910 resultados para monogamous mating
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The fly of the syrphid Microdon tigrinus is a specific social parasite of leaf-cutting ant, Acromyrmex coronatus. Six colonies of Acromyrmex coronatus were collected in plastic containers, which there was a layer of 1 cm of plaster, with the purpose of maintaining the humidity of fungus culture. Larvae of social parasite were separate for the establishment of instars number, through morphometric study. The data were measured of 165 larvae, using spiracle (length (Ls), width (Ws) and distance between spiracle (Ds)). After that, the morphometric data obtained for the larvae were submitted to cluster analysis by Wong's hybrid method, which produces the adequate number of groups through pseudo F-statistics and pseudo t-squared statistics. The three morphometric variables studied permitted grouping of larvae into the following three distinct groups: cluster 1 [long dash] consisting of 55 larvae (Ls=0.177[plus or minus]0.026, Ws=0.163[plus or minus]0.030, Ds=0.052[plus or minus]0.008 mm); cluster 2 - consisting of 20 larvae (Ls=0.631[plus or minus]0.065, Ws=0.630[plus or minus]0.049, Ds=0.065[plus or minus]0.018 mm); cluster 3 - consisting of 90 larvae (Ls=1.294[plus or minus]0.062, Ws=1.308[plus or minus]0.069, Ds=0.140[plus or minus]0.018 mm). of the all couples, only 1 obtained success in the mating, and the female, after 24 hours, began the oviposition. The female layed 76 eggs in a period of 6 days, after that, her death. The larvae emerged in the seventh day (incubation period [plus or minus] 7 days). From 76 eggs, 54 were viable, with a viability of 71.05%. This study contributes to the knowledge of Microdon tigrinus biology of, a social parasite poorly studied in Brazil.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Lemon sharks, Negaprion brevirostris, are common in the Fernando de Noronha Archipelago, but detailed information about the species in this site is lacking. The aim of this study was to describe the spatial distribution, grouping behavior, habitat use and behavioral ecology of juvenile lemon sharks in the archipelago, and their interaction with some environmental and ecological factors. During 2006 and 2007, the presence and spatial distribution of juvenile sharks were quantified through scuba diving and snorkeling at several sites of the archipelago. In 2008 the habitat use of juvenile sharks was quantified through visual census while snorkeling along 300 x 8 m strip transects. During these transects the grouping behavior of lemon sharks was quantified by ad libitum. Results indicate that Fernando de Noronha Archipelago is used as a nursery area for lemon sharks, and the parturition occurs from November to April. Juveniles preferred using shallower areas available by the tide variation and formed groups only in the presence of adult conspecifics. This preference for shallower habitats and the group behavior probably are anti-predatory tactics used by juvenile lemon sharks, in response to the low availability of shelter and high predation risk of the studied areas. Quantifications of prey availability and predation risk of juveniles showed that, in general, lemon sharks are trading-off food by security and investing in sites with higher possibility of energetic return. Behavioral observations enabled to record juvenile carangid fishes following juvenile lemon sharks, remora host-parasite and juvenile sharks foraging on schools of herrings and octopuses. We also recorded the behavior of juvenile sharks following conspecifics of similar size, circling with two or three individuals and smaller individuals giving way to larger juveniles. When adults are present, juvenile lemon sharks are more social than solitary, indicating that predation is one of the factors that contribute to social behaviors of the species. Results also suggest that when grouped the juveniles have a hierarchical organization according to body size. Furthermore, observation of large adult females with several fresh mating bites and scars in the same habitats used by juvenile lemon sharks, indicates that Fernando de Noronha Archipelago is used as nursery and mating grounds by this species
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The acoustic ecology concept involve the relation between the live organisms and their sound environment and is applied in the present work to study the context in which the humpback whale (Megaptera novaeangliae) singing behavior, known as the most complex display in the nature, occurred in the northeastern Brazilian coast, outside the core area of Abrolhos Bank, between 2005 and 2010.I analyze the singer male occurrence , their spatial distribution and probable relations with oceanographic features, such as depth, tide regimen and moon phases. I also describe the acoustic structure and temporal variation of the singing behavior, based on song frequency and time measurements outside the Abrolhos Bank, and further compare the song complexity, registered in the same period, between Abrolhos Bank (16°- 19° S, 37°- 39° W) and the adjacent North Coast, herein considered from Itacaré (14° S, 38° W) to Aracaju (11° S, 37° W). Additionally, I look for describe and analyze anthropogenic noise sources in the marine environment of the study area, produced by the oil industry as well as by the whale watching operation, relating their frequencies to the acoustic niche utilized by the humpbacks. The results indicated a great plasticity in the singing behavior, evidenced by the occurrence of singer males in diverse social structures, from solitary individuals to other groups, even containing females and calves, as well as by the diversity which compound the song, when compared between two regions inside the same breeding area, which present distinct oceanographic characteristics. The singer male distribution may be related with the continental shelf extent along the study area. The anthropogenic noise presented frequency range, amplitude and sound intensity in potential to interfere acoustically in the singing behavior of the species, may resulting in disturbance during the breeding season in the Brazilian coast. Implications about the obtained results in the humpback whale mating system are discussed. In this way, I pretend to contribute with the acoustic ecology subject and provide information to subsidize humpback whale conservation
