RESUMO

Desmodus rotundus, vampire bats, transmit dangerous infections, and brucellosis is a hazardous zoonotic disease, two adversities that coexist in the subtropical and tropical areas of the American continent. Here, we report a 47.89% Brucella infection prevalence in a colony of vampire bats inhabiting the tropical rainforest of Costa Rica. The bacterium induced placentitis and fetal death in bats. Wide-range phenotypic and genotypic characterization placed the Brucella organisms as a new pathogenic species named Brucella nosferati sp. nov., isolated from bat tissues, including the salivary glands, suggesting feeding behavior might favor transmission to their prey. Overall analyses placed B. nosferati as the etiological agent of a reported canine brucellosis case, demonstrating its potential for infecting other hosts. To assess the putative prey hosts, we analyzed the intestinal contents of 14 infected and 23 non-infected bats by proteomics. A total of 54,508 peptides sorted into 7,203 unique peptides corresponding to 1,521 proteins were identified. Twenty-three wildlife and domestic taxa, including humans, were foraged by B. nosferati-infected D. rotundus, suggesting contact of this bacterium with a broad range of hosts. Our approach is appropriate for detecting, in a single study, the prey preferences of vampire bats in a diverse area, demonstrating its suitability for control strategies where vampire bats thrive. IMPORTANCE The discovery that a high proportion of vampire bats in a tropical area is infected with pathogenic Brucella nosferati and that bats forage on humans and many wild and domestic animals is relevant from the perspective of emerging disease prevention. Indeed, bats harboring B. nosferati in their salivary glands may transmit this pathogenic bacterium to other hosts. This potential is not trivial since, besides the demonstrated pathogenicity, this bacterium possesses all the required virulent arsenal of dangerous Brucella organisms, including those that are zoonotic for humans. Our work has settled the basis for future surveillance actions in brucellosis control programs where these infected bats thrive. Moreover, our strategy to identify the foraging range of bats may be adapted for exploring the feeding habits of diverse animals, including arthropod vectors of infectious diseases, and therefore of interest to a broader audience besides experts on Brucella and bats.

Assuntos

RESUMO

Food webs usually display an intricate mix of trophic interactions where multiple prey are common. In this context omnivory has been the subject of intensive analysis regarding food web stability and structure. In a three species omnivory setting it is shown that the modeling of prey preference by the top predator may exert a strong influence on the short as well as on the long term dynamics of the respective food web. Clearly, this has implications concerning the stability and the structure of omnivory systems under disturbances such as nutrient enrichment.

Redes tróficas apresentam geralmente uma variada rede de interações onde múltiplas presas são comuns. Neste contexto, a onivoria vem sendo objeto de intensas análises à luz da estabilidade e estrutura do sistema. A modelagem do termo de preferência pelo predador de topo sobre suas presas pode exercer uma forte influência sobre as dinâmicas transiente e de longo prazo em uma rede trófica onívora composta por três espécies. Claramente, isto tem implicações sobre a estrutura e estabilidade do sistema sob distúrbios tais como o enriquecimento por nutrientes.

Assuntos

RESUMO

Food webs usually display an intricate mix of trophic interactions where multiple prey are common. In this context omnivory has been the subject of intensive analysis regarding food web stability and structure. In a three species omnivory setting it is shown that the modeling of prey preference by the top predator may exert a strong influence on the short as well as on the long term dynamics of the respective food web. Clearly, this has implications concerning the stability and the structure of omnivory systems under disturbances such as nutrient enrichment.

Redes tróficas apresentam geralmente uma variada rede de interações onde múltiplas presas são comuns. Neste contexto, a onivoria vem sendo objeto de intensas análises à luz da estabilidade e estrutura do sistema. A modelagem do termo de preferência pelo predador de topo sobre suas presas pode exercer uma forte influência sobre as dinâmicas transiente e de longo prazo em uma rede trófica onívora composta por três espécies. Claramente, isto tem implicações sobre a estrutura e estabilidade do sistema sob distúrbios tais como o enriquecimento por nutrientes.

