Effects of parasites and predators on nociception: decreases analgesia reduces overwinter survival in root voles (Rodentia: Cricetidae)

ABSTRACT Growing evidence suggests that parasite-infected prey is more vulnerable to predation. However, the mechanism underlying this phenomenon is obscure. In small mammals, analgesia induced by environmental stressors is a fundamental component of the defensive repertoire, promoting defensive responses. Thus, the reduced analgesia may impair the defensive ability of prey and increase their predation risk. This study aimed to determine whether coccidia infection increases the vulnerability to predation in root voles, Microtus oeconomus (Pallas, 1776), by decreased analgesia. Herein, a predator stimulus and parasitic infection were simulated in the laboratory via a two-level factorial experiment, then, the vole nociceptive responses to an aversive thermal stimulus were evaluated. Further, a field experiment was performed to determine the overwinter survival of voles with different nociceptive responses via repeated live trapping. The coccidia-infected voles demonstrated reduced predator-induced analgesia following exposure to predator odor. Meanwhile, pain-sensitive voles had lower overwinter survival than pain-inhibited voles in enclosed populations throughout the duration of the experiment. Our findings suggest that coccidia infection attenuates predator-induced analgesia, resulting in an increased vulnerability to predation.

Effects of parasites and predators on nociception: decreases analgesia reduces overwinter survival in root voles (Rodentia: Cricetidae)

Growing evidence suggests that parasite-infected prey is more vulnerable to predation. However, the mechanism underlying this phenomenon is obscure. In small mammals, analgesia induced by environmental stressors is a fundamental component of the defensive repertoire, promoting defensive responses. Thus, the reduced analgesia may impair the defensive ability of prey and increase their predation risk. This study aimed to determine whether coccidia infection increases the vulnerability to predation in root voles, Microtus oeconomus (Pallas, 1776), by decreased analgesia. Herein, a predator stimulus and parasitic infection were simulated in the laboratory via a two-level factorial experiment, then, the vole nociceptive responses to an aversive thermal stimulus were evaluated. Further, a field experiment was performed to determine the overwinter survival of voles with different nociceptive responses via repeated live trapping. The coccidia-infected voles demonstrated reduced predator-induced analgesia following exposure to predator odor. Meanwhile, pain-sensitive voles had lower overwinter survival than pain-inhibited voles in enclosed populations throughout the duration of the experiment. Our findings suggest that coccidia infection attenuates predator-induced analgesia, resulting in an increased vulnerability to predation.(AU)

Effects of parasites and predators on nociception: decreases analgesia reduces overwinter survival in root voles (Rodentia: Cricetidae)

ABSTRACT Growing evidence suggests that parasite-infected prey is more vulnerable to predation. However, the mechanism underlying this phenomenon is obscure. In small mammals, analgesia induced by environmental stressors is a fundamental component of the defensive repertoire, promoting defensive responses. Thus, the reduced analgesia may impair the defensive ability of prey and increase their predation risk. This study aimed to determine whether coccidia infection increases the vulnerability to predation in root voles, Microtus oeconomus (Pallas, 1776), by decreased analgesia. Herein, a predator stimulus and parasitic infection were simulated in the laboratory via a two-level factorial experiment, then, the vole nociceptive responses to an aversive thermal stimulus were evaluated. Further, a field experiment was performed to determine the overwinter survival of voles with different nociceptive responses via repeated live trapping. The coccidia-infected voles demonstrated reduced predator-induced analgesia following exposure to predator odor. Meanwhile, pain-sensitive voles had lower overwinter survival than pain-inhibited voles in enclosed populations throughout the duration of the experiment. Our findings suggest that coccidia infection attenuates predator-induced analgesia, resulting in an increased vulnerability to predation.

Thermoregulation mode, substrate temperature and camouflage efficiency affecting defensive behavior of lizards in Amazonia / Modo de termorregulação, temperatura do substrato e eficiência da camuflagem afetam o comportamento defensivo de lagartos na Amazônia

In ectotherms, defensive responses to predators usually depend on cost-benefit relationships between death risk and the energy required to flee. In this study we investigate Amazonian lizards to test the hypothesis that the minimum predator approach distance (PAD) is influenced by temperature and camouflage. We test the hypothesis that PAD estimated for species with different thermoregulation modes respond differently to temperature and camouflage. We sampled 35 lizards of a heliotherm and a non-heliotherm species, for which we simulated a terrestrial visually oriented predator. Using a fixed-effects linear model, temperature positively affected PAD estimates, but the camouflage did not contribute to the model. Using a mixed linear model assuming thermoregulation mode as a random factor, camouflage negatively affected PAD estimates, independently of temperature. Our findings suggest that high exposure to predators in open habitats may be compensated by rapid fleeing optimized by high temperatures, and low fleeing performance, usually caused by relatively low temperatures in shaded habitats, may be compensated by camouflage. However, identifying the best PAD predictor greatly depended on accounting for thermoregulation mode in hypothesis testing, although the results obtained by both fixed and mixed-effects models may be relevant for conservation.(AU)

