271 resultados para Eggs and nests


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We studied the signaling, territorial, and courtship behaviors of the diurnal frog Hylodes asper. Visual and acoustic communication were used during intraspecific interactions involving males, females. and subadults. Hylodes aspcr has a complex visual communication system, of which foot-flagging is the most distinctive display observed in the repertoire of visual signals. The splash zone produced by the waterfalls and torrents creates a high, nearly constant, humidity near the streams, reducing the risk of desiccation which enables the diurnal activity of H. asper. Although the ambient sound pressure levels (SPL), measured at the calling sites, are similar to the SPL of the advertisement calls, the high-pitched calls of H, asper, are spectrally different from the noise produced by the water current. Thus. The ambient noise produced by the water current may not interfere significantly with the acoustic communication of this species. The noise and the nearly constant and high humidity produced by the torrents and waterfalls, along with the availability of Light, probably favored the evolution of contrasting colors and visual communication in H. asper: Males of H, aspcr excavate underwater chambers that are probably used to shelter the eggs and to prevent the clutch from being drifted downstream.

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The objective of this work was to evaluated the infestion of the whitefly Bemisia tabaci (Genn.) B biotype and thrips Caliothrips phaseoli (Hood) in fifteen beans genotypes in field condition. The genotypes IAPAR 31, Rosinha G2, Jalo precoce, Perola, IAC Harmonia, Gen 99TGR110, Gen 99TG2868, Gen 99TGR3416, Gen 99TG3450, Gen 99TG823, Gen 99TGR609, IAC Jaragua, Gen 95A10061531, Gen 99TGR3114 e Gen 96A1473153V2 was used. The experiment was conducted from May to July 2006. The statistical design was randomized blocks, totalizing 15 treatments and four replications. Evaluation was realized weekly, totalizing seven samplings. The evaluations were accomplished on a weekly basis by counting B. tabaci biotype B eggs and nymphs and nymphs of C. phaseoli in 10 leaflets per plot. The less oviposition genotypes by B. tabaci biotype B were IAC Harmonia, Perola, Gen TG3114 e Gen 95A10061531, while the most oviposited were IAC Jaragua and Gen 99TG3450. The less presence of nymphs of whitefly were observed on Perola and IAC Harmonia and the most at IAC Jaragua. It was observed a negative and non significant linear correlation between average temperature versus number of silverleaf whitefly and temperature versus number of thrips was verified.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Naive experimental groups of dogs, hamsters and guinea pigs were inoculated three times subcutaneously with unfed adult extract of the tick Rhipicephalus sanguineus and challenged with adult R. sanguineus to evaluate resistance. The acquisition of resistance was based on alterations of some reproductive and feeding performance parameters of female ticks such as female and egg mass weights, engorgement, pre-oviposition and incubation periods, larval hatchability rate and efficiency rates of female ticks in converting their food reservoir to eggs and larvae. Dogs did not develop resistance under these experimental conditions; guinea pigs and hamsters, to a lesser extent, acquired an effective immunity to ticks as demonstrated by the impairment of the reproductive and feeding performance. However, the resistance induced by inoculation of the extract in the rodents seemed not to be as efficient as that induced by successive infestations.

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The number of bacteria and yeasts occurring in the organic matter inside the nests were determined both in colonies of leaf-cutting ants reared on Eucaliptus alba (control) or Sesamum indicum (experimental). Sesame leaves induce imbalance and nests usually die. In control nests the number of bacteria in newer sponge and in older sponge were similar (3.6 x 105 and 1.4 x 105 CFU/g, respectively) whereas in waste deposit the mean reached 7.3 x 107 CFU/g. The most Probable Number (MPN/g) of yeasts were 2.7 x 104, 1.3 x 105/g and 2.2 x 104 for newer sponge, older sponge and waste deposit, respectively. Using material from older sponge for comparison, the number of bacteria and yeasts reared on sesame leaves showed significant differences. The number of bacteria was 3.3 x 107 CFU/g, a value close to that found in waste deposit of normal (control) nests, whereas the number of yeasts was 6.7 x 105/g. These changes in microbial populations due to the effect of sesame leaf uptake could be a significant factor in nest imbalance and mortality when leaf-cutting ants are consuming toxic plants.

