ABSTRACT
Sucking pests are major threat to cotton field crop which cause unbearable losses to the crop yield. Aim of the current study was to record seasonal dynamics of major sucking insect pests including whitefly, jassid, thrips and their natural arthropod predators i.e. green lacewings and spiders in cotton field plots. The effects of surrounding field crops on pests' density and predatory efficiency of predators were also recorded. For sampling and survey of insects, the visual counting was found to be the most efficient method for recording the abundance of insects, trailed by net sweeping and tapping. Whitefly was the most dominant sucking pest found on the vegetative stage of cotton, followed by jassid and thrips. Fluctuated populations of predatory arthropods, spiders and green lacewings were also recorded during whole cropping season however, the densities of pests and predators varied with crop phenology. Spiders' population was encouraging at both vegetative and flowering stage and also the same trend of jassid and whitefly were observed at both stages of the crop. Surrounding habitats showed non-significant effect on population densities of insect pests and predators. For abiotic factors, the spiders showed strong positive correlation with humidity and temperature. However, green lacewing was only positively correlated with humidity. On the other hand, the populations of whitefly, jassid and thrips showed non-significant correlation with both temperature and humidity. Overall densities of sucking insect pests were found above economic threshold level. The plant age, crop stage and surrounding habitats effect on the population fluctuation of pests as well as the predators' abundance. The future studies are also warranted to investigate the altered habitats and multiple trap cropping to find out their impact on unattended insect predators and parasitoids in cotton crop.
As pragas sugadoras são uma grande ameaça para a cultura do algodão, causando perdas insuportáveis no rendimento da cultura. O objetivo do estudo atual foi registrar a dinâmica sazonal das principais pragas de insetos sugadores, incluindo mosca-branca, jassid, tripes e seus artrópodes predadores naturais, ou seja, crisopídeos e aranhas verdes em parcelas de algodão. Os efeitos das plantações circundantes na densidade de pragas e na eficiência predatória de predadores também foram registrados. Para amostragem e pesquisa de insetos, a contagem visual foi considerada o método mais eficiente para registrar a abundância de insetos, seguido por varredura e batida de rede. A mosca-branca foi a praga sugadora mais dominante encontrada na fase vegetativa do algodoeiro, seguida pelo jassid e tripes. Populações flutuantes de artrópodes predadores, aranhas e crisálidas também foram registradas durante toda a safra, no entanto as densidades de pragas e predadores variaram com a fenologia da cultura. A população de aranhas foi encorajadora tanto na fase vegetativa como na floração e também a mesma tendência de jassid e mosca-branca foi observada em ambas as fases da cultura. Os habitats circundantes mostraram efeito não significativo nas densidades populacionais de insetos-praga e predadores. Para os fatores abióticos, as aranhas apresentaram forte correlação positiva com umidade e temperatura. No entanto, lacewing verde foi apenas positivamente correlacionado com a umidade. Por outro lado, as populações de mosca-branca, jassid e tripes apresentaram correlação não significativa com temperatura e umidade. As densidades gerais de pragas sugadoras de insetos foram encontradas acima do nível do limiar econômico. A idade da planta, o estágio da cultura e os habitats circundantes afetam a flutuação populacional de pragas, bem como a abundância de predadores. Os estudos futuros também são necessários para investigar os habitats alterados e cultivo com armadilhas múltiplas [...].
Subject(s)
Arthropods , Diptera , Seasons , Gossypium/parasitology , Hemiptera , Agricultural PestsABSTRACT
Abstract Sucking pests are major threat to cotton field crop which cause unbearable losses to the crop yield. Aim of the current study was to record seasonal dynamics of major sucking insect pests including whitefly, jassid, thrips and their natural arthropod predators i.e. green lacewings and spiders in cotton field plots. The effects of surrounding field crops on pests density and predatory efficiency of predators were also recorded. For sampling and survey of insects, the visual counting was found to be the most efficient method for recording the abundance of insects, trailed by net sweeping and tapping. Whitefly was the most dominant sucking pest found on the vegetative stage of cotton, followed by jassid and thrips. Fluctuated populations of predatory arthropods, spiders and green lacewings were also recorded during whole cropping season however, the densities of pests and predators varied with crop phenology. Spiders population was encouraging at both vegetative and flowering stage and also the same trend of jassid and whitefly were observed at both stages of the crop. Surrounding habitats showed non-significant effect on population densities of insect pests and predators. For abiotic factors, the spiders showed strong positive correlation with humidity and temperature. However, green lacewing was only positively correlated with humidity. On the other hand, the populations of whitefly, jassid and thrips showed non-significant correlation with both temperature and humidity. Overall densities of sucking insect pests were found above economic threshold level. The plant age, crop stage and surrounding habitats effect on the population fluctuation of pests as well as the predators abundance. The future studies are also warranted to investigate the altered habitats and multiple trap cropping to find out their impact on unattended insect predators and parasitoids in cotton crop.
Resumo As pragas sugadoras são uma grande ameaça para a cultura do algodão, causando perdas insuportáveis no rendimento da cultura. O objetivo do estudo atual foi registrar a dinâmica sazonal das principais pragas de insetos sugadores, incluindo mosca-branca, jassid, tripes e seus artrópodes predadores naturais, ou seja, crisopídeos e aranhas verdes em parcelas de algodão. Os efeitos das plantações circundantes na densidade de pragas e na eficiência predatória de predadores também foram registrados. Para amostragem e pesquisa de insetos, a contagem visual foi considerada o método mais eficiente para registrar a abundância de insetos, seguido por varredura e batida de rede. A mosca-branca foi a praga sugadora mais dominante encontrada na fase vegetativa do algodoeiro, seguida pelo jassid e tripes. Populações flutuantes de artrópodes predadores, aranhas e crisálidas também foram registradas durante toda a safra, no entanto as densidades de pragas e predadores variaram com a fenologia da cultura. A população de aranhas foi encorajadora tanto na fase vegetativa como na floração e também a mesma tendência de jassid e mosca-branca foi observada em ambas as fases da cultura. Os habitats circundantes mostraram efeito não significativo nas densidades populacionais de insetos-praga e predadores. Para os fatores abióticos, as aranhas apresentaram forte correlação positiva com umidade e temperatura. No entanto, lacewing verde foi apenas positivamente correlacionado com a umidade. Por outro lado, as populações de mosca-branca, jassid e tripes apresentaram correlação não significativa com temperatura e umidade. As densidades gerais de pragas sugadoras de insetos foram encontradas acima do nível do limiar econômico. A idade da planta, o estágio da cultura e os habitats circundantes afetam a flutuação populacional de pragas, bem como a abundância de predadores. Os estudos futuros também são necessários para investigar os habitats alterados e cultivo com armadilhas múltiplas para descobrir seu impacto sobre predadores de insetos e parasitoides desacompanhados na cultura do algodão.