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Men and women express different preferences for ideal romantic partners. These preferences seem to vary with the level of involvement and commitment expected for the relationship and the perceptions people have about themselves. The current work was developed to expand the findings related to this subject, investigating the market perception of romantic relationships and the effect of context on self-assessment and preferences for romantic partners. For this purpose, 753 undergraduate, Brazilian and American, were enrolled between March 2010 and November 2012 and took part in at least one of the four studies that compose this research, performing the assessment of specific stimulus-subject descriptions. Studies one and two addressed Brazilian and American samples to respectively describe female and male expectations on human mating market. It was observed that individuals from both the genders expect positive assortative mating within couples, that each trait is not evaluated independently, and, in addition to biological predispositions, factors as environmental local constrains and cultural values may also affect mating expectations. The contrasts between the samples showed that Americans valued physical-attractiveness and social-status in describing the same-gender subjects and their expected partners, while Brazilians valued social-skills. Another expectation was also identified for both genders: physically attractive women and men of high-status were expected to be paired to each other. Study three addressed males and females expectations regarding which characteristics are most relevant in ensuring desirable partnerships for same-gender individuals. The results showed that men and women can be grouped together by having similar expectations. However, the group mainly composed of men considered status characteristics as the most important attributes, while the groups mostly composed of women indicated that social skills or physical characteristics as the most important in appealing to a desirable partner. Finally, study four investigated the effect of social comparison on self-perception and mate preferences, revealing that individuals were aware of the attributes valued by the opposite-gender and that self-perception was affected by the attributes of other people. In sum, this work evidenced that romantic relationships can be interpreted as a biological market and that the value of the attributes in the romantic mating marketplace are associated with reproductive relevance of the characteristics.
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The group Callithrichidae is characterized by the flexibility in its mating system. This fact generates questions about the mechanisms that Callithrix jacchus males reach the breeding position in a group and how they prevent the subordinates reproduction, since the competition apparently happens with less intensity when compared to the females. Studies have shown the importance of social interactions and kinship among individuals in the distribution of mating opportunities in a group. This work aimed to evaluate if dyads of Callithrix jacchus males acted socially different due to kinship. We observed the agonistic and affiliative behaviours made by the males when associated in dyads (Phase 1) and when these dyads received a female (Phase 2), which was introduced in the pair`s cage for 45 minutes. In the phase 2, we also accounted for the sexual interactions between males and female in each trio. We used 16 males, 8 related (brothers-R) and 8 nonrelated (NR), as well as 8 females. Each phase lasted 4 weeks, with 3 observations/week, during 15 min/male in phase 1 and 2. In the first phase, two pairs of R males had a contested dominance and the other two, just like in the NR males, had an uncontested dominance. The NR dominant males were more aggressive than the subordinates. With the female`s entrance in the cage, all male pairs began to have an uncontested dominance. The NR males aggression frequency rose along with the subordinates` submission. In the R males, the frequency of grooming and physical contact was higher than in the NR males. So, we conclude that the low levels of agonism presented by the R males, along with the higher tolerance shown amongst them, lead us to believe that kinship attenuate the competition among these males
