (42 +/- 16.6) and live births (31.5 +/- 3.4) of the first egg sac were significantly greater than that of a second one (23.8 +/- 3.8, and 19.25 +/- 3.9, respectively). The developmental time from birth to adulthood (130.8 +/- 9.6 days) did not differ significantly between egg sacs produced (128.61 +/- 11.1). The size of the cephalothorax did not differ among adults or between sexes. The sex ratio revealed a shift in favour of females (4: 3).

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The coconut mite, Aceria guerreronis Keifer, is one of the main pests of coconut palms (Cocos nucifera) in northeastern Brazil. The objective of this study was to evaluate the levels of the coconut mite and other mites on coconut palms in the state of So Paulo and to estimate the possible role of predatory mites in the control of this pest. The effect of cultivated genotypes and sampling dates on the mite populations was also estimated. We sampled attached fruits, leaflets, inflorescences, and fallen fruits. The coconut mite was the main phytophagous mite found on attached and fallen fruits, with average densities of 110.0 and 20.5 mites per fruit, respectively. The prevalent predatory mites on attached and fallen fruits were Proctolaelaps bulbosus Moraes, Reis & Gondim Jr. and Proctolaelaps bickleyi (Bram), both Melicharidae. On leaflets, the tenuipalpids Brevipalpus phoenicis (Geijsks) and Tenuipalpus coyacus De Leon and the tetranychid Oligonychus modestus (Banks) were the predominant phytophagous mites. On both leaflets and inflorescences, the predominant predatory mites belonged to the Phytoseiidae. Neoseiulus baraki (Athias-Henriot) and Neoseiulus paspalivorus (De Leon), predators widely associated with the coconut mite in northeastern Brazil and several other countries, were not found. The low densities of the coconut mite in So Paulo could be related to prevailing climatic conditions, scarcity of coconut plantations (hampering the dispersion of the coconut mite between fields), and to the fact that some of the genotypes cultivated in the region are unfavorable for its development.

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Brood desertion is a life history strategy that allows parents to minimize costs related to parental care and increase their future fecundity. The harvestman Neosadocus maximus is an interesting model organism to study costs and benefits of temporary brood desertion because females abandon their clutches periodically and keep adding eggs to their clutches for some weeks. In this study, we tested if temporary brood desertion (a) imposes a cost to caring females by increasing the risk of egg predation and (b) offers a benefit to caring females by increasing fecundity as a result of increased foraging opportunities. With intensive field observations followed by a model selection approach, we showed that the proportion of consumed eggs was very low during the day and it was not influenced by the frequency of brood desertion. The proportion of consumed eggs was higher at night and it was negatively related to the frequency of brood desertion. However, frequent brood desertion did not result in higher fecundity, measured both as the number of eggs added to the current clutch and the probability of laying a second clutch over the course of the reproductive season. Considering that harvestmen are sensitive to dehydration, brood desertion during the day may attenuate the physiological stress of remaining exposed on the vegetation. Moreover, since brood desertion is higher during the day, when egg predation pressure is lower, caring females could be adjusting their maternal effort to the temporal variation in predation risk, which is regarded as the main cost of brood desertion in ectotherms.

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The blattisociid mite Lasioseius floridensis Berlese was found associated with the broad mite, Polyphagotarsonemus latus (Banks), on gerbera leaves in Mogi das Cruzes, State of Sao Paulo, Brazil. Blattisociid mites are not common on aerial plant parts, except under high air humidity levels. Some Lasioseius species have been mentioned as effective control agents of rice pest mites, but nothing is known about the biology of L. floridensis. The objective of this study was to evaluate whether the observed co-occurrence of L. floridensis and P. latus was just occasional or whether the latter could be important as food source for the former, assumed by laboratory evaluation of the ability of the predator to maintain itself, reproduce and develop on that prey. Biological parameters of L. floridensis were compared when exposed to P. latus and to other items as food. The study showed that mating is a pre-requisite for L. floridensis to oviposit and that oviposition rate was much higher on the soil nematode Rhabditella axei (Cobbold) (Rhabditidae) than on P. latus. Ovipositon on the acarid mite Tyrophagus putrescentiae (Schrank) was about the same as on P. latus, but it was nearly zero when the predator was fed the fungi Aspergillus flavus Link or Penicillium sp., or cattail (Typha sp.) pollen. Survivorship was higher in the presence of pollen and lower in the presence of A. flavus or Penicillium sp. than in the absence of those types of food. Life table parameters indicated that the predator performed much better on R. axei than on P. latus. To evaluate the potential effect of L. floridensis as predator of P. latus, complementary studies are warranted to determine the frequency of migration of L. floridensis to aerial plant parts, when predation on P. latus could occur.