Em ectotérmicos, respostas defensivas a predadores geralmente dependem de relações de custo-benefício entre risco de morte e a energia necessária para fugir. Neste estudo, investigamos lagartos na Amazônia para testar a hipótese de que a distância mínima de aproximação de predadores (DAP) é influenciada pela temperatura e camuflagem. Nós testamos a hipótese de que estimativas de DAP para espécies com diferentes modos de termorregulação respondem diferentemente à temperatura e camuflagem. Nós amostramos 35 lagartos de uma espécie heliotérmica e uma não heliotérmica, para as quais simulamos um predador terrestre visualmente orientado. Usando um modelo linear de efeitos fixos, a temperatura afetou positivamente as estimativas de DAP, mas a camuflagem não contribuiu para o modelo. Usando um modelo linear de efeitos mistos, a camuflagem afetou negativamente as estimativas de DAP, independentemente de temperatura. Nossos resultados sugerem que alta exposição a predadores em hábitats abertos pode ser compensada por fuga rápida otimizada por altas temperaturas, e o baixo desempenho de fuga, usualmente causado por temperaturas relativamente mais baixas em habitats sombreados, pode ser compensado pela camuflagem. No entanto, a identificação do melhor preditor de DAP dependeu muito de considerar o modo de termorregulação nos testes de hipóteses, apesar de que os resultados obtidos por ambos os modelos de efeitos fixos e mistos podem ser relevantes para conservação.(AU)

Disruptive coloration and habitat use by seahorses

Predation avoidance is a primary factor influencing survival. Therefore, any trait that affects the risk of predation, such as camouflage, is expected to be under selection pressure. Background matching (homochromy) limits habitat use, especially if the habitat is heterogeneous. Another camouflage mechanism is disruptive coloration, which reduces the probability of detection by masking the prey's body contours. Here we evaluated if disruptive coloration in the longsnout seahorse, Hippocampus reidi, allows habitat use diversification. We analyzed 82 photographs of animals, comparing animal and background color, and registering anchorage substrate (holdfast). We tested whether the presence (disruptive coloration) or absence of bands (plain coloration) predicted occupation of backgrounds of different colors. We also calculated the connectance between seahorse morph and background color or holdfast, as well as whether color morph differed in their preferences for holdfast. Animals with disruptive coloration were more likely to be found in environments with colors different from their own. Furthermore, animals with disruptive coloration occupied more diversified habitats, but as many holdfasts as plain colored animals. Therefore, animals with disruptive coloration were less selective in habitat use than those lacking disruptive color patterns, which agrees with the disruptive coloration hypothesis.(AU)

Evitar a predação é um dos principais fatores que influenciam a sobrevivência. Portanto, qualquer traço que afete o risco de predação, como a camuflagem, deverá estar sob forte pressão de seleção. Confundir-se com a cor do fundo (homocromia) limita o uso do habitat, especialmente se ele é heterogêneo. Outro mecanismo de camuflagem é a coloração disruptiva, que reduz a probabilidade de detecção mascarando o contorno do corpo da presa. Aqui nós avaliamos se a coloração disruptiva no cavalo-marinho de focinho comprido, Hippocampus reidi, permite diversificar o uso do habitat. Analisamos 82 fotografias de animais, comparando a cor do animal à do fundo, e registrando o substrato de apoio (holdfast). Nós testamos se a presença (coloração disruptiva) ou ausência de bandas (coloração lisa) predizia a ocupação de substratos de cores diferentes. Nós também calculamos a conectância entre o morfo do cavalo-marinho e a cor do fundo ou o substrato de apoio, bem como se o morfo diferiu em suas preferências por substratos de apoio. Animais com coloração disruptiva eram mais encontrados em ambientes com cores diferentes de sua própria cor. Além disso, os animais com coloração disruptiva ocupavam habitats mais diversificados, mas tantos substratos de apoio quanto animais lisos. Portanto, animais com cores disruptivas eram menos seletivos do que animais lisos quanto ao habitat que utilizavam, o que concorda com a hipótese da coloração disruptiva.(AU)

Disruptive coloration and habitat use by seahorses

Predation avoidance is a primary factor influencing survival. Therefore, any trait that affects the risk of predation, such as camouflage, is expected to be under selection pressure. Background matching (homochromy) limits habitat use, especially if the habitat is heterogeneous. Another camouflage mechanism is disruptive coloration, which reduces the probability of detection by masking the prey's body contours. Here we evaluated if disruptive coloration in the longsnout seahorse, Hippocampus reidi, allows habitat use diversification. We analyzed 82 photographs of animals, comparing animal and background color, and registering anchorage substrate (holdfast). We tested whether the presence (disruptive coloration) or absence of bands (plain coloration) predicted occupation of backgrounds of different colors. We also calculated the connectance between seahorse morph and background color or holdfast, as well as whether color morph differed in their preferences for holdfast. Animals with disruptive coloration were more likely to be found in environments with colors different from their own. Furthermore, animals with disruptive coloration occupied more diversified habitats, but as many holdfasts as plain colored animals. Therefore, animals with disruptive coloration were less selective in habitat use than those lacking disruptive color patterns, which agrees with the disruptive coloration hypothesis.(AU)