ABSTRACT
Sucking pests are major threat to cotton field crop which cause unbearable losses to the crop yield. Aim of the current study was to record seasonal dynamics of major sucking insect pests including whitefly, jassid, thrips and their natural arthropod predators i.e. green lacewings and spiders in cotton field plots. The effects of surrounding field crops on pests' density and predatory efficiency of predators were also recorded. For sampling and survey of insects, the visual counting was found to be the most efficient method for recording the abundance of insects, trailed by net sweeping and tapping. Whitefly was the most dominant sucking pest found on the vegetative stage of cotton, followed by jassid and thrips. Fluctuated populations of predatory arthropods, spiders and green lacewings were also recorded during whole cropping season however, the densities of pests and predators varied with crop phenology. Spiders' population was encouraging at both vegetative and flowering stage and also the same trend of jassid and whitefly were observed at both stages of the crop. Surrounding habitats showed non-significant effect on population densities of insect pests and predators. For abiotic factors, the spiders showed strong positive correlation with humidity and temperature. However, green lacewing was only positively correlated with humidity. On the other hand, the populations of whitefly, jassid and thrips showed non-significant correlation with both temperature and humidity. Overall densities of sucking insect pests were found above economic threshold level. The plant age, crop stage and surrounding habitats effect on the population fluctuation of pests as well as the predators' abundance. The future studies are also warranted to investigate the altered habitats and multiple trap cropping to find out their impact on unattended insect predators and parasitoids in cotton crop.
As pragas sugadoras são uma grande ameaça para a cultura do algodão, causando perdas insuportáveis no rendimento da cultura. O objetivo do estudo atual foi registrar a dinâmica sazonal das principais pragas de insetos sugadores, incluindo mosca-branca, jassid, tripes e seus artrópodes predadores naturais, ou seja, crisopídeos e aranhas verdes em parcelas de algodão. Os efeitos das plantações circundantes na densidade de pragas e na eficiência predatória de predadores também foram registrados. Para amostragem e pesquisa de insetos, a contagem visual foi considerada o método mais eficiente para registrar a abundância de insetos, seguido por varredura e batida de rede. A mosca-branca foi a praga sugadora mais dominante encontrada na fase vegetativa do algodoeiro, seguida pelo jassid e tripes. Populações flutuantes de artrópodes predadores, aranhas e crisálidas também foram registradas durante toda a safra, no entanto as densidades de pragas e predadores variaram com a fenologia da cultura. A população de aranhas foi encorajadora tanto na fase vegetativa como na floração e também a mesma tendência de jassid e mosca-branca foi observada em ambas as fases da cultura. Os habitats circundantes mostraram efeito não significativo nas densidades populacionais de insetos-praga e predadores. Para os fatores abióticos, as aranhas apresentaram forte correlação positiva com umidade e temperatura. No entanto, lacewing verde foi apenas positivamente correlacionado com a umidade. Por outro lado, as populações de mosca-branca, jassid e tripes apresentaram correlação não significativa com temperatura e umidade. As densidades gerais de pragas sugadoras de insetos foram encontradas acima do nível do limiar econômico. A idade da planta, o estágio da cultura e os habitats circundantes afetam a flutuação populacional de pragas, bem como a abundância de predadores. Os estudos futuros também são necessários para investigar os habitats alterados e cultivo com armadilhas múltiplas para descobrir seu impacto sobre predadores de insetos e parasitoides desacompanhados na cultura do algodão.
Subject(s)
Animals , Spiders , Gossypium , Pakistan , Ecosystem , InsectaABSTRACT
ABSTRACT Describing dung beetle communities in tropical forest remnants located in disturbed/urbanized and conserved areas can provide information about the functioning of these ecosystems and support conservation plans. This study aimed to verify the effect of seasons and bait type on dung beetle communities in remnants of the Atlantic Forest in order to describe their composition and diversity parameters. The study was carried out during both the rainy and dry seasons in periurban and urban remnants. Eighteen pitfall traps baited with feces, carrion, and injured millipedes were established in each site. A total of 3501 individuals and 23 species were recorded. Urban remnant presented higher abundance of individuals in the dry season. On the other hand, in periurban remnant the higher abundance was verified in the rainy season. The diversity was higher in the rainy season in both sites. In urban remnant, Coprophanaeus ensifer was found to be generalist regarding its choice of bait (feces and carrion). The use of injured millipedes as bait allowed the record of the predatory species Deltochilum alpercata. Among the types of bait used, the injured millipedes proved to be very effective, capturing a greater diversity of dung beetles during the rainy season in both remnants, and allowed the collection of specialized, necrophages, and generalists species. Therefore, we propose the use of mixed-bait sampling designs in inventories and surveys to increase the chances of sampling species with different traits or dietary preferences, which are often rare in collections.
ABSTRACT
ABSTRACT The Channel-billed Toucan (Ramphastos vitellinus) is an omnivorous bird that eventually is nest-robbers. Several birdsongs display anti-predatory strategies such as attacks and mobbing calls to face this kind of predator. This note reports a predatory event of one Channel-billed Toucan upon eggs of Pale-breasted Thrush (Turdus leucomelas) and describes the anti-predatory behavior, principally alert and mobbing calls of the thrush. Even though the Pale-breasted Thrush displayed the anti-predatory behaviors to harass the toucan, the egg predation was not avoided. Although the predation upon eggs by Ramphastos vitellinus has been reported several times, the majority of reports lack the identity of the bird species affected, this being the first confirmed record in Turdus leucomelas.
RESUMEN El tucán de Ariel (Ramphastos vitellinus ariel) es un ave omnívora que eventualmente es ladrona de nidos. Varias aves paseriformes muestran estrategias anti-depredatorias, tales como ataques y llamadas de acoso para enfrentarse a este tipo de depredadores. Esta nota reporta un evento de depredación de un tucán de Ariel sobre huevos de la mirla pechi pálida (Turdus leucomelas), y describe el comportamiento antipredador, principalmente el relacionado con las llamadas de alerta y de acoso de la mirla. A pesar de que la mirla pechi pálida mostró un comportamiento anti-depredatorio acosando al tucán, no se evitó la depredación de los huevos. Aunque la depredación de huevos por parte del Ramphastos vitellinus se ha registrado varias veces, la mayoría de los reportes carecen de la identidad de la especie de ave afectada, siendo este el primer registro confirmado en Turdus leucomelas.