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The somatic and gonad productions of the cirolanid isopod Excirolana armata were analyzed by taking monthly samples from December 2003 to November 2005 on Una beach, So Paulo state (24A degrees S), southeastern Brazil. Sampling was performed along three fixed transects established from the base of the foredunes to the waterline. Weight-specific growth rate was used to estimate the E. armata somatic production for 2004 and 2005, separately. The gonad production was estimated based on the monthly reproductive potential (mean number of eggs/embryos per female x monthly abundance of ovigerous females with near-release broods) for 2004. The annual somatic production of E. armata population varied from 15.57 to 17.25 g AFDW m(-1) year(-1) and the somatic production/biomass ratio (P (s)/B) from 3.55 to 3.14 year(-1) for 2004 and 2005, respectively. The P (s)/B ratios were higher for males (4.02 and 3.19 year(-1) for 2004 and 2005) than for females (3.10 year(-1) for both years). The annual gonad production (P (g) = 1.07 g AFDW m(-1) year(-1)) contributed about 15 and 6% to the total production (P (s) + P (g)) of females and the population, respectively. The proportion of gonad to somatic production of females (P (g)/P (s)) increased with individual size (ca 90% in the 7.5 mm size class), and the annual weight-specific gonad production (P (g)/B ratio) was estimated to 0.24 year(-1). The high P (s)/B ratios estimated for E. armata derive from the fast growth of individuals and show the importance of this population to the energy flow on Una beach ecosystem. However, the low percentage of juveniles verified in this population and in other studies of populations of the genus Excirolana is discussed as an important source of underestimation of P (s)/B ratio.

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Blarinomys breviceps possesses cryptic and burrowing habits with poorly documented genetics and life history traits. Due to its rarity, only a few specimens and DNA sequences have been deposited in collections worldwide. Here, we present the most comprehensive cytogenetic and molecular characterization of this rare genus. Phylogenetic analyses based on partial cytochrome b sequences were performed, attempting to establish the relationships among individuals with distinct karyotypes along the geographic distribution of the genus in the Atlantic Forest. Classical and molecular cytogenetics, using banding patterns and FISH of telomeric and whole chromosome X-specific painting probes (obtained from the Akodontini Akodon cursor) were used to characterize and compare the chromosomal complements. Molecular phylogenetic analyses recovered 2 main geographically structured clades, northeastern and southeastern with pair-wise sequence divergences among specimens varying between 4.9 and 8.4%. Eight distinct karyomorphs are described: (A) 2n = 52 (50A, XX), (B) 2n = 52 (48A, XY+2Bs), (C) 2n = 45 (42A, XY+1B), (D) 2n = 43 (37A, XX+4Bs), (E) 2n = 37 (34A, XY+1B), (F) 2n = 34 (32A, XX), (G) 2n = 31 (27A, XX+2Bs), (H) 2n = 28 (26A, XY), all with the same number of autosomal arms (FNA = 50). Variation of 0-4 supernumerary chromosomes (Bs) presenting heterogeneity in morphology and distribution of interstitial telomeric sequences (ITSs) is reported. ITSs are also found in some metacentric autosomes. The phylogeographic separation between 2 major lineages with high levels of genetic divergence, and the wide karyotypic diversity indicate that B. breviceps is a diverse group that warrants taxonomic re-evaluation. Copyright (C) 2012 S. Karger AG, Basel