RESUMO

Land flatworms are carnivorous, mainly predators. However, knowledge on their predatory behavior and prey preference is very scarce. This paucity of data is a limiting factor in the study of their biology and organismal ecology, resulting in a very difficult task to breed them in the laboratory for prolonged periods if prey preference and predation frequency are unknown. We investigated the predatory behavior of Notogynaphallia abundans (Graff, 1899), Geoplaninae, based on laboratory experiments. In order to determine its predatory choices, we offered mollusks, earthworms, arthropods, and other land flatworms. Only land isopods were accepted, with an average consumption of 3.4 individuals per week. Linear regression showed a positive relationship between the number of consumed isopods and the increase/decrease in body mass. Consumption resulting in an increase in body mass was ca. four isopods per week. Predatory behavior, with a mean time-span of 28 min 45 s ± 15 min 47 s, includes encounter and capture of prey, immobilization, handling and feeding. Variation in the duration of this activity in N. abundans is clearly due to variations in the time necessary for transferring the prey from either the anterior or posterior thirds of the body to the mouth, as well as for external digestion and ingestion. In order to capture very active and fast-moving animals such as land isopods, N. abundans employs various strategies, using either the anterior or the posterior body regions to press the prey against the ground or against its own body, thus allowing it to deal with various responses by the prey, and thereby maximizing predatory success. Similar to other flatworms, both physical holding and entrapment in a mucous secretion are of fundamental importance for prey-immobilization. The different strategies employed by land flatworms in their predatory behavior are discussed, and behavioral plasticity in the capture and immobilization of prey in different platyhelminth groups is emphasized.

RESUMO

Land flatworms are carnivorous, mainly predators. However, knowledge on their predatory behavior and prey preference is very scarce. This paucity of data is a limiting factor in the study of their biology and organismal ecology, resulting in a very difficult task to breed them in the laboratory for prolonged periods if prey preference and predation frequency are unknown. We investigated the predatory behavior of Notogynaphallia abundans (Graff, 1899), Geoplaninae, based on laboratory experiments. In order to determine its predatory choices, we offered mollusks, earthworms, arthropods, and other land flatworms. Only land isopods were accepted, with an average consumption of 3.4 individuals per week. Linear regression showed a positive relationship between the number of consumed isopods and the increase/decrease in body mass. Consumption resulting in an increase in body mass was ca. four isopods per week. Predatory behavior, with a mean time-span of 28 min 45 s ± 15 min 47 s, includes encounter and capture of prey, immobilization, handling and feeding. Variation in the duration of this activity in N. abundans is clearly due to variations in the time necessary for transferring the prey from either the anterior or posterior thirds of the body to the mouth, as well as for external digestion and ingestion. In order to capture very active and fast-moving animals such as land isopods, N. abundans employs various strategies, using either the anterior or the posterior body regions to press the prey against the ground or against its own body, thus allowing it to deal with various responses by the prey, and thereby maximizing predatory success. Similar to other flatworms, both physical holding and entrapment in a mucous secretion are of fundamental importance for prey-immobilization. The different strategies employed by land flatworms in their predatory behavior are discussed, and behavioral plasticity in the capture and immobilization of prey in different platyhelminth groups is emphasized.

RESUMO

Land flatworms are carnivorous, mainly predators. However, knowledge on their predatory behavior and prey preference is very scarce. This paucity of data is a limiting factor in the study of their biology and organismal ecology, resulting in a very difficult task to breed them in the laboratory for prolonged periods if prey preference and predation frequency are unknown. We investigated the predatory behavior of Notogynaphallia abundans (Graff, 1899), Geoplaninae, based on laboratory experiments. In order to determine its predatory choices, we offered mollusks, earthworms, arthropods, and other land flatworms. Only land isopods were accepted, with an average consumption of 3.4 individuals per week. Linear regression showed a positive relationship between the number of consumed isopods and the increase/decrease in body mass. Consumption resulting in an increase in body mass was ca. four isopods per week. Predatory behavior, with a mean time-span of 28 min 45 s ± 15 min 47 s, includes encounter and capture of prey, immobilization, handling and feeding. Variation in the duration of this activity in N. abundans is clearly due to variations in the time necessary for transferring the prey from either the anterior or posterior thirds of the body to the mouth, as well as for external digestion and ingestion. In order to capture very active and fast-moving animals such as land isopods, N. abundans employs various strategies, using either the anterior or the posterior body regions to press the prey against the ground or against its own body, thus allowing it to deal with various responses by the prey, and thereby maximizing predatory success. Similar to other flatworms, both physical holding and entrapment in a mucous secretion are of fundamental importance for prey-immobilization. The different strategies employed by land flatworms in their predatory behavior are discussed, and behavioral plasticity in the capture and immobilization of prey in different platyhelminth groups is emphasized.