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PCR and nested-PCR methods were used to assess the frequency of Babesia bovis and Babesia bigemina infection in Boophilus microplus engorged females and eggs and in cattle reared in an area with endemic babesiosis. Blood and the engorged female ticks were from 27 naturally infested calves and 25 crossbred cows. The frequency of both Babesia species was similar in calves and cows (P > 0.05). Babesia bovis was detected in 23 (85.2%) calves and in 25 (100%) cows and B. bigemina was detected in 25 (92.6%) calves and in 21 (84%) cows. Mixed infections with the both Babesia species were identified in 42 animals, 21 in each age category. Of female ticks engorged on calves, 34.9% were negative and single species infection with B. bigemina (56.2%) was significantly more frequent (P < 0.01) than with B. bovis (4.7%). Most of the females (60.8%) engorged on cows did not show Babesia spp. infection and the frequency of single B. bovis infection (17.6%) was similar (P > 0.05) to the frequency of single B. bigemina infection (15.9%). Mixed Babesia infection was lower (P < 0.01) than single species infection in female ticks engorged either in cows (5.7%) or in calves (4.3%). An egg sample from each female was analysed for the presence of Babesia species. Of the egg samples from female ticks infected with B. bovis, 26 (47.3%) were infected while from those from female ticks infected with B. bigemina 141 (76.6%) were infected (P < 0.01). The results showed that although the frequency of both species of Babesia was similar in calves and cows, the infectivity of B. bigemina was higher to ticks fed on calves while to those ticks fed on cows the infectivity of both Babesia species was similar. © 2004 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

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A stressful environment induces cortisol that might affect fish breeding and reproduction. In the present work, which aimed to mimic aquacultural conditions of the jundia (Rhamdia quelen) hatcheries in southern South America, females were submitted to normal or stressful handling and the effects of cortisol on serum levels of 17β-estradiol (E2) and testosterone (T) were determined. In addition, the effect of stress on reproductive parameters such as eggs and swim-up fry production was also measured. Eight females from a group submitted to stressful handling (SH) conditions and eight females from a group with normal handling (NH) conditions were captured for blood sampling at D 0 and at D 1, 10, 20, 30, and 40 of the experiment. A typical cortisol response was observed in the SH females group in that they presented higher cortisol level in contrast to the NH female group, in all days sampled, except at D 0. In the 10th and 20th d, the E2 levels were lower in SH females, but cortisol levels were higher, suggesting an effect of cortisol on E2 production and/or release. Stressful handling appeared to affect both the number and the quality of the gametes because a lower number of oocytes was stripped from SH females, and from SH fertilized eggs, a lower number of viable swim-up fry was obtained to be transferred to earthen larviculture ponds. Taken together, the results indicated that stressful handling of broodstock impairs R. quelen reproduction. © Copyright by the World Aquaculture Society 2008.

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We describe the nests and nesting behaviour of six little-known birds from south-central Minas Gerais, Brazil: Red-and-white Crake Laterallus leucopyrrhus (closed/ovoid/base nest with shells of white eggs), White-throated Woodcreeper Xiphocolaptes albicollis (cavity/without-tunnel/simple/platform nest with two immaculate white eggs), Southern Bristle Tyrant Phylloscartes eximius (closed/globular/lateral nest), Sharp-tailed Tyrant Culicivora caudacuta (high cup/lateral nest with three cream-coloured eggs), White-rumped Monjita Xolmis velatus (low cup/base nest with two immaculate white eggs) and Hellmayr's Pipit Anthus hellmayri (low cup/base nest with three pale brown eggs spotted dark brown).

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The objective of this study was to evaluate the effects of three water and storage temperatures on the oocytes of the jundiá catfish, Rhamdia quelen. A factorial experimental design over time, with treatments completed in triplicate every 48 h, was used (5 × 3 × 3 × 3) to study the exposure of the oocytes to temperatures of 15, 25 and 35. °C and activated with water at 15, 25 and 35. °C each at 0, 45, 90, 135 and 180 minutes post-collection. Linear regression analysis for the response surface model indicated an interaction (p<0.05) between time and temperature of exposure with greater values for fertilization, hatching and normal larvae rates at the time of oocyte collection (70.2 ± 8.4% fertilized oocytes, 66.7 ± 29.4% hatched eggs and 30.3 ± 25.0% normal larvae). According to the statistical model, the water temperature that resulted in the highest fertilization rate was 25.6. °C (p<0.05). The rates of fertilization, hatching and normal larvae correlated positively (p<0.05) with one another, showing that these parameters can be used in the measurement of oocyte quality. Artificial fertilization of oocytes is recommended immediately after collection; if storage is necessary, it should be carried out at 15. °C. © 2011 Elsevier B.V.