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Several predatory mites have been found in association with the coconut mite, Aceria guerreronis Keifer, in northeast Brazil. However, the latter still causes damage to coconut in that region. The objectives of this work were to compare the frequencies of occurrence of Neoseiulus (Phytoseiidae) and Proctolaelaps (Melicharidae) species on standing and aborted coconuts in coastal Pernambuco State, northeast Brazil and to analyze their possible limitations as control agents of the coconut mite, based on evaluations of the restrictions they may have to access the microhabitat inhabited by the pest and their functional and reproductive responses to increasing densities of the latter. Neoseiulus baraki (Athias-Henriot) was found mostly on standing coconuts whereas Proctolaelaps bickleyi (Bram) was found mostly on aborted coconuts. Measurements of the entrance to the microhabitat occupied by the coconut mite, between the bracts and the subjacent fruit surface, showed that this different pattern of predator prevalence could be related to predator sizes, although other environmental factors could not be disregarded. Progressively higher predation rate of N. baraki was observed up to an experimental density that corresponded to 1,200 coconut mites per fruit, which is close to the average number determined in northeast Brazil, reducing slightly afterwards. Predation rate of P. bickleyi reduced consistently but slightly with increasing prey densities, but in absolute values, rates were always much higher than determined for N. baraki. The excessively high killing capacity of P. bickleyi, probably related to its high feeding requirement, may be detrimental in terms of stability. In fact, such high requirement for food suggests that P. bickleyi might not have a strong relation with the coconut mite and that the latter may not be its main food source under natural conditions. It is concluded that body sizes of both predators and the exceedingly high feeding requirement of P. bickleyi may limit their performance as control agents of the coconut mite.

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The study of the genetic structure of wild plant populations is essential for their management and conservation. Several DNA markers have been used in such studies, as well as isozyme markers. In order to provide a better comprehension of the results obtained and a comparison between markers which will help choose tools for future studies in natural populations of Oryza glumaepatula, a predominantly autogamous species, this study used both isozymes and microsatellites to assess the genetic diversity and genetic structure of 13 populations, pointing to similarities and divergences of each marker, and evaluating the relative importance of the results for studies of population genetics and conservation. A bulk sample for each population was obtained, by sampling two to three seeds of each plant, up to a set of 50 seeds. Amplified products of eight SSR loci were electrophoresed on non-denaturing polyacrylamide gels, and the fragments were visualized using silver staining procedure. Isozyme analyses were conducted in polyacrylamide gels, under a discontinuous system, using six enzymatic loci. SSR loci showed higher mean levels of genetic diversity (A=2.83, p=0.71, A(P)=3.17, H-o=0.081, H-e=0.351) than isozyme loci (A=1.20, p=0.20, A(P)=1.38, H-o=0.006, H-e=0.056). Interpopulation genetic differentiation detected by SSR loci (R-ST=0.631, equivalent to F-ST=0.533) was lower than that obtained with isozymes (F-ST=0.772). However, both markers showed high deviation from Hardy-Weinberg expectations (F-IS=0.744 and 0.899, respectively for SSR and isozymes). The mean apparent outcrossing rate for SSR ((t) over bar (a)=0.14) was higher than that obtained using isozymes ((t) over bar (a)=0.043), although both markers detected lower levels of outcrossing in Amazonia compared to the Pantanal. The migrant number estimation was also higher for SSR (Nm=0.219) than isozymes (Nm=0.074), although a small number for both markers was expected due to the mode of reproduction of this species, defined as mixed with predominance of self fertilization. No correlation was obtained between genetic and geographic distances with SSR, but a positive correlation was found between genetic and geographic distances with isozymes. We conclude that these markers are divergent in detecting genetic diversity parameters in O. glumaepatula and that microsatellites are powerful for detecting information at the intra-population level, while isozymes are more powerful for inter-population diversity, since clustering of populations agreed with the expectations based on the geographic distribution of the populations using this marker. Rev. Biol. Trop. 60 (4): 1463-1478. Epub 2012 December 01.

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This study aimed to evaluate the importance of a descriptive narrative process of the significance involved in a depressive phenomenon. The research population consisted of 324 adult and adolescent patients of both genders, located in the central area of the city of Paraiba, for clinical and psychological health care. For surveyed patients, suffering and or psychological pain were the most common complaints. A sample of 159 patients was taken, including male and female adolescents and adults. Data were collected through a narrative interview. Shutz' procedure was used for information analysis. The obtained data offered the opportunity to review concepts, discuss life history and listen to narrative positioning episodes of manifested depression. The narratives were considered to be a determinant factor to consider inherent conflicts.