ABSTRACT
Abstract: Insect galls host a rich and diverse fauna of secondary dwellers, which compose the associated fauna. In Brazil, many inventories of insect galls in Cerrado areas have recorded secondary dwellers. These records were scattered in several papers. This study gathered literature data to provide an overview of the arthropod fauna associated with insect galls in the Brazilian Cerrado. We searched for scientific publications in online academic databases and retrieved 16 papers with data on the secondary dwellers. We limited our search to the period from 1988 to 2020. We updated the name of plant species and verified endemism and geographic distribution in Flora do Brasil 2020. We provided plant species uses based on the Tropical Useful Plants 2014. We found 163 gall morphotypes with secondary dwellers (16.8% of the total of gall morphotypes of the Brazilian Cerrado) on 94 plant species in 37 families. Asteraceae, Fabaceae, Myrtaceae, and Malpighiaceae exhibited the greatest number of records. These are the richest families in insect galls in the Brazilian Cerrado. Most arthropod fauna were recorded in galls of Cecidomyiidae (Diptera). Most records were in leaf galls, the predominant galled organ. Parasitoids were more frequent than successors, inquilines, and predators. Eulophidae and Eurytomidae were the most frequent parasitoid families. Inquilines were represented by Coleoptera, Diplopoda, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Psocoptera, and Thysanoptera; successors by Acari, Araneae, Cecidomyiidae (Diptera), Coleoptera, Collembola, and Formicidae (Hymenoptera), whereas predators by Pseudoscorpiones and Diptera. Most records were presented in suprageneric categories, showing that the taxonomic knowledge is very deficient. 29 plant species are endemic to Brazil and totaled 45 gall morphotypes with secondary dwellers; 46 plant species are useful and host secondary dwellers in 62 gall morphotypes. These data add ecological and economic importance to these arthropods.
Resumo: As galhas de insetos abrigam uma fauna rica e diversificada de habitantes secundários que compõem a fauna associada. No Brasil, muitos inventários de galhas de insetos em áreas de Cerrado registram habitantes secundários. Estes registros, dispersos em vários artigos, foram reunidos para fornecer uma visão ampla da fauna de artrópodes associados às galhas de insetos no Cerrado brasileiro. Buscamos publicações científicas nas bases de dados acadêmicas virtuais e encontramos 16 artigos com informações de habitantes secundários. Limitamos nossa busca ao período de 1988 a 2020. Atualizamos o nome das espécies botânicas e verificamos sua distribuição geográfica e endemismos no site Flora do Brasil 2020. Fornecemos os usos das espécies vegetais com base no site Tropical Useful Plants 2014. Encontramos 163 morfotipos de galhas com habitantes secundários (16,8% do total de morfotipos de galhas do Cerrado brasileiro) em 94 espécies de plantas de 37 famílias. Asteraceae, Fabaceae, Myrtaceae e Malpighiaceae exibiram o maior número de registros. Estas são as famílias mais ricas em galhas de insetos no Cerrado brasileiro. A maioria da fauna de artrópodes foi assinalada em galhas de Cecidomyiidae (Diptera). A maioria dos registros foi em galhas foliares, órgão vegetal com maior riqueza de galhas. Os parasitoides foram mais frequentes que os sucessores, inquilinos e predadores. Eulophidae e Eurytomidae foram as famílias de parasitoides mais frequentes. Os inquilinos foram representados por Coleoptera, Diplopoda, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Psocoptera, e Thysanoptera; os sucessores por Acari, Araneae, Cecidomyiidae (Diptera), Coleoptera, Collembola e Formicidae (Hymenoptera); enquanto os predadores por Pseudoscorpiones e Diptera. A maioria dos registros foi apresentada em categorias supragenéricas, mostrando que o conhecimento taxonômico é muito deficiente. Vinte e nove plantas são endêmicas do Brasil e totalizam 45 morfotipos de galhas com habitantes secundários; 46 espécies vegetais são úteis e hospedam habitantes secundários em 62 morfotipos de galhas. Estas informações acrescentam importância ecológica e econômica a estes artrópodes.
ABSTRACT
Abstract Impact of invasive species on native biota may be due to predation, competition for space or food, or indirect effects. Lionfish (Pterois volitans), invasive in the western Atlantic, is a voracious generalist predator, so it is expected to have a significant trophic overlap with native fishes of comparable size and habits. The goal of this study was to determine the diets of potential competitors of the lionfish, in particular a grouper, Cephalopholis cruentata (Graysby), and a snapper, Lutjanus apodus (Schoolmaster), and to compare them to the diet of lionfish in Xcalak, southern Mexican Caribbean. Stomach contents were analyzed and electivity and diet overlap were estimated. The trophic overlap between the lionfish and the two putative competitors, especially the grouper, was high, including prey that was consumed by the predators in higher proportion than the relative abundance of the prey in the environment, and probably at the same time of day. Lionfish and grouper shared as important diet items Stegastes sp., Halichoeres sp., Brachyura, and Palaemonidae, and most full stomachs were found during the early morning. The hypothesis of competition between them for particular prey is supported, so we advise to continue the culling programs of lionfish and also to monitor the abundance of the possible native competitors.
Resumo El impacto de las especies invasoras sobre la biota nativa puede deberse a depredación, competencia por espacio o alimento, o efectos indirectos. El pez león (Pterois volitans), invasor en el Atlántico occidental, es un voraz depredador generalista, de modo que se espera que tenga un notable sobrelape trófico con peces nativos de tamaño y hábitos comparables. El objetivo de este estudio fue determinar las dietas de competidores potenciales del pez león, en particular un mero, Cephalopholis cruentata (payaso), y un pargo, Lutjanus apodus (canchix), y compararlas con la dieta del pez león en Xcalak, sur del Caribe mexicano. Se analizaron los contenidos estomacales y se estimó la selectividad y el traslape de dietas. El traslape trófico entre el pez león y los dos posibles competidores, sobre todo el mero, fue amplio, incluidas presas consumidas por los depredadores en proporción mayor a la abundancia relativa de éstas en el ambiente, y probablemente a la misma hora del día. El león y el mero compartieron como presas importantes Stegastes sp., Halichoeres sp., Brachyura, y Palaemonidae, y la mayoría de los estómagos llenos se encontraron en horas tempranas de la mañana. Se apoya entonces la hipótesis de competencia entre ellos por presas específicas, de modo que recomendamos continuar el programa de extracción de pez león y también el monitoreo de la abundancia de los posibles competidores nativos.