Evitar a predação é um dos principais fatores que influenciam a sobrevivência. Portanto, qualquer traço que afete o risco de predação, como a camuflagem, deverá estar sob forte pressão de seleção. Confundir-se com a cor do fundo (homocromia) limita o uso do habitat, especialmente se ele é heterogêneo. Outro mecanismo de camuflagem é a coloração disruptiva, que reduz a probabilidade de detecção mascarando o contorno do corpo da presa. Aqui nós avaliamos se a coloração disruptiva no cavalo-marinho de focinho comprido, Hippocampus reidi, permite diversificar o uso do habitat. Analisamos 82 fotografias de animais, comparando a cor do animal à do fundo, e registrando o substrato de apoio (holdfast). Nós testamos se a presença (coloração disruptiva) ou ausência de bandas (coloração lisa) predizia a ocupação de substratos de cores diferentes. Nós também calculamos a conectância entre o morfo do cavalo-marinho e a cor do fundo ou o substrato de apoio, bem como se o morfo diferiu em suas preferências por substratos de apoio. Animais com coloração disruptiva eram mais encontrados em ambientes com cores diferentes de sua própria cor. Além disso, os animais com coloração disruptiva ocupavam habitats mais diversificados, mas tantos substratos de apoio quanto animais lisos. Portanto, animais com cores disruptivas eram menos seletivos do que animais lisos quanto ao habitat que utilizavam, o que concorda com a hipótese da coloração disruptiva.(AU)

Time allocations for different activities in the fiddler crab Tubuca rosea(Tweedie, 1937) (Brachyura, Ocypodidae)ˆien

Investigating the time activity budgets of fiddler crabs is very important to determine the effects of sex and body size on allocating time for different activities. Few previous studies investigated the effects of sex and body size on time allocations in underground mating species. This study determines the effects of sex, size and their interaction on time allocations in a surface mating species (Tubuca rosea (Tweedie, 1937)). The surface activities of large and small, male and female crabs were video recorded. Afterwards time allocations for various activities (e.g., feeding, standing (vigilance), walking, inside burrows, grooming, burrowing, mating, and for males only, fighting and claw-waving) were calculated. All crabs spent most of their time on feeding than on other activities. Smaller crabs spent more time being vigilant, whereas larger crabs spent more time on courtship displays (grooming, and waving), and fighting. Between sexes, females spent more time standing, but less time on walking and grooming than males. Predation risk, reproductive maturation, breeding/non-breeding season, and energy conservation could be important factors for shaping time allocations in T. rosea.(AU)

Time allocations for different activities in the fiddler crab Tubuca rosea(Tweedie, 1937) (Brachyura, Ocypodidae)ˆien

Investigating the time activity budgets of fiddler crabs is very important to determine the effects of sex and body size on allocating time for different activities. Few previous studies investigated the effects of sex and body size on time allocations in underground mating species. This study determines the effects of sex, size and their interaction on time allocations in a surface mating species (Tubuca rosea (Tweedie, 1937)). The surface activities of large and small, male and female crabs were video recorded. Afterwards time allocations for various activities (e.g., feeding, standing (vigilance), walking, inside burrows, grooming, burrowing, mating, and for males only, fighting and claw-waving) were calculated. All crabs spent most of their time on feeding than on other activities. Smaller crabs spent more time being vigilant, whereas larger crabs spent more time on courtship displays (grooming, and waving), and fighting. Between sexes, females spent more time standing, but less time on walking and grooming than males. Predation risk, reproductive maturation, breeding/non-breeding season, and energy conservation could be important factors for shaping time allocations in T. rosea.

Relating flight initiation distance in birds to tropical dry forest restoration

Flight initiation distance (FID), defined as the distance at which an individual flees from an approaching predator, might depend on how the individual perceives the risk of being predated. Using a standardized walking approach method on focal bird individuals, we investigated whether different levels of vegetation cover (habitat) influence the perception of predation risk. To do this, we worked in an area of tropical dry forest in central Mexico that is currently part of a restoration ecology experiment. We hypothesized that restoration decreases individuals predation risk perception by increasing the complexity of the vegetation cover. The escape responses of three tropical birds with different diets and foraging strategies were also contrasted. There was no effect of habitat on FID, suggesting that birds in both habitats perceived predation risk in a similar manner. There was, however, a difference in FID among species: the Golden-cheeked Woodpecker tolerated closer human presence before flight than the Inca Dove and Streak-backed Oriole. This difference is likely due to the use of an alternative avoidance strategy of this species, which uses trunks for hiding. To decrease birds perceived predation risk, restoration intervention plans should include a mosaic of larger excluded plots located near relatively well-conserved sites to increase the area covered by vegetation.

Relating flight initiation distance in birds to tropical dry forest restoration

Flight initiation distance (FID), defined as the distance at which an individual flees from an approaching predator, might depend on how the individual perceives the risk of being predated. Using a standardized walking approach method on focal bird individuals, we investigated whether different levels of vegetation cover (habitat) influence the perception of predation risk. To do this, we worked in an area of tropical dry forest in central Mexico that is currently part of a restoration ecology experiment. We hypothesized that restoration decreases individuals predation risk perception by increasing the complexity of the vegetation cover. The escape responses of three tropical birds with different diets and foraging strategies were also contrasted. There was no effect of habitat on FID, suggesting that birds in both habitats perceived predation risk in a similar manner. There was, however, a difference in FID among species: the Golden-cheeked Woodpecker tolerated closer human presence before flight than the Inca Dove and Streak-backed Oriole. This difference is likely due to the use of an alternative avoidance strategy of this species, which uses trunks for hiding. To decrease birds perceived predation risk, restoration intervention plans should include a mosaic of larger excluded plots located near relatively well-conserved sites to increase the area covered by vegetation.(AU)

Isolation of Salmonella spp. in cattle egrets (Bubulcus ibis) from Fernando de Noronha Archipelago, Brazil