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ALBERTONI F F [Fed Univ, Florianopolis, Brazil], MORAES S S [Mus Zool USP, Sao Paulo, Brazil], STEINER J [Fed Univ. Florianopolis, Brazil] & ZILLIKENS A [Univ Tubingen, Germany]: Description of the Pupa and Redescription of the Imagines of Geyeria decussata and their Association with Bromeliads in Southern Brazil (Lepidoptera: Castniidae). - Entomol Gener 34 (1-2): 061-074: Stuttgart 2012-09. - [Article] Bromeliads can serve as a resource for numerous arthropods, especially insects. Caterpillars of the moth Geyeria decussata (Godart 1824) were recorded in the leaf rosettes of the bromeliads Wittrockia superba, Vriesea philippocoburgii and Aechmea nudicaulis. The larvae were feeding on the leaf bases, eventually killing the plants. In addition to life history data a description of the pupa and a re-description of the imagines are provided here. These findings constitute new records of larval hosts for this species and confirm a close association of castniid moths and bromeliads.

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Este trabalho teve como objetivo identificar as necessidades de saúde das pessoas com deficiência, pela ótica dos sujeitos. Realizou-se um estudo qualitativo, por meio da técnica da história de vida; foram incluídas pessoas com deficiência física, auditiva e visual, congênita e adquirida, e com atendimento no SUS. Discutiu-se: a vivência da deficiência; independência, autonomia e apoio; acesso e direitos; sentidos das intervenções; ações e estratégias. Em relação às necessidades de saúde, foram elencados onze eixos: Acesso; Apoio psicossocial; Aspectos gerais de saúde; Autonomia e independência; Dispensação de equipamentos e dispositivos de tecnologia assistiva; Informação/orientação; Prevenção/diagnóstico precoces; Reconhecimento e garantia de direitos; (Re)Encontro com atividades significativas; Validação e ajuda na construção de estratégias próprias de enfrentamento; Vínculo com profissional de saúde. Verifica-se que as necessidades identificadas pelos sujeitos incluem aspectos específicos da assistência em saúde, mas englobam outras dimensões, indicando a importância de ações integrais e intersetoriais.

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The state of the art of the studies on the production of Brazilian sandy beach macrofauna was analyzed on the basis of the data available in the literature. For this purpose, the representativeness of the production dataset was examined by latitudinal distribution, degree of exposure and morphodynamic state of beaches, taxonomic groups, and methods employed. A descriptive analysis was, further, made to investigate the trends in production of the more representative taxonomic groups and species of sandy beach macrofauna. A total of 69 macrofauna annual production estimates were obtained for 38 populations from 25 studies carried out between 22º56'S and 32º20'S. Production estimates were restricted to populations on beaches located on the southern and southeastern Brazilian coast. Most of the populations in the dataset inhabit exposed dissipative sandy beaches and are mainly represented by mollusks and crustaceans, with a smaller number of polychaetes. The trends in production among taxonomic groups follow a similar pattern to that observed on beaches throughout the world, with high values for bivalves and decapods. The high turnover rate (P/B ratio) of the latter was due to the presence of several populations of the mole crab Emerita brasiliensis, which can attain high values of productivity, in the dataset. Most of the studies focus on the comparison of production and, especially, of P/B ratio according to life history traits in populations of the same species/taxonomic group. Despite the importance of life history-production studies, other approaches, such as the effect of man-induce disturbances on the macrofauna, should be undertaken in these threatened environments.

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The timing of larval release may greatly affect the survivorship and distribution of pelagic stages and reveal important aspects of life history tactics in marine invertebrates. Endogenous rhythms of breeding individuals and populations are valuable indicators of selected strategies because they are free of the neutral effect of stochastic environmental variation. The high-shore intertidal barnacle Chthamalus bisinuatus exhibits endogenous tidal and tidal amplitude rhythms in a way that larval release would more likely occur during fortnightly neap periods at high tide. Such timing would minimize larval loss due to stranding and promote larval retention close to shore. This fully explains temporal patterns in populations facing the open sea and inhabiting eutrophic areas. However, rhythmic activity breaks down to an irregular pattern in a population within the São Sebastião Channel subjected to large variation of food supply around a mesotrophic average. Peaks of chl a concentration precede release events by 6 d, suggesting resource limitation for egg production within the channel. Also, extreme daily temperatures imposing mortality risk correlate to release rate just 1 d ahead, suggesting a terminal reproductive strategy. Oceanographic conditions apparently dictate whether barnacles follow a rhythmic trend of larval release supported by endogenous timing or, alternatively, respond to the stochastic variation of key environmental factors, resulting in an erratic temporal pattern.