ABSTRACT
ABSTRACT: The diversity of edaphic mites in Brazilian natural environments is little known, especially in the Pampa biome, in southern region of Brazil. The objective of this study was to evaluate the diversity and abundance of edaphic fauna of mesostigmatid mites in a region of the Pampa biome of the state of Rio Grande do Sul. Soil samples were collected in the municipality of Aceguá, in 2012 and 2013. Mites were extracted using Berlese-Tullgren modified funnels. In total, 1900 mesostigmatid mites were collected, representing 44 species from 23 genera and 10 families. The most abundant families were Rhodacaridae, Ologamasidae and Laelapidae, with respectively 903, 578 and 214 specimens, corresponding respectively to 47.5, 30.4 and 11.3% of the Mesostigmata collected. Laelapidae was the most diverse family, being represented by 22 species. The remaining families were each represented by 1-5 species. Gaeolaelaps (Laelapidae) was the most diverse genus, with 14 species. Rhodacaridae was represented by a single species, Binodacarus aceguaensis Duarte, Castilho, Cunha & Moraes, representing 47.5% of the mesostigmatids. Ologamasidae was represented by four species, with Neogamasellevans sp. corresponding to the second most abundant species, representing 27.5% of the mesostigmatids. Further analysis of the data, in terms of mite identification to species level and the potential use of the mites collected for applied biological control are needed.
RESUMO: A diversidade de ácaros edáficos em ambientes naturais brasileiros é pouco conhecida, especialmente no bioma Pampa na região sul do Brasil. O objetivo deste trabalho foi avaliar a diversidade e abundância da fauna edáfica de ácaros mesostigmatídeos no bioma Pampa, do sul do Brasil. Coletas de solo foram realizadas no município de Aceguá, em 2012 e 2013. Ácaros foram extraídos das amostras com o uso de funis de Berlese-Tullgren modificados. No total, 1900 ácaros mesostigmatídeos foram coletados, representando 44 espécies de 23 gêneros de 10 famílias. As famílias mais abundantes foram Rhodacaridae, Ologamasidae e Laelapidae, nesta ordem, com 903, 578 e 214 espécimes, correspondendo respectivamente a 47,5, 30,4 e 11,3% dos mesostigmatídeos coletados. Laelapidae foi a família mais diversa, sendo representada por 22 espécies. O restante das famílias foi representado por 1 - 5 espécies. Gaeolaelaps (Laelapidae) foi o gênero mais diverso, com 14 espécies. Rhodacaridae foi representada por uma única espécie, Binodacarus aceguaensis Duarte, Castilho, Cunha & Moraes, correspondendo a 47,5% dos mesostigmatídeos. Ologamasidae foi representado por quatro espécies, com Neogamasellevans sp. correspondendo a segunda espécie mais abundante, representando 27,5% dos mesostigmatídeos encontrados. Mais estudos são necessários para a identificação destes ácaros a nível de espécie, bem como para avaliar o potencial de uso destes no controle biológico aplicado.
ABSTRACT
Abstract Stress is conceptualized as a systemic response triggered by a stimulus potentially harmful to an organism. Instead of an adaptive outcome, life-threatening experiences may contribute to the development of anxiety disorders and depression. Predator scent stress (PSS) is one of the most utilized rodent models of stress-induced psychopathology, in which rodents are exposed to a volatile predator cue that signifies imminent danger. It is unclear if the duration of a life-threatening experience could have differential consequences on the expression of anxiety-like and depression-like behaviors. For this reason, the goal of this present study was to evaluate the effect of different exposure durations (3 min., 10 min., or 20 min.) to the scent of bobcat urine. Wistar rats housed under 12/12 dark cycle in standard laboratory conditions were exposed to the PSS model and 24 hrs. after the stressor, behavioral consequences were evaluated in the open field test, saccharin preference test, and forced swim test. The results obtained show that a 10-minute exposure is sufficient to induce an anxiety-like and a depression-like behavioral profile. We conclude that the time exposure could be a major variable to obtain clear and trustable results and to avoid overexposure to stressor.
Resumen El estrés es una respuesta sistémica desencadenada por un estímulo potencialmente peligroso para el organismo. Esta respuesta permite al organismo adaptarse a la condición estresante, sin embargo, experiencias que amenazan a la vida pueden incrementar el riesgo de desarrollar trastornos de ansiedad y depresión. La exposición al olor de depredador (EOD) es el modelo animal de patología inducida por estrés más utilizado. Consta de la exposición a una pista olfativa que significa peligro inminente. Aún no está claro si la duración a una experiencia que amenaza la vida puede generar diferencias en la expresión conductas tipo-ansiedad o tipo-depresión. Por esta razón, el objetivo de este estudio fue evaluar el efecto de diferentes duraciones de exposición (3 min., 10 min. o 20 min.) al aroma de lince. Se utilizaron ratas hembra de la cepa Wistar en un ciclo luz oscuridad 12/12 en condiciones estándar de laboratorio, los sujetos fueron evaluados en la prueba de campo abierto, preferencia de sacarina y nado forzado 24 hrs. después de terminado el estresor. Los resultados indican que la exposición a 10 min. es suficiente para inducir el perfil conductual tipo-depresión y tipo-ansiedad. Concluimos que el tiempo de exposición puede ser una variable de mayor importancia para obtener resultados confiables y prevenir exposiciones innecesarias al estrés.
ABSTRACT
Introduction: Cryphiops caementarius, is an endemic prawn from river ecosystems in Southern Perú and Northern Chile. In these watersheds, natural populations are threatened by multiple anthropic interventions such as mining activities and fishing pressure, but also, by increasing impacts of invasive exotic predators. Information related with predation on C. caementarius is scarce representing a major knowledge gap to ensure suitable management and conservation practices. Accordingly, the further deepening in relevant aspects such as the estimation of populations losses due to predators has been indicated as critical by relevant agencies as FAO. Objective: To conduct a complete registry and classification of C. caementarius predators, updating the knowledge for the Andean region. Methods: A thorough bibliographic review on existing information on C. caementarius' predators from Perú and Chile was carried out calculating percentage of occurrence, relative frequency of species, zoogeographic origin, trophic structure, phenotypic attributes, river zone that inhabits and life stage of incidence. The registry was complemented using semi-structured interviews from prawn´s fishers in central-Northern Chile. Results: C. caementarius is predated along the entire fluvial network (estuary, potamon and rhithron) by 21 species of opportunists, carnivores, omnivores and herbivores, mostly aquatic vertebrates. In turn, these belong to 15 families and six guilds of native, exotic and cosmopolitan species. Approximately 86 % predate on adult prawns, whilst, 71 % on juveniles and 24 % on larvae. More than 40 % of the predation pressure seems to be exerted by native waterfowls and 24 % by exotic fish. Conclusions: The results emphasize the relevance for conservation of native species of predators in the Andean region and the need of control measures on exotic species in a latitudinal basis. Accordingly, this review may serve as an initial decision-making tool for future conservation efforts both on prawns and native biota, but also supporting restocking actions, fisheries management plans and risk assessment for C. caementarius populations across the Andean region.