The growth of the population of cattle egrets (Bubulcus ibis) in the archipelago of Fernando de Noronha constitutes a threat to public health and biological diversity because of their competition with and predation on native species and the possibility of transmission of pathogens to human beings, livestock and native wildlife. The aim here was to search for, isolate and identify serovars of Salmonella in clinically healthy local cattle egrets. Cloacal swabs were obtained from 456 clinically healthy cattle egrets of both sexes and a variety of ages. The swabs were divided into 51 pools. Six of these (11.7%) presented four serovars of Salmonella enterica subspecies enterica: Salmonella serovar Typhimurium; Salmonella serovar Newport; Salmonella serovar Duisburg; and Salmonella serovar Zega. One sample was identified as S. enterica subspecies enterica O16:y:-. Results in this study suggest that cattle egrets may be reservoirs of this agent on Fernando de Noronha and represent a risk to public health and biological diversity.(AU)

Optimal foraging or predator avoidance: why does the Amazon spider Hingstepeira folisecens (Araneae: Araneidae) adopt alternative foraging behaviors?

Strategies that increase foraging efficiency may also increase predation risk. We investigated how individuals of Hingstepeira folisecens Hingston, 1932, which build shelters at the orb hub, modulate their foraging behaviors in response to the trade-off between capturing prey and becoming exposed by leaving their shelters. We evaluated whether the position of the prey on the web alters the frequency at which spiders leave their shelters. Hingstepeira folisecens spiders were more likely to capture prey positioned below than above the entrance of the shelter. Moreover, when the prey was near the entrance of the shelter, the spider pulled the threads with the entangled prey without leaving the shelter. Conversely, when the prey was distant from the entrance of the shelter, an "attack" behavior (leaving the shelter) was favored. We argue that the "pulling behavior" may be an adaptation to reduce exposure to predators.

Optimal foraging or predator avoidance: why does the Amazon spider Hingstepeira folisecens (Araneae: Araneidae) adopt alternative foraging behaviors?

Strategies that increase foraging efficiency may also increase predation risk. We investigated how individuals of Hingstepeira folisecens Hingston, 1932, which build shelters at the orb hub, modulate their foraging behaviors in response to the trade-off between capturing prey and becoming exposed by leaving their shelters. We evaluated whether the position of the prey on the web alters the frequency at which spiders leave their shelters. Hingstepeira folisecens spiders were more likely to capture prey positioned below than above the entrance of the shelter. Moreover, when the prey was near the entrance of the shelter, the spider pulled the threads with the entangled prey without leaving the shelter. Conversely, when the prey was distant from the entrance of the shelter, an "attack" behavior (leaving the shelter) was favored. We argue that the "pulling behavior" may be an adaptation to reduce exposure to predators.(AU)

Factors affecting escape distance in birds

The flight initiation distance has been used either to understand the cost-benefit trade-offs related to the risk of predation or as an important tool for wildlife managers. Although this variable is well-discussed for temperate regions, it is still poorly known in the Neotropics. Here we analyze the escape behavior of birds from southeastern Brazil, comparing an urban to a non-urban area. We tested for the influence of sites (urban vs. non-urban area), approaching (by one vs. two people), daytime (morning vs. afternoon), seasons (breeding vs. non-breeding) and body mass on the determination of the initial (FID) and final (FFD) flight distances across different bird species. We predict that FID will be greater in rural areas and under a greater threat (higher number of predators approaching) in the afternoon and in the non-breeding season. We also expect a direct relationship between body mass and FID and between FID and FFD. We sampled 11 species after measuring 331 escape behaviors, and we confirmed our predictions for sites (five species), daytime (one species) and rejected our premise about seasons for one species. Mean FID was strongly affected by body mass, and directly affected FFD. Adjustments in FID are, most likely, an important adaptive trait in urban habitats and may partially explain the predominance of species with higher ecological plasticity in cities.

Factors affecting escape distance in birds

The flight initiation distance has been used either to understand the cost-benefit trade-offs related to the risk of predation or as an important tool for wildlife managers. Although this variable is well-discussed for temperate regions, it is still poorly known in the Neotropics. Here we analyze the escape behavior of birds from southeastern Brazil, comparing an urban to a non-urban area. We tested for the influence of sites (urban vs. non-urban area), approaching (by one vs. two people), daytime (morning vs. afternoon), seasons (breeding vs. non-breeding) and body mass on the determination of the initial (FID) and final (FFD) flight distances across different bird species. We predict that FID will be greater in rural areas and under a greater threat (higher number of predators approaching) in the afternoon and in the non-breeding season. We also expect a direct relationship between body mass and FID and between FID and FFD. We sampled 11 species after measuring 331 escape behaviors, and we confirmed our predictions for sites (five species), daytime (one species) and rejected our premise about seasons for one species. Mean FID was strongly affected by body mass, and directly affected FFD. Adjustments in FID are, most likely, an important adaptive trait in urban habitats and may partially explain the predominance of species with higher ecological plasticity in cities.(AU)

Conhecimento ecologico local, tomada de decisao e dinamica espacial da frota pesqueira artesanal da Amazonia Central