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The fat body (FB) consists of two types of cells: throphocytes and oenocytes. Throphocytes are related to intermediary metabolism storing lipids, carbohydrates, and proteins while oenocytes play role in the lipids and lipoproteins production. The vitellogenin is the precursor of egg yolk (vitelline) and is synthesized on FB. The aim of this work was to analyze the effects of hormones acting in bee reproduction, as juvenile hormone (JH) and ecdisteroids (20 HE) on FB cells, where vitellogenin is synthesized. For the study were chose nurse workers that in Melipona quadrifasciata anthidioides present activated ovaries and produce eggs, and virgin queens whose ovaries are not yet activated, presenting only previtellogenic follicles. FB trophocytes from these classes of bees were cultivated in media containing different amounts of JH and 20-HE. The effects on trophocytes cytoplasm reserves of lipids, proteins, and activity of acid phosphatase were compared by observing preparations from cultured FB, treated and control, by transmission electron microscopy (TEM). The results showed that the hormones effects are related to the bee's caste and functional ovary stage. The role of acid phosphatase on mobilization of the trophocyte reserves was also determined. © 2012 Wiley Periodicals, Inc.

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The objective was to characterize female germ cell renewal during the annual reproductive cycle in two species of ostariophysian fish with distinct reproductive strategies: a siluriform, Pimelodus maculatus, in which oocyte development is group synchronous and the annual reproductive period is short; and a characiform, Serrasalmus maculatus, with asynchronous oocyte development and a prolonged reproductive period. These reproductive strategies result in fish determinate and indeterminate fecundity, respectively. Annual reproductive phases were determined by biometric and histologic analysis of gonads and interpreted according to new proposals for phase classification and stages of oocyte development (with special attention to germinal epithelium activity). Histologically, there were two types of oogonia in the germinal epithelium: single oogonia and those in mitotic proliferation. Oogonial proliferation and their entry into meiosis resulted in formation of cell nests (clusters of cells in the ovarian lamellae). Morphometric analysis was used to estimate germ cell renewal. Based on numbers of single oogonia in the lamellar epithelium, and nests with proliferating oogonia or early prophase oocytes throughout the annual reproductive cycle, oogonial proliferation and entrance into meiosis were more intense during the regenerating phase and developing phase, but decreased sharply (P < 0.05) during the spawning-capable phase. Oogonial proliferation gradually recovered during the regressing phase. We concluded that, independent of species or features of the reproductive cycle, germ cell renewal occurred during the regenerating phase, ensuring availability of eggs for the spawning event. © 2013 Elsevier Inc.

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Due to the few studies about grafting in net melon, in order to obtain better control of soil pathogens, the aim of the present study was to evaluate 16 genotypes of Cucurbitaceae: Benincasa hispida, Luffa cylindrica, pumpkin 'Jacarezinho', pumpkin 'Menina Brasileira', squash 'Exposição', squash 'Coroa', pumpkin 'Canhão Seca', pumpkin 'Squash', pumpkin 'Enrrugado Verde', pumpkin 'Mini Paulista', pumpkin 'Goianinha', watermelon 'Charleston Gray', melon 'Rendondo Gaucho', melon 'Redondo Amarelo', cucumber 'Caipira HS' and cucumber 'Caipira Rubi', regarding to compatibility of grafting in net melon and resistance to Meloidogyne incognita, based on the reproduction factor (RF), according to Oostenbrink (1966). To assess resistance, the seedlings were transplanted to ceramic pots and inoculated with 300/mL eggs and/or second stage juveniles of M. incognita. At 50 days after transplanting, the plants were removed from the pots and the resistance was evaluated. The compatibility between resistant rootstock and grafts of net melon was determined by performing simple cleft grafting, in a commercial net melon hybrid of great market acceptance and susceptible to M. incognita (Bonus no. 2). The genotypes Luffa cylindrica, pumpkin 'Goianinha', pumpkin 'Mini-Paulista', melon 'Redondo Amarelo', watermelon 'Charleston Gray' are resistant to the nematode M. incognita. The better compatibilities occurred with the rootstocks melon 'Amarelo', which presented 100% of success, followed by pumpkin 'Mini-Paulista' with 94%. On the other hand, Sponge gourd, watermelon 'Charleston Gray' and pumpkin 'Goianinha' showed low graft take percentages of 66%, 62% and 50%, respectively.

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Human intestinal parasites constitute a problem in most tropical countries, causing death or physical and mental disorders. Their diagnosis usually relies on the visual analysis of microscopy images, with error rates that may range from moderate to high. The problem has been addressed via computational image analysis, but only for a few species and images free of fecal impurities. In routine, fecal impurities are a real challenge for automatic image analysis. We have circumvented this problem by a method that can segment and classify, from bright field microscopy images with fecal impurities, the 15 most common species of protozoan cysts, helminth eggs, and larvae in Brazil. Our approach exploits ellipse matching and image foresting transform for image segmentation, multiple object descriptors and their optimum combination by genetic programming for object representation, and the optimum-path forest classifier for object recognition. The results indicate that our method is a promising approach toward the fully automation of the enteroparasitosis diagnosis. © 2012 IEEE.

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