Introducción: Cryphiops caementarius es un camarón endémico de los ecosistemas fluviales del sur de Perú y norte de Chile. En estas cuencas hidrográficas, las poblaciones naturales están amenazadas por múltiples intervenciones antrópicas, como la actividad minera y presión pesquera, pero también por el creciente impacto de depredadores exóticos invasores. Información relacionada con la depredación sobre C. caementarius es escasa, representando una brecha de conocimiento importante para asegurar apropiadas prácticas de manejo y conservación. En consecuencia, la profundización en aspectos relevantes como la estimación de las pérdidas de población debido a los depredadores, ha sido indicada como crítica por agencias relevantes como FAO. Objetivo: Realizar un registro completo y clasificación de los depredadores de C. caementarius, actualizando el conocimiento para la región Andina. Métodos: Se realizó una revisión bibliográfica exhaustiva de la información existente sobre los depredadores de C. caementarius de Perú y Chile, calculando el porcentaje de frecuencia de ocurrencia y frecuencia relativa para cada especie, además de su respectivo origen zoogeográfico, estructura trófica, atributo fenotípico, zona fluvial que habita y etapa de la vida de incidencia del camarón. El registro se complementó con entrevistas semi-estructuradas a pescadores de camarones del centro-norte de Chile. Resultados: C. caementarius es depredado en diferentes zonas de la red fluvial (estuario, potamon y ritron) por 21 carnívoros, omnívoros y herbívoros, oportunistas y selectivos, en su mayoría vertebrados acuáticos. A su vez, estos se distribuyen en 15 familias y seis gremios, pertenecientes a tres categorías de origen zoogeográfico (nativo, exótico y cosmopolita). Aproximadamente el 86 % de estas especies depreda sobre la fracción adulta, mientras que el 71 % lo hace sobre juveniles y el 24 % sobre estadios larvales. Las aves acuáticas nativas ejercen más del 40 % de la presión depredadora, seguido por peces exóticos con un 24 %. Conclusiones: Los resultados enfatizan sobre relevancia que tiene la conservación de depredadores nativos en la región Andina y la necesidad de medidas de control sobre especies exóticas. En consecuencia, esta revisión puede servir como una herramienta inicial de toma de decisiones para futuros esfuerzos de conservación tanto de camarones como de la biota nativa, pero también apoyando acciones de gestión pesquera y evaluación de riesgos para C. caementarius en toda la región Andina.
ABSTRACT
Los estudios sobre percepción humana hacia depredadores, generalmente se realizan con adultos. Sin embargo, es importante entender las percepciones de los niños, para diseñar estrategias de conservación y educación ambiental efectivas a largo plazo, ya que muchos de ellos serán los futuros manejadores de los recursos naturales. Analizamos las percepciones sobre el jaguar en niños de 8-12 años (n = 89) en comunidades dentro de la Reserva de la Biosfera Sierra de Manantlán (RBSM) y en su zona de influencia (ZI). Para conocer la percepción del jaguar, organizamos talleres con los niños, guiándolos con preguntas abiertas que respondieron con dibujos: ¿Qué animales viven en el monte/bosque? ¿Qué animales peligrosos viven en el monte/bosque? ¿Cómo es el jaguar y qué come? En todas las preguntas se especificó que nos referíamos a los animales presentes en los alrededores de su comunidad. Aparentemente el miedo colectivo hacia los animales influye en que animales se perciben en el entorno, ya que casi nadie dibujó al jaguar como parte del paisaje, pero si como animal peligroso. Las serpientes fueron las que más se relacionan como parte del entorno, y a la vez fueron las que más se mencionaron como animales peligrosos en ambas zonas. En el dibujo de animales peligrosos, hubo 72 menciones de animales no nativos. En ambas áreas, poco más de la mitad de los niños reconoce la forma básica del jaguar. Sobre todo, en la RBSM, la mayoría dibujó ganado vacuno en la dieta del jaguar, representando uno de los conflictos jaguar-humanos. Casi la mitad de los niños dibujó a los venados como parte de la dieta del jaguar en la RBSM y un tercio en la ZI. Un número considerable de niños incluyeron humanos en la dieta en ambas zonas. Concluimos que con el fin de mejorar la percepción es deseable desarrollar estrategias para cambiar las percepciones negativas del jaguar. Por ende, es importante generar material educativo y llevar a cabo campañas de educación ambiental resaltando la importancia ecológica del jaguar, enfatizando que el buen manejo del ganado reduce la depredación y que los humanos no son elementos de la dieta del jaguar. En resumen, es importante generar mayor empatía con el jaguar, y aclarar creencias erradas que puedan afectar la supervivencia del jaguar a largo plazo en estas áreas.
Predator perception studies generally only regard adults. However, it is necessary to also understand children perceptions in order to achieve more effective long term conservation and environmental educational strategies, since many of them will be the future resource managers. We analyze perceptions of the jaguar amongst children (n = 89) between 8 and 12 years old, in the Sierra de Manantlán Biosphere Reserve (SMBR) and its influence zone (ZI). To understand their perceptions, we organized workshops, using open-ended questions, to be answered with drawings: What animals live in the forest? Which dangerous animals live in the forest? What do jaguars look like and what do they eat? In all questions, we specified that we referred to animals close to their community. Apparently collective apprehension influences, which animals are perceived as part of the environment. Our results suggest that the jaguar is not conceived as part of the (direct) environment, but is conceived as dangerous animal in the area. Snakes are most mentioned as part of the environment; at the same time, they are perceived as the most dangerous. In the dangerous animal drawings, there were 72 mentions of no native animals. In all cases, more than half of the children knew the basic shape of a jaguar. Overall in the SMBR, most children drew cattle as the main food staple for the jaguar, representing one of the human-jaguar conflicts. Half of children drew deer as jaguar diet in the SMBR and one third in the ZI. A considerable number of children included humans in the jaguar diet in both zones. We conclude that it is necessary to develop strategies to change the negative perceptions of the jaguar. As such, it is important to generate educational material and carry out educational campaigns that highlight the ecological importance of the jaguar, and emphasizing those livestock management actions to reduce predation and the disappearance of false beliefs; which include jaguar as a people eater. In summary, is important to generate greater empathy with the jaguar, and clarify misconceptions that may affect the long-term survival of the jaguar in these areas.