A pesca artesanal de agua interior ou continental e um componente vital para a vida das pessoas em todo mundo, pois proporciona seguranca nutricional e renda. Entretanto, os recursos pesqueiros sofrem diferencas ameacas, como praticas irresponsaveis de pesca, degradacao do habitat, construcao de barragens, poluicao e mudancas climaticas promovendo declinios substanciais e outras mudancas nos recursos pesqueiros. Esforcos continuos para estabelecer abordagens de gestao eficazes demonstraram que o modelo de co-gestao apresentou potencial de deter os impactos da pesca, por incorporar a participacao do pescador. No entanto, pouca atencao e dada ao comportamento de explotacao do pescador. Nesse contexto, esta tese investigou o conhecimento ecologico local (CEL) dos pescadores artesanais como fonte potencial de dados bio-ecologicos para especies de peixes na Amazonia, a atitude sob risco na escolha dos pesqueiros, a partir da teoria do prospecto. E por fim, compreender a dinamica espacial da frota pesqueira comercial da Amazonia Central como resposta a anomalias negativas hidrologicas. Para investigacao sobre o conhecimento ecologico local dos pescadores foram entrevistados pescadores rurais e urbanos no municipio de Itacoatiara sobre os aspectos bio-ecologicos do pirarucu (Arapaima spp.), tambaqui (Colossoma macropomum) e jaraqui (Semaprochilodus spp.). Para compreender a atitude sob risco dos pescadores comerciais na escolha do pesqueiros foram entrevistados pescadores e encarregados da embarcacao no terminal pesqueiro de Manaus. E para avaliar a dinamica espacial da frota pesqueira da Amazonia Central como resposta as anomalias hidrologicas negativas foi analisada informacoes do Banco de Dados de Monitoramento de estatistica pesqueira, no periodo de 1994 a 2004. Sobre o CEL, nossos resultados demonstram que o LEK dos pescadores representa uma fonte de informacao potencial e confiavel que pode ser usada para fornecer dados sobre peso, comprimento, dimorfismo sexual, dieta, predacao e habitat do pirarucu, tambaqui e jaraqui para apoiar as estrategias de conservacao e gerenciamento. Sobre a tomada de decisao dos pescadores sobre a escolha dos pesqueiros, nossos resultados demonstraram que os pescadores sao avessos as risco, sentindo mais a dor da perda que a satisfacao do ganho, de acordo com a Teoria do Prospecto. Esse comportamento de aversao ao risco e o conhecimento dos pescadores artesanais da Amazonia, deve ser apoiado em politicas de longo prazo para ser um participante ativo, incluindo o cumprimento e a responsabilidade de suas acoes, preocupacoes e necessidades. Os pescadores podem fazer parte de um dialogo continuo com pesquisadores e gerentes como um caminho da justica social, mas tambem da eficiencia do uso e conservacao da biodiversidade. Sobre a dinamica espacial da frota, nossos resultados indicam que a anomalia negativa nao alterou o estado maximo de transformacao espacial da frota de pesca comercial na Amazonia. Entretanto, houve a intensificacao da explotacao do ambiente fluvial proximo a Manaus, focando as especies rio-lacustres que promoveu um aumento na frequencia de viagens e possivel esgotamento do recurso em escala local. Devido a heterogeneidade espacial e ecologica caracteristica do ambiente amazonico, e necessario incorporar analises que considerem a escala espacial nas propostas de gestao da pesca, alem de demonstrar a necessidade e utilidade do monitoramento da pesca em longo prazo. Assim, demonstramos a importancia de incorporar o CEL, a atitude sob risco e a dinamica espacial dos pescadores no modelo de co-gestao para fortalecer as estrategias de conservacao dos recursos pesqueiros no cenario de constante mudancas sociais, economicas e ambientais.

Artisanal inland or continental water fishing is a vital component of people's lives around the world because it provides nutritional security and income. However, fishing resources are threatened by differences such as irresponsible fishing practices, habitat degradation, dam construction, pollution and climate change promoting substantial declines and other changes in fishing resources. Continued efforts to establish effective management approaches have demonstrated that the co-management model has the potential to halt the impacts of fishing by incorporating the participation of fishermen. However, little attention is given to the exploitation behavior of the fisherman. In this context, this thesis investigated the local ecological knowledge (CEL) of artisanal fishers as a potential source of bio-ecological data for fish species in regions of difficult access, such as the Amazon, the attitude under risk in the choice of fishing grounds, from the prospect theory. And finally, to understand the spatial dynamics of the commercial fishing fleet in Central Amazonia as a response to negative hydrological anomalies. For research on the local ecological knowledge of fishers, rural and urban fishermen in the municipality of Itacoatiara were interviewed on the bio-ecological aspects of pirarucu (Arapaima spp.), tambaqui (Colossoma macropomum) and jaraqui (Semaprochilodus spp.). In order to understand the attitude under risk of commercial fishers in the choice of fishing grounds, fishers were interviewed and those in charge of the boat in the Manaus fishing terminal. And to evaluate the spatial dynamics of the Central Amazon fishing fleet as a response to negative hydrological anomalies, information from the Fish Statistics Monitoring Database was analyzed from 1994 to 2004. About the CEL, our results demonstrate that the LEK of fishers represents a potential and reliable source of information that can be used to provide data on weight, length, sexual dimorphism, diet, predation and habitat of pirarucu, tambaqui and jaraqui to support conservation and management strategies. On the fisher's decision making about the choice of fishing grounds, our results have shown that fishermen are averse to risk, feeling more the pain of loss than the satisfaction of gain, according to the prospect theory. This risk-averse behavior and the knowledge of the artisanal fishers of the Amazon must be supported by long-term policies to be an active participant, including compliance and responsibility for their actions, concerns and needs. Fishermen can be part of an ongoing dialogue with researchers and managers as a path to social justice, but also to efficiency in the use and conservation of biodiversity. On the spatial dynamics of the fleet, our results indicate that the negative anomaly has not altered the maximum state of spatial transformation of the commercial fishing fleet in the Amazon. However, there has been an intensification of exploitation of the fluvial environment near Manaus, focusing on the river-lacustrine species that has promoted an increase in the frequency of trips and possible depletion of the resource on a local scale. Due to the characteristic spatial and ecological heterogeneity of the Amazonian environment, it is necessary to incorporate analyses that consider the spatial scale in fisheries management proposals, in addition to demonstrating the need and usefulness of long-term fisheries monitoring. Thus, we demonstrate the importance of incorporating the CEL, the attitude under risk and the spatial dynamics of fishers in the co-management model to strengthen the strategies for conservation of fisheries resources in the scenario of constant social, economic and environmental change.