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Six microsatellite loci were used to quantify the mating system of two small fragmented populations (Selviria - SEL and Aparecida do Tabuado APT, Mato Grosso do Sul State) and isolated trees in pastures, of the bat-pollinated tropical tree Hymenaea stignocarpa, growing in the Center-west region of Brazil. In SEL population, seeds were collected from 11 mother-trees; in APT, from three trees and, in the case of isolated trees, from six individuals growing at least 500 m apart in pastures. To investigate if there are differences on mating system between trees in populations and isolated trees, trees from populations were pooled as a group and, likewise, the isolated trees were pooled to another group. The outcrossing rate was higher in the populations ((t) over cap (m)=0.873) than in isolated trees ((t) over cap (m)=0.857), but the difference was not significant. Significant and high differences between multi-locus and single-locus outcrossing rate were detected in populations ((t) over cap (m)-(t) over cap (s)=0.301, P<0.05) and isolated trees (<(t)over cap>(m)-(t) over cap (s) = 0.276, P < 0.05), suggesting mating between relatives. Higher paternity correlation was observed in trees from population (<(r)over cap>(p)=0.636) than in isolated trees ((r) over cap (p)=0.377), indicating the occurrence of some correlated matings and that part of offspring are full-sibs. It was not observed increased in self-fertilization rate in isolated trees in pastures. In general terms, the unique observed difference in mating system between populations and isolate trees was the high rate of correlated matings in trees from populations, due probably to the small distance among coespecifics and the pollinator behavior, visiting near trees.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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O objetivo deste trabalho foi estimar os ganhos genéticos de um teste de progênies de seringueira para a produção de borracha seca e, com base no maior tamanho efetivo populacional e maior ganho genético, obter os melhores indivíduos. Foram utilizadas 30 progênies de meios-irmãos, provenientes de sementes de polinização mista - alogamia e autogamia - de testes clonais no Estado de São Paulo. Utilizou-se o delineamento experimental de blocos ao acaso, com 30 tratamentos (progênies), 3 repetições e parcelas lineares de 10 plantas, em um espaçamento de 3x3 m, o que totalizou 900 plantas úteis. Aos três anos, o perímetro, a 50 cm do solo (PA50), e a produção de borracha seca (PBS) foram avaliadas por meio do teste precoce de produção Hamaker Morris-Mann (HMM). As variáveis foram analisadas pelo método de modelo linear misto, via procedimento REML/BLUP, em progênies com sistema reprodutivo misto e taxa de autofecundação de 22%. A identificação dos 20 melhores indivíduos quanto à PBS e ao PA50 proporcionou ganho genético de 67,96 e 16,48%, respectivamente, e um coeficiente de endogamia de aproximadamente 2,82%. O teste de progênies proporciona produção de sementes com melhor valor genético, grande variabilidade e baixa endogamia
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Bauhinia forficata, commonly known as paw-of-cow, is widely used in Brazil folk medicine for the treatment of Diabetes mellitus. The purposes of present study were to determine the repercussions of diabetes on the defense system against oxidative stress in pregnant female rats and to characterize the influence of the treatment with Bauhinia forficata extract on the antioxidant system, glycemic control, hepatic glycogen, cholesterol, triglycerides, total proteins and lipids. Virgin female Wistar rats were injected with 40 mg/kg streptozotocin (STZ) before mating. Oral administration of an aqueous extract of Bauhinia forficata leaves was given to non-diabetic and diabetic pregnant rats in 3 doses: 500 mg/kg from 0 to 4(th) day of pregnancy, 600 mg/kg from 5(th) to 14(th) day and 1000 mg/kg from 15(th) to 20(th) day. All the females were killed on the day 21 of pregnancy. A maternal blood sample was collected by venous puncture and the maternal liver was removed for biochemical measurement. The diabetic pregnant rats presented hyperglycemia, hyperlipemia, bypertriglyceridemia, hypercholesterolemia, hyperuricemia, decreased determinations of reduced glutathione (GSH) and superoxide dismutase (SOD). Treatment with B. forficata extract did not interfere in the albumin, total protein and lipid, triglyceride, cholesterol and SOD determinations. Increased hepatic glycogen, decreased uric acid concentration and increased GSH activity was observed. This last fact suggests that the plant may have some action on antioxidant defense system. However, the demonstration of the active component present in B. forficata responsible for its antioxidant effect and the increase in hepatic glycogen deserve further investigation.
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Ethnopharmacological relevance: Bauhinia forficata Link, commonly known as paw-of-cow, is widely used in Brazilian folk medicine for the treatment of diabetes.Aim of this study: To evaluate the effect of Bauhinia forficata treatment on maternal-fetal outcome and antioxidant systems of streptozotocin-induced diabetic rats.Materials and methods: Virgin female Wistar rats were injected with 40 mg/kg streptozotocin before mating. Oral administration of an aqueous extract of Bauhinia forficata leaves was given to non-diabetic and diabetic pregnant rats at increasing doses: 500 mg/kg from 0 to 4th day of pregnancy, 600 mg/kg from 5th to 14th day and 1000 mg/kg from 15th to 20th day. At day 21 of pregnancy the rats were anaesthetized with ether and a maternal blood sample was collected for the determination superoxide dismutase (SOD) and reduced glutathione (GSH). The gravid uterus was weighed with its contents and fetuses were analyzed.Results and conclusion: The data showed that the diabetic dams presented an increased glycemic level, resorption, placental weight, placental index, and fetal anomalies, and reduced GSH and SOD determinations, live fetuses, maternal weight gain, gravid uterine weight, and fetal weight. It was also verified that Bauhinia forficata treatment had no hypoglycemic effect, did not improve maternal outcomes in diabetic rats, but it contributed to maintain GSH concentration similarly to non-diabetic groups, suggesting relation with the decreased incidence of visceral anomalies. (C) 2007 Elsevier B.V. All rights reserved.