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ABSTRACT: Blackberry is part of the small-fruit group and the blackberry cultivation area is expanding as an important option for small farmers using the agroecological production system. Mites are prominent among the world's major crop pests, as they can affect plants from growth to fruiting. The objective of this study was to evaluate the occurrence of phytophagous and predatory mites in different blackberry genotypes in the municipality of Pelotas, RS, Brazil. This study was carried out in the period Nov. 2015 - Oct. 2016, totaling 14 samples. A total of 11,158 mites were collected [phytophagous (5940) and predatory (323) mites, and those with varied feeding habits (4895)], which were distributed in 8 families. The species Neotetranychus asper (Feres & Flechtmann, 2000), Diptacus rubuscolum (Trinidad, Duarte & Navia, 2018), and Acalitus orthomerus (Keifer, 1951) had highest occurrence. According to the faunistic classification, the N. asper phytophagous species is predominant in genotypes 128 and 178; whereas, D. rubuscolum is predominant in genotype 132. Monitoring of these genotypes is recommended to detect possible damage to the crop.
RESUMO: A amoreira-preta faz parte do grupo das pequenas frutas e sua área de cultivo está em plena expansão, sendo uma opção importante para os pequenos agricultores que usam o sistema de produção agroecológico. Os ácaros destacam-se dentre as principais pragas da cultura em nível mundial, pois eles podem comprometer desde o crescimento das plantas até sua frutificação. O objetivo desta pesquisa foi estudar a ocorrência de ácaros fitófagos e predadores em diferentes genótipos de amoreira preta no município de Pelotas, RS, Brasil. Este estudo foi realizado no período novembro de 2015 a outubro de 2016, totalizando 14 amostragens. Um total de 11.158 ácaros coletou-se (5.940 ácaros fitófagos, 323 ácaros predadores, e 4.895 ácaros de alimentação variada), que estavam distribuídos em oito famílias. As espécies Neotetranychus asper (Feres & Flechtmann, 2000), Diptacus rubuscolum (Trinidad, Duarte & Navia, 2018), e Acalitus orthomerus (Keifer, 1951) tiveram maior ocorrência. De acordo com a classificação faunística, a espécie fitófaga N. asper é predominante nos genótipos 128 e 178, enquanto a espécie D. rubuscolum é predominante no genótipo 132. Monitorar esses genótipos é recomendado para detectar possíveis danos à cultura.
ABSTRACT
Abstract Antlion larvae Myrmeleon brasiliensis Návas, 1914 (Neuroptera, Myrmeleontidae) are sit-and-wait predators who build traps to catch their prey. The aim of this study was to observe under laboratory conditions, how the energy cost spent on maintenance of their traps affects: the larval developmental time, time spent as a pupa, mortality rate of larvae and adult size. M. brasiliensis larvae were collected in the municipality of Aquidauana, Mato Grosso do Sul, Brazil and were individually maintained in plastic containers and subjected to two treatments. In the control treatment larvae did not have their traps disturbed while in the manipulated treatment, larvae had their traps disturbed three times a week. The experiments were followed until adult emergence. When the adults emerged, their body size (head-abdomen), anterior and posterior wing span and width were measured. Furthermore, the number of larvae that died during the experiment was recorded. The results showed that the larvae whose traps were manipulated had longer larval development time, smaller pupal development time and were smaller adults. It can be concluded that the energy expenditure spent on maintenance of the trap constructed by M. brasiliensis larvae can affect the development of negative ways, represented by a longer larval development and reduced adult size.
Resumo Efeito do custo energético com a manutenção da armadilha de Myrmeleon brasiliensis no seu desenvolvimento e no tamanho dos adultos. Larvas de formiga-leão Myrmeleon brasiliensis são predadores senta-espera que constroem armadilhas para a captura de suas presas. O objetivo deste trabalho foi observar em laboratório, como o gasto energético despendido com a manutenção dessas armadilhas afeta: o tempo de desenvolvimento larval, o tempo de pupa, a taxa de mortalidade das larvas e o tamanho dos adultos. M. brasilienses foram coletadas no município de Aquidauana, Mato Grosso do Sul, então foram individualizadas em potes plásticos e submetidas a dois tratamentos. No tratamento controle, as larvas não tiveram suas armadilhas perturbadas e no tratamento manipulado, as larvas tiveram as suas armadilhas perturbadas três vezes por semana. Os experimentos foram acompanhados até a emergência dos adultos. Quando esses emergiam, era medido o seu tamanho corporal (cabeça-abdômen), envergadura da asa anterior e posterior e largura da asa anterior e posterior. Além disso, foi contabilizado o número de larvas mortas no decorrer dos experimentos. Como resultado foi observado que as larvas manipuladas apresentaram o tempo de desenvolvimento larval maior, o tempo de pupa menor e o tamanho dos adultos foi menor. Pode-se concluir que o gasto energético despendido com a manutenção da armadilha construída pelas larvas M. brasiliensis pode afetar o seu desenvolvimento de maneiras negativas, representados pelo maior tempo de desenvolvimento larval e menor tamanho do adulto.
Subject(s)
Animals , Insecta/growth & development , Pupa , Body Size , Energy Metabolism , Larva/growth & developmentABSTRACT
ABSTRACT The species richness and relative abundances of different aboveground plant-dwelling pest and predator species were assessed in flax (Linum usitatissimum L.) ecosystem under mid-hill conditions of eastern Himalayas. The experiment was conducted in winter seasons during 2004-2013 at the Regional Research Station (Hill Zone), Uttar Banga Krishi Viswavidyalaya, Kalimpong, West Bengal, India. Twenty five species of phytophagous arthropods under 13 families were observed belonging to 6 different orders. The gram pod borer, Helicoverpa armigera (Noctuidae: Lepidoptera), aphid, Myzus persicae (Aphididae: Hemiptera), shield bug, Plautia fimbriata (Pentatomidae: Hemiptera) and leaf webber, Nacoleia sp. (Pyralidae: Lepidoptera) were found as the most common and major insect of flax. In terms of species composition, Hemiptera and Lepidoptera occupied top position (nine species) while Coleoptera ranked second position (five species). By the size of population, aphid was found to be the most frequent species followed by shield bug and leaf webber. Although, the incidence of gram pod borer was low in the field, it was the major pest of flax in respect of bud and capsule damage. The Gini-Simpson index and Effective number of species for the pest faunal complex of flax was calculated as 0.914 and 11.628, respectively. Similarly, 16 species of predatory arthropods under nine families were observed belonging to 7 different orders. The lynx spider (17.24 %) and 7-spotted lady beetle (15.52 %) dominated the predatory community by sheer number. The Gini-Simpson index and Effective number of species for the predatory fauna was derived as 0.898 and 9.804, respectively.