Zoonoses em cães e gatos atendidos em Projeto de Controle de Natalidade: Toxoplasma gondii, Leishmania spp. e Leptospira spp., sorodiagnóstico e epidemiologia / Zoonosis in dogs and cats attended by the Birth Control Project: Toxoplasma gondii, Leishmania spp. and Leptospira spp., serodiagnosis and epidemiology

A proximidade da relação homem-animal tem aumentado o risco de transmissão de doenças de caráter zoonótico. O objetivo desse trabalho foi determinar a prevalência de anticorpos IgG anti-Toxoplasma gondii, anti- Leishmania spp. e anti- Leptospira spp. nos cães e gatos atendidos pelo Projeto Controle de Natalidade (PCN) nos anos de 2004 a 2012 e verificar a significância estatística de variáveis ambientais e da população de estudo à presença dos agentes infecciosos. Amostras de sangue de 271 cães e 415 gatos foram colhidas por venopunção jugular ou cefálica para a posterior obtenção dos soros. Estes foram submetidos à técnica de imunofluorescência indireta para detecção de anticorpos IgG anti-T. gondii e anti-Leishmania spp. e à técnica de soroaglutinação microscópica para detecção de anticorpos anti- Leptospira spp. A tabulação dos dados foi realizada utilizando-se o pacote estatístico EpiInfo (3.4.3). Dos soros caninos examinados, 20,6% (56/271), 1,3% (3/236) e 21,6% (51/236) foram positivos para T. gondii, Leishmania spp. e Leptospira spp., respectivamente. Encontrou-se maior prevalência de anticorpos anti- T. gondii em cães sem raça definida (p=0, 0009), em cães alimentados com carne crua ou mal cozida (p= 0,0101) e naqueles que não receberam vacina polivalente (p= 0,0147). Não houve associação estatística entre as variáveis avaliadas no questionário epidemiológico para leishmaniose e leptospirose. Dos soros felinos analisados, 20,9% (87/415) foram positivos para T. gondii. Maiores prevalências foram observadas nos felinos com hábito de caçar roedores (p= 0,0388) e que não recebem água tratada (p= 0,0294). Os resultados obtidos confirmam a importância dos fatores de risco ingestão de carne crua ou mal cozida, ingestão de água não tratada e predação de roedores para infecção por T. gondii. Demonstrou-se baixa prevalência ao sorodiagnostico para Leishmania spp. Os sorovares de Leptospira spp. mais frequentes foram Copenhageni, Canicola e Butembo.(AU)

Increasing human-animal proximity has also increased risks of zoonotic disease transmission. This study measured the prevalence of anti-Toxoplasma gondii, anti-Leishmania spp. and anti-Leptospira spp. IgG antibodies in dogs and cats attended by the Birth Control Project (BCP) from 2004 to 2012 to determine which environmental variables were significantly associated with infectious agents in the study population. Blood samples from 271 dogs and 415 cats were collected by jugular or cephalic venipuncture for serological analysis. Indirect immunofluorescence assays were used to detect anti-T. gondii and anti-Leishmania spp. IgG antibodies and microscopic serum-agglutination tests were used to detect anti- Leptospira spp. antibodies. Data tabulation and statistical analyses were performed using EpiInfo (3.4.3). Among canine sera samples, 20.6% (56/271), 1.3% (3/236), and 21.6% (51/236) were positive for T. gondii, Leishmania spp., and Leptospira spp., respectively. Higher T. gondii prevalence was found in dogs of unknown breeding history (p=0.0009), those fed raw or undercooked meat (p=0.0101), and those that did not receive the polyvalent vaccine (p=0.0147). There was no statistically significant association between leishmaniosis and leptospirosis and variables evaluated in the epidemiological questionnaire. Among feline sera samples, 20.9% (87/415) were positive for T. gondii. The highest prevalence rates were observed in felines that hunted rodents (p=0.0388) and that consumed untreated water (p=0.0294). These results confirmed that ingestion of raw or undercooked meat, drinking untreated water, and predation of rodents were important risk factors for T. gondii infection. A low Leishmania spp. serodiagnostic prevalence was observed. The most frequent Leptospira spp. serovars were Copenhageni, Canicola, and Butembo.(AU)

Efeito da Metionina e o risco de predação na fisiologia, genética e sobrevivência do Zebrafish (Danio rerio)