RESUMO

Land flatworms are carnivorous, mainly predators. However, knowledge on their predatory behavior and prey preference is very scarce. This paucity of data is a limiting factor in the study of their biology and organismal ecology, resulting in a very difficult task to breed them in the laboratory for prolonged periods if prey preference and predation frequency are unknown. We investigated the predatory behavior of Notogynaphallia abundans (Graff, 1899), Geoplaninae, based on laboratory experiments. In order to determine its predatory choices, we offered mollusks, earthworms, arthropods, and other land flatworms. Only land isopods were accepted, with an average consumption of 3.4 individuals per week. Linear regression showed a positive relationship between the number of consumed isopods and the increase/decrease in body mass. Consumption resulting in an increase in body mass was ca. four isopods per week. Predatory behavior, with a mean time-span of 28 min 45 s ± 15 min 47 s, includes encounter and capture of prey, immobilization, handling and feeding. Variation in the duration of this activity in N. abundans is clearly due to variations in the time necessary for transferring the prey from either the anterior or posterior thirds of the body to the mouth, as well as for external digestion and ingestion. In order to capture very active and fast-moving animals such as land isopods, N. abundans employs various strategies, using either the anterior or the posterior body regions to press the prey against the ground or against its own body, thus allowing it to deal with various responses by the prey, and thereby maximizing predatory success. Similar to other flatworms, both physical holding and entrapment in a mucous secretion are of fundamental importance for prey-immobilization. The different strategies employed by land flatworms in their predatory behavior are discussed, and behavioral plasticity in the capture and immobilization of prey in different platyhelminth groups is emphasized.

RESUMO

Land flatworms are carnivorous, mainly predators. However, knowledge on their predatory behavior and prey preference is very scarce. This paucity of data is a limiting factor in the study of their biology and organismal ecology, resulting in a very difficult task to breed them in the laboratory for prolonged periods if prey preference and predation frequency are unknown. We investigated the predatory behavior of Notogynaphallia abundans (Graff, 1899), Geoplaninae, based on laboratory experiments. In order to determine its predatory choices, we offered mollusks, earthworms, arthropods, and other land flatworms. Only land isopods were accepted, with an average consumption of 3.4 individuals per week. Linear regression showed a positive relationship between the number of consumed isopods and the increase/decrease in body mass. Consumption resulting in an increase in body mass was ca. four isopods per week. Predatory behavior, with a mean time-span of 28 min 45 s ± 15 min 47 s, includes encounter and capture of prey, immobilization, handling and feeding. Variation in the duration of this activity in N. abundans is clearly due to variations in the time necessary for transferring the prey from either the anterior or posterior thirds of the body to the mouth, as well as for external digestion and ingestion. In order to capture very active and fast-moving animals such as land isopods, N. abundans employs various strategies, using either the anterior or the posterior body regions to press the prey against the ground or against its own body, thus allowing it to deal with various responses by the prey, and thereby maximizing predatory success. Similar to other flatworms, both physical holding and entrapment in a mucous secretion are of fundamental importance for prey-immobilization. The different strategies employed by land flatworms in their predatory behavior are discussed, and behavioral plasticity in the capture and immobilization of prey in different platyhelminth groups is emphasized.

RESUMO

The spider Misumenops pallidus (Thomisidae) is commonly found in alfalfa crops. We studied its predatory preferences on potential insect prey, particularly regarding agroecosystems pests. Two kinds of tests were done under normal laboratory conditions: simultaneous presentation of prey (n = 215) and alternative prey test (n = 45). The spiders preferred insects that were mobile, small, without defensive glands and with thin exoskeletons. According to the amount of prey consumed, we established four predation levels: high (> 55%, on adult Drosophila melanogaster flies); intermediate (30%-55% on the defoliator larvae of Rachiplusia nu and adult heteropterans: Horciasinus argentinus and Halticus spegazzinii); and low (10%-30% on the chrysomelids Colapsis sp. and Diabrotica speciosa). The pentatomid Piezodorus guildinii, the curculionid Naupactus sp. and the aphid Acyrthosiphom pisum were not accepted as food. Once the spider captured a prey item it did not accept another, independently of prey item species (82% of trials).

Se analizó la preferencia alimentaria de la araña Misumenops pallidus frente a diferentes potenciales insectos presas, algunos de los cuales son plaga en cultivos agrícolas. Se efectuaron pruebas de presentación simultánea de presas (n= 215) y de presa alternativa (n= 45), en condiciones normales de laboratorio. M. pallidus mostró predilección por insectos móviles, pequeños, de exoesqueleto delgado y sin glándulas repelentes. Se establecieron cuatro niveles de depredación. El grado máximo (> 55%) correspondió a las moscas adultas Drosophila melanogaster. Hubo depredación intermedia (30%-55%) de larvas desfoliadoras (Rachiplusia nu) y heterópteros adultos (Horciasinus argentinus y Halticus spegazzinii); y depredación mínima (10%-30%) de los crisomélidos Colaspis sp. y Diabrotica speciosa. Los pentatómidos Piezodorus guildinii, los curculiónidos Naupactus sp. y los áfidos Acyrthosiphom pisum, no fueron depredados. En el 82% de los casos, una vez que M. pallidus logra cazar su presa, no la cambia por otra (independientemente del tipo de presa considerada).

Assuntos