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AbstractThis study aimed to test for vertical stratification and the effects of dry leaf size on herbivore and predator arthropods and petiole length on insect borers in Cecropia pachystachya. The leaves were sampled in three strata: attached to the plant, suspended on the vegetation and on the ground. We detected vertical stratification only in the guild of predator arthropods associated with dry leaves, with lower richness and abundance in the attached stratum. In addition, larger leaves positively affected the insect herbivore fauna, whereas the richness and abundance of insect borers increased with petiole length. The greater isolation of leaves attached to trees relative to the surrounding vegetation likely creates greater difficulty for dispersal and colonization by non-winged predators such as spiders. Larger dry leaves provide more shelter against predators and climate variations for insect herbivores. Moreover, larger petioles increase the availability of resources and nesting sites for insect borers. These results are consistent with other studies that found a similarity in the structure of feeding guilds across vertical strata and with studies that showed an increase in species richness and abundance of free-feeding insect herbivores with increasing structural complexity of their host.
ResumoOs objetivos do presente trabalho foram testar as hipóteses de que existe estratificação vertical e efeito do tamanho de folhas secas de Cecropia pachystachya sobre artrópodes herbívoros e predadores, e efeito do tamanho dos pecíolos sobre insetos brocadores. As folhas foram amostradas em três estratos: presas à planta, caídas sobre a vegetação e no solo. Foi verificada estratificação vertical apenas para os artrópodes predadores, com menor riqueza e abundância no estrato presa. Além disso, folhas maiores afetam positivamente a fauna de insetos herbívoros, enquanto que a riqueza e abundância de brocadores aumentam com o tamanho do pecíolo. O maior isolamento das folhas presas em relação à vegetação do entorno provavelmente determina maior dificuldade de dispersão e colonização por predadores não alados, como aranhas. Folhas secas maiores oferecem maiores áreas de refúgio e abrigo contra predadores e variações climáticas para insetos herbívoros. Além disso, maiores pecíolos aumentam a disponibilidade de alimento e locais para nidificação dos insetos brocadores. Estes resultados são consistentes com estudos que encontraram uma similaridade na estrutura de guildas alimentares entre estratos verticais. Corroboram também estudos que mostram o aumento da riqueza e abundância de insetos herbívoros de vida livre com o aumento da complexidade estrutural do hospedeiro.
Subject(s)
Animals , Arthropods/physiology , Biodiversity , Food Chain , Plant Leaves/physiology , Urticaceae/physiology , Brazil , Herbivory , Predatory Behavior , SoilABSTRACT
This research aimed to investigate the diversity of species of lacewings (Chrysopidae) associated to trellised tomato crops in the counties of Cambuci and Seropédica, in Rio de Janeiro State, Brazil. Eggs and adults of chrysopids were collected, manually and by oral suction device, respectively, in Cambuci (commercial farming) and Seropédica (experimental farming). Four species were obtained: Ceraeochrysa cincta (Schneider, 1851), Ceraeochrysa sp1., Chrysopodes elongatus (Freitas; Penny, 2001) and Chrysopodes sp1. in the experimental farming in Seropédica, while in the commercial farming in Cambuci only two species were found: Chrysoperla externa (Hagen, 1861) and Ceraeochrysa cubana (Hagen, 1861).(AU)
Objetivou-se, com a presente pesquisa, conhecer a diversidade de espécies de crisopídeos (Chrysopidae) em cultivos de tomateiro estaqueado localizados nos municípios de Cambuci e Seropédica, no Rio de Janeiro, Brasil. Ovos de crisopídeos foram coletados manualmente, e os adultos do predador, com o uso de aspirador bucal em lavoura comercial, em Cambuci, e em lavoura experimental, em Seropédica. Em Seropédica foram obtidas quatro espécies de crisopídeos: Ceraeochrysa cincta (Schneider, 1851), Ceraeochrysa sp1., Chrysopodes elongatus (Freitas; Penny, 2001) e Chrysopodes sp1. e em Cambuci, duas espécies: Chrysoperla externa (Hagen, 1861) e Ceraeochrysa cubana (Hagen, 1861).(AU)
Subject(s)
Pest Control, Biological , Solanum lycopersicum , InsectaABSTRACT
O objetivo foi estudar a seletividade de inseticidas aos inimigos naturais na cultura do algodão (Gossypium hirsutum L.r. latifolium Hurtch), cultivar DeltaOpal, no município de Malhada (BA) e conhecer a fauna benéfica associada. O trabalho foi conduzido na safra 2010/2011, com delineamento experimental em blocos ao acaso, com seis tratamentos e quatro repetições, sendo os tratamentos: (1) Fipronil 200 SC (0,38 L.ha-1); (2) Alfacipermetrina 100 SC (0,30 L.ha-1); (3) Lufenuron 50 CE (0,30 L.ha-1); (4) Imidacloprid 200 SC (0,30 L.ha-1); (5) Paration Metil 600 CE (1,00 L.ha-1); e (6) Testemunha (água). A aplicação dos produtos foi feita 80 dias após a emergência, com avaliações um dia antes da aplicação e 1, 7 e 14 dias após a aplicação (DAA) por meio do pano de batida e armadilha Moericke. Em laboratório, os insetos foram triados, contados e identificados em famílias. A toxicidade dos produtos varia em função do grupo do inimigo natural. A Imidacloprida é seletiva às aranhas, sendo os demais inseticidas medianamente tóxicos (Alfacipermetrina e Paration Metil: 1º e 14º DAA; Lufenuron: 14º DAA) ou tóxicos (Fipronil e Alfacipermetrina: 7º DAA). Fipronil (1º DAA), Alfacipermetrina (7º DAA) e Paration Metil (14º DAA) são medianamente tóxicos aos adultos de joaninhas. Os inseticidas estudados são tóxicos às larvas de joaninhas, com mais impacto até os sete dias após a aplicação, com exceção do Paration Metil, classificado como inócuo até esse período. Registra-se a ocorrência de 13 famílias de aranhas e 18 famílias de hymenópteros parasitoides em agroecossistema de algodão na região de Malhada (BA).(AU)
The aim of this work was study the selectivity of insecticides in favor of natural enemies in cotton (Gossypium hirsutum latifolium Hurtch Lr), DeltaOpal cultivar, in the city of Malhada (BA), and to know the associated beneficial fauna. The study was conducted at the agricultural year of 2010/2011. The design was conducted in randomized blocks with six treatments and four replications. The treatments were: (1) Fipronil 200 SC (0.38 L.ha-1); (2) Alphacypermethrin 100 SC (0.30 L.ha-1), (3) Lufenuron 50 EC (0.30 L.ha-1), (4) Imidacloprid 200 SC (0.30 L.ha-1), (5) Methyl parathion 600 EC (1.00 L.ha-1), and (6) control (water). The product was applied 80 days after emergence, and the evaluations were performed one day before application and 1, 7 and 14 days after application (DAA). The samples were taken using the sampling method beating cloth and Moericke traps. Natural enemies were brought to the laboratory for sorting, counting and identification by family. The toxicity of the products ranged according to the group of natural enemies. Imidacloprid is selective to the spiders and insecticides are moderately toxic (Methyl Parathion and Alphacypermethrin: 1 and 14th DAA; Lufenuron: 14th DAA) or toxic (Fipronil and Alphacypermethrin: 7thDAA). Fipronil (1 DAA), Alphacypermethrin (7th DAA) and Methyl Parathion (14th DAA) are moderately toxic to adult ladybirds. The analyzed insecticides are toxic to the larvae of ladybirds, with more impact until seven days after the application, with the exception of Methyl Parathion classified, as innocuous until this period. The occurrence of 13 families of spiders and 18 families of parasitic Hymenoptera is registered in cotton agroecosystems in the region of Malhada, in the state of Bahia.(AU)
Subject(s)
Gossypium , Insecticides/toxicity , Pest Control , Pest Control, BiologicalABSTRACT
Fruits of trumpet tree (Cecropia spp.) attract different species of birds and mammals. Boas (Boa constrictor) are sit-and-wait strategists, able to choose to ambush in microhabitats that are frequently visited by prey. We have seen two events of predation of passerines (Pitangus sulphuratus, Turdus rufiventris) by boas on the same trumpet tree (Cecropia pachystachya) in a remnant of Cerrado, in the city of Campo Grande/MS. These reports may be evidence of strategic association of boas to trumpet trees, considering the density of snakes recorded on the tree and the constant visits by potential prey during fruiting periods. Besides encouraging a more detailed investigation on the strategies of predation by boas, our records constitute relevant information about the snake natural history.