A metionina é um aminoácido limitante em dietas comerciais na maioria dos peixes, e sua insuficiência além de causar limitação no crescimento, pode reduzir a eficiência alimentar, e pode afetar o sistema oxidante do organismo. Nesse sentido, os objetivos deste trabalho foram avaliar o efeito da metionina e o risco de predação no desempenho, histologia intestinal, cortisol, expressão gênica e sobrevivência do zebrafish (Danio rerio). No primeiro experimento, 360 animais de um ano de idade foram divididos em três tratamentos relacionados à suplementação de metionina: Sem suplementação de metionina (SM); suplementada com DL-Metionina 99% - aminoácido na sua forma livre (DL) e suplementada com metionina na forma dipeptídeo DL-Metionil-DL-Metionina 95% (MM). Os peixes foram mantidos sem contato com predador no aquário (SO) ou com contato direto com predador no aquário (CO), por 48 horas ou 20 dias, dependendo da fase experimental avaliada. O estresse por risco de predação reduziu o ganho de peso dos animais com 20 dias e os peixes alimentados com suplementação de metionina, independente da fonte utilizada, apresentaram ganho de peso superiores quando comparados aos SM. Não houve diferença estatística nos niveis de cortisol em função do risco de predação e da suplementação de metionina. Não houve efeito significativo da interação entre o risco de predação e a suplementação de metionina, para o gene PEPT1. Os peixes com 48 horas de exposição ao estresse, com risco de predação, apresentaram maior expressão do mRNA dos genes SOD2, CAT e GPX1. Em relação ao consumo prolongado das dietas, observou-se menor expressão desses genes em animais consumindo dietas DL e MM. No segundo experimento, os reprodutores e sua prole, receberam exclusivamente ração formulada com ingredientes convencionais suplementados com metionina: DL, MM e um tratamento controle sem suplementação de metionina (SM). Através do monitoramento continuo dos animais, após eclosão, observou-se que as larvas abriram a boca com 3 dias pós-fertilização (dpf) e a partir desse momento, iniciou-se a alimentação com 3 e 5 dpf para avaliar a sobrevivência das larvas em função das dietas dos pais até 20 dpf. Para realização do experimento, zebrafish proveniente de programa de melhoramento genético, foram utilizados para a obtenção dos ovos. 1200 larvas com 3 dpf foram divididos em três tratamentos relacionados à suplementação de metionina: SM, DL e MM seguindo a mesma dieta que seus pais. Os animais tiveram 2 períodos de início de alimentação com 3 ou 5 dpf. Não se observou diferença significativa na taxa de sobrevivência entre o início da alimentação com 3 ou 5 dpf. Através da literatura consultada essa é a primeira vez que esse fato é relatado em zebrafish consumindo dietas formuladas exclusivamente com ingredientes convencionais. Observou-se também que independente da fonte de metionina utilizada, a sobrevivência foi maior em larvas dos tratamentos DL e MM. Em conclusão, a suplementação com metionina é fundamental para garantir tolerancia celular, fornecendo poder redutor para os sistemas antioxidantes, que é responsável por neutralizar os radicais livre. Além de auxiliar na geração de larvas precoces para capacidade de ingerir alimentos e garantir maior sobrevivência dessas formas jovens.

Methionine is a limiting amino acid in commercial diets in most of fish, and its insufficiency can cause growth restriction, reduce feed efficiency, and can affect the body's antioxidant system. The objective of this study was to evaluate the effect of methionine and the risk of predation on the performance, intestinal histology, cortisol, gene expression and survival of zebrafish (Danio rerio). In the first experiment, 360 one-year-old animals were divided into three treatments related to methionine supplementation: no methionine supplementation (SM); supplemented with DL methionine 99% -amino acid in free form (DL) and supplemented with methionine in the dipeptide form DL-Methionyl-DL-Methionine 95% (MM). Fish were kept without contact with the predator in the aquarium (SO) or with direct contact with predator in the aquarium (CO), for 48 hours or 20 days, depending on the experimental phase evaluated. Stress due to predation risk reduced the weight gain of animals with 20 days and the fish fed with methionine supplementation, regardless of the source used, presented higher weight gain when compared to SM. There was no statistical difference in cortisol levels due to the risk of predation and methionine supplementation. There was no significant effect on the interaction between the risk of predation and methionine supplementation, for PEPT1 gene. Fish with 48 hours of exposure to stress with risk of predation presented higher mRNA expression of the SOD2, CAT and GPX1 genes. In relation to prolonged consumption of the diets, lower expression of these genes in animals consuming diets DL and MM was observed. In the second experiment, breeders and their offspring, received exclusively feed formulated with conventional ingredients supplemented with methionine: DL, MM and a control treatment without methionine supplementation (SM). Through the continuous monitoring of the animals after hatching, it was observed that the larvae opened their mouth 3 days post fertilization (dpf), and from this moment, feeding started with 3 and 5 dpf to evaluate the survival of the larvae, according to the parents' diets, until 20 dpf. For the experiment, zebrafish from a breeding program were used to obtain the eggs. 1200 larvae at 3 dpf were divided into three treatments related to methionine supplementation: SM, DL and MM, following the same diet as their parents. The animals had two periods for the beginning of feeding, with 3 or 5 dpf. No significant difference in the survival rate between the beginning of feeding with 3 or 5 dpf was observed. Through literature consulted, this is the first time that this fact is reported in zebrafish consuming diets formulated exclusively with conventional ingredients. We also observed that, regardless of the source of methionine used, survival was higher in larvae of DL and MM treatments. In conclusion, methionine supplementation is important to ensure cell tolerance, providing reducing power for antioxidant systems, which is responsible for neutralizing free radicals, besides helping in the generation of early larvae ability to ingest food and ensure greater survival of these young forms.