Frutos de embaúba (Cecropia spp.) atraem diversas espécies de aves e mamíferos. Jiboias (Boa constrictor) são estrategistas senta-espera, capazes de selecionar micro-habitats que são frequentemente visitados por presas. Nós presenciamos dois eventos de predação de passeriformes (Pitangus sulphuratus, Turdus rufiventris) por jiboias sobre uma mesma embaúba (Cecropia pachystachya) em um remanescente de Cerrado, localizado na cidade de Campo Grande/MS. Esses relatos podem ser indícios de associações estratégicas das jiboias ès embaúbas, considerando a densidade de serpentes na árvore e a constante visitação de presas potenciais durante os períodos de frutificação. Além de estimular uma investigação mais detalhada sobre as estratégias de predação das jiboias, esses registros constituem informações relevantes sobre sua história natural.
ABSTRACT
This study reveals the food composition of pelagic fishes living in the southwestern Atlantic Ocean. As such more common pelagic species are considered to be top predators, the study proposes to know what constitutes their main food. Fish are not commonly found within their stomach contents, but instead, cephalopods are their most common food. As can be observed, Teuthida cephalopods compose their principal diet. The stomach contents of specimens of Xiphias gladius, Thunnus albacares, T. obesus, T. alalunga, Isurus oxyrinchus and Alopias superciliosus caught during July 2007 to June 2009 by using tuna longliners were studied. Teuthida cephalopods constitute the main food item for the three tuna species, while X. gladius feeds mainly on Ommastrephidae cephalopods. Though the differences among the kinds of cephalopods exist, they constitute the principal resource these fish use to live at least in the southern Atlantic Ocean.
Este estudo descreve a composição da dieta de peixes pelágicos que vivem no Oceano Atlântico Sudoeste. Como tais espécies pelágicas são consideradas predadoras de topo, o estudo propõe conhecer o que constitui sua principal fonte de alimento. Peixes não são comumente encontrados em seus conteúdos estomacais, em vez disso, os cefalópodes são os alimentos mais comuns. Como pode ser observado, cefalópodes Teuthida compreendem sua dieta principal. O conteúdo estomacal de espécimes de Xiphias gladius, Thunnus albacares, T. obesus, T. alalunga, Isurus oxyrinchus e Alopias superciliosus, capturados durante julho de 2007 a junho de 2009 prela frota atuneira, foram estudados. Cefalópodes Teuthida constituem o principal item alimentar das três espécies de atum, enquanto X. gladius alimenta-se principalmente de cefalópodes Ommastrephidae. Embora as diferenças entre os tipos de cafalópodes existam, eles constituem o principal recurso que estes peixes usam para viver, pelo menos no Oceano Atlântico Sudoeste.
ABSTRACT
Fishes at Isla del Coco National Park, Costa Rica, were surveyed as part of a larger scientific expedition to the area in September 2009. The average total biomass of nearshore fishes was 7.8 tonnes per ha, among the largest observed in the tropics, with apex predators such as sharks, jacks, and groupers accounting for nearly 40% of the total biomass. The abundance of reef and pelagic sharks, particularly large aggregations of threatened species such as the scalloped hammerhead shark (up to 42 hammerheads ha-1) and large schools of jacks and snappers show the capacity for high biomass in unfished ecosystems in the Eastern Tropical Pacific. However, the abundance of hammerhead and reef whitetip sharks appears to have been declining since the late 1990s, and likely causes may include increasing fishing pressure on sharks in the region and illegal fishing inside the Park. One Galapagos shark tagged on September 20, 2009 in the Isla del Coco National Park moved 255km southeast towards Malpelo Island in Colombia, when it stopped transmitting. These results contribute to the evidence that sharks conduct large-scale movements between marine protected areas (Isla del Coco, Malpelo, Galápagos) in the Eastern tropical Pacific and emphasize the need for regional-scale management. More than half of the species and 90% of the individuals observed were endemic to the tropical eastern Pacific. These high biomass and endemicity values highlight the uniqueness of the fish assemblage at Isla del Coco and its importance as a global biodiversity hotspot.
La biomasa promedio de peces costeros en el Parque Nacional Isla del Coco en septiembre de 2010 fue de 7,8 toneladas por hectárea, entre las más elevadas halladas jamás en zonas tropicales. Los grandes depredadores representaron el 40% de la biomasa total. La abundancia de tiburones costeros y pelágicos, particularmente las enormes agregaciones de tiburón martillo (hasta 42 individuos por hectárea) y los extensos bancos de carángidos y lutjánidos, muestran la capacidad que tienen los ecosistemas marinos no pescados para albergar elevadas biomasas de peces, y hacen de la Isla del Coco un lugar único en el mundo. No obstante, la abundancia de tiburones parece estar decreciendo desde 1999, probablemente a causa de la creciente presión pesquera en la región y la pesca ilegal en el interior del Parque. Un tiburón de Galápagos marcado se dirigió 255km en dirección a la Isla de Malpelo, Colombia. Estos resultados sugieren que los tiburones realizan importantes movimientos entre áreas marinas protegidas (Isla del Coco, Malpelo, Galápagos) en el Pacífico Tropical Oriental y remarcan la necesidad de una gestión regional de estos animales. Más del 50% de las especies y el 90% de individuos observados en los contajes eran endémicos del Pacífico Tropical Oriental.