Avaliação de risco e plasticidade comportamental limitada em girinos de Rhinella ornata (Anura, Bufonidae) / Assessment risk and limited behavioral plasticity in tadpoles of Rhinella ornata (Anura, Bufonidae)

Anuran tadpoles are important elements of trophic networks in aquatic environments, being food resource for many types of predators. Thus, the tadpoles exhibit a great variety of defense mechanisms that may be morphological, behavioral and/or physiological. The unpalatability, produced by the accumulation of toxic substances in the skin, is a common mechanism in many frog lineages. However, some predators are not affected by these toxic substances, which may favor the development of alternative mechanisms of defense against predation. In this context, our objective was evaluate if the unpalatable tadpoles of Rhinella ornata (Spix, 1824) may present behavioral mechanisms of defense against predation in the presence of predators that are not affected by toxic substances on its skin. To test our hypothesis, we used two kinds of predators: an aquatic Heteroptera of the genus Belostoma and a dragonfly larva of the genus Aeshna. The tadpoles were located in aquariums with visual and chemical clues of predators (direct risk experiment), only chemical clues (indirect risk experiment) and by the complete absence of predator signals (control). In both cases, the swimming behavior was observed for 5 minutes. During the experiments there was no alteration in swimming behavior of tadpoles.(AU)

Os girinos de anuros são elementos importantes das redes tróficas de ambientes aquáticos, sendo recurso alimentar de diversos tipos de predadores. Desta maneira, os girinos apresentam uma grande variedade de mecanismos de defesa que podem ser morfológicos, comportamentais e/ ou fisiológicos. A impalatabilidade, produzida pelo acúmulo de substâncias tóxicas na pele, é um mecanismo comum em muitas linhagens de anfíbios. No entanto, alguns predadores não são afetados por estas substâncias tóxicas, o que pode favorecer o desenvolvimento de mecanismos alternativos de defesa contra predação. Neste contexto, nosso objetivo foi avaliar se girinos impalatáveis de Rhinella ornata (Spix, 1824), podem apresentar mecanismos comportamentais de defesa contra predação na presença de predadores que não são afetados pelas substâncias tóxicas em sua pele. Para testar nossa hipótese, utilizamos dois tipos de predadores aquáticos: um heteróptero aquático do gênero Belostoma e uma larva de libélula do gênero Aeshna. Os girinos foram colocados em aquários com pistas visuais e químicas dos predadores (experimento de risco direto), somente pistas químicas (experimento de risco indireto) e ausência completa de sinais de predadores (controle). Em ambos os casos, o comportamento de natação foi observado durante 5 minutos. Durante os experimentos não houve alteração no comportamento de natação dos girinos.(AU)

Avaliação de risco e plasticidade comportamental limitada em girinos de Rhinella ornata (Anura, Bufonidae) / Assessment risk and limited behavioral plasticity in tadpoles of Rhinella ornata (Anura, Bufonidae)

Anuran tadpoles are important elements of trophic networks in aquatic environments, being food resource for many types of predators. Thus, the tadpoles exhibit a great variety of defense mechanisms that may be morphological, behavioral and/or physiological. The unpalatability, produced by the accumulation of toxic substances in the skin, is a common mechanism in many frog lineages. However, some predators are not affected by these toxic substances, which may favor the development of alternative mechanisms of defense against predation. In this context, our objective was evaluate if the unpalatable tadpoles of Rhinella ornata (Spix, 1824) may present behavioral mechanisms of defense against predation in the presence of predators that are not affected by toxic substances on its skin. To test our hypothesis, we used two kinds of predators: an aquatic Heteroptera of the genus Belostoma and a dragonfly larva of the genus Aeshna. The tadpoles were located in aquariums with visual and chemical clues of predators (direct risk experiment), only chemical clues (indirect risk experiment) and by the complete absence of predator signals (control). In both cases, the swimming behavior was observed for 5 minutes. During the experiments there was no alteration in swimming behavior of tadpoles.

Os girinos de anuros são elementos importantes das redes tróficas de ambientes aquáticos, sendo recurso alimentar de diversos tipos de predadores. Desta maneira, os girinos apresentam uma grande variedade de mecanismos de defesa que podem ser morfológicos, comportamentais e/ ou fisiológicos. A impalatabilidade, produzida pelo acúmulo de substâncias tóxicas na pele, é um mecanismo comum em muitas linhagens de anfíbios. No entanto, alguns predadores não são afetados por estas substâncias tóxicas, o que pode favorecer o desenvolvimento de mecanismos alternativos de defesa contra predação. Neste contexto, nosso objetivo foi avaliar se girinos impalatáveis de Rhinella ornata (Spix, 1824), podem apresentar mecanismos comportamentais de defesa contra predação na presença de predadores que não são afetados pelas substâncias tóxicas em sua pele. Para testar nossa hipótese, utilizamos dois tipos de predadores aquáticos: um heteróptero aquático do gênero Belostoma e uma larva de libélula do gênero Aeshna. Os girinos foram colocados em aquários com pistas visuais e químicas dos predadores (experimento de risco direto), somente pistas químicas (experimento de risco indireto) e ausência completa de sinais de predadores (controle). Em ambos os casos, o comportamento de natação foi observado durante 5 minutos. Durante os experimentos não houve alteração no comportamento de natação dos girinos.