Comparación ecotoxicológica al Cloruro de Sodio en Hydra vulgaris e Hydra viridissima

El aumento de la salinidad en los ecosistemas de agua dulce genera preocupación sobre los efectos adversos que puede provocar sobre las especies dulceacuícolas y el suelo. Las concentraciones óptimas de iones de sodio y calcio para que las especies del género Hydra tengan condiciones fisiológicas adecuadas son relativamente bajas. Este trabajo se enfocó en comparar la sensibilidad de H. vulgaris e H. viridissima frente al cloruro de sodio (NaCl). Las especies fueron mantenidas bajo condiciones de fotoperiodo, iluminación y temperatura controladas. Se obtuvieron las tasas de crecimiento y en ensayos de toxicidad aguda se calcularon las CE50 (Concentración efectiva media) y CL50 (Concentración letal media) como indicadores de la sensibilidad al NaCl. H. vulgaris fue más sensible al NaCl dado que la CL50-96h fue de 1,0 g/l NaCl (entre 0,8 - 1,2 g/l como intervalo de confianza al 95%), mientras que H. viridissima presentó una CL50-96h promedio de 2,6 g/l (entre 2,0 - 3,3 g/l como intervalo de confianza del 95%). Se considera que esta última fue más tolerante al NaCl, probablemente por la relación simbiótica con la microalga Chlorella vulgaris, ya que podría generar un efecto protector. Se espera que comprender el comportamiento de estos biomodelos respecto al aumento de la salinización permita la evaluación temprana de riesgos ecológicos en ecosistemas acuáticos tropicales.

The increase in salinity in freshwater ecosystems raises concern about the adverse effects that it can cause in freshwater species and the soil. The sodium and calcium ions optimum concentrations required for genus Hydra to have adequate physiological conditions are relatively low. This research compared the H. vulgaris and H. viridissima sodium chloride (NaCl) sensitivity. The species were propagated under photoperiod, lighting and temperature-controlled conditions. The growth rates were obtained and EC50 (mean effective concentration) and LC50 (mean lethal concentration) were calculated by means of acute toxicity tests as indicators of sensitivity to NaCl. For H. vulgaris the LC50-96h was 1.0 g/l of NaCl with a range between 0.8 - 1.2 g/l of NaCl, compared to H. viridissima presented an average LC50-96h of 2.6 g/l of NaCl with a 95% confidence interval between 2.0 - 3.3 g/l of NaCl. The H. viridissima was more tolerant, probably the symbiotic relationship with Chlorella vulgaris, can generate a protective effect. Understanding the behavior of these species with respect to increased salinization can allow an early assessment of ecological risks in tropical aquatic ecosystems.

Ecological and biological patterns of stream fish studies from the Piracicaba-CapivariJundiaí Basin (PCJ Basin, SP) assessed through a systematic review / Padrões ecológicos e biológicos de estudos de peixes de riachos da Bacia PiracicabaCapivari-Jundiaí (Bacia PCJ, SP) avaliados por meio de uma revisão sistemática

Tropical streams are among the most threatened ecosystems in the world. As such, studies carried out and compiled over spatial and temporal scales can provide useful information to examine patterns of species diversity and threats to their survival. Here we conducted a systematic review of published research on biological and ecological aspects of stream fish fauna found in the Piracicaba-Capivari-Jundiaí Basin, an industrial watershed of São Paulo State. We aimed to detect main patterns, trends and gaps in studies related to species composition, distribution, spatial and temporal scales, as well as in the covered topics. Results were related to main land uses, biomes and Conservation Units. A constant increase in published articles occurred from 2003 until 2016 with an average of 1.8 articles/year. Twenty-six publications were considered for the present study, reporting on fish samples obtained in 67 sites and resulting in 89 species. A high proportion of studies were concentrated in the Corumbataí sub-basin, and rarefaction curves indicated that stream fish richness in the PCJ Basin may be considerably higher than that shown by the actual numbers. Basin studies were unevenly distributed and did do not include such highly preserved areas as the Camanducaia, Jaguari and Jundiaí sub-basins. We emphasize the importance of further surveys in these regions, as well as in high priority conservation areas, which may lead to new insights for developing appropriate conservation strategies for this basin.

Riachos tropicais estão entre os ecossistemas mais ameaçados do mundo e a compilação de estudos temporais e espaciais pode fornecer informações úteis para examinar padrões de diversidade de espécies e ameaças nesses sistemas. Realizamos uma revisão sistemática das pesquisas publicadas sobre aspectos biológicos e ecológicos da ictiofauna de riachos da bacia do Piracicaba-Capivari-Jundiaí, uma bacia industrial do Estado de São Paulo. O objetivo foi detectar os principais padrões, tendências e lacunas em estudos relacionados à composição, distribuição de espécies, escalas espaciais, temporais e temas abordados. Os resultados foram relacionados aos principais usos do solo, biomas e Unidades de Conservação. Foi verificado um aumento constante de artigos entre 2003 e 2016, com média de 1,8 artigos/ano. Vinte e seis publicações foram consideradas para o estudo, que indicaram 67 locais amostrados, e o registro de 89 espécies. Uma alta proporção deles concentrou-se na sub-bacia de Corumbataí e curvas de rarefação indicaram que a riqueza de peixes de riacho na bacia do PCJ deve ser consideravelmente maior do que os números atuais. A distribuição desigual de estudos na bacia, que não inclui áreas altamente preservadas como as sub-bacias de Camanducaia, Jaguari e Jundiaí, enfatiza a necessidade de se obter mais informações nessas regiões, bem como em áreas de conservação de alta prioridade. Novas abordagens relacionadas a conceitos e teorias ecológicas em estudos futuros poderão fornecer informações que ajudem a desenvolver estratégias de conservação adequadas para esta bacia.

The introduction of Physa acuta (Gastropoda: Physidae) on Ilha Grande, Southeast Brazil, from initial stages to an established population / A introdução de Physa acuta Draparnaud, 1805 (Gastropoda: Physidae) na Ilha Grande, Sudeste do Brasil, desde os estágios iniciais até uma população estabelecida

Abstract This study presents a four-year follow-up of an introduced population of Physa acuta Draparnaud, 1805, from initial stages to an established population. This introduction occurred on a small impacted stream of Vila do Abraão, the main village of Ilha Grande (Angra dos Reis, Rio de Janeiro, Brazil). The population size increased during the study, and presented a relationship to environmental factors, especially with rainfall. On the initial stages of introduction prevailed the smaller specimens, but on the overall, predominated the intermediate size classes. After less than a year, P. acuta becomes established on this stream and was possibly affecting the other species found on the stream. The information presented here is useful to understand the invasion process of invasive snails, as well as directing conservation efforts.

Resumo Neste estudo é apresentado um acompanhamento de quatro anos de uma população de Physa acuta Draparnaud, 1805, desde os estágios iniciais da introdução até seu pleno estabelecimento. Esta introdução ocorreu em um pequeno riacho impactado da Vila do Abraão, o principal vilarejo da Ilha Grande (Angra dos Reis, Rio de Janeiro, Brasil). A população cresceu durante o estudo, e apresentou uma relação com os fatores ambientais, especialmente a pluviosidade. Nos estágios iniciais de introdução prevaleceram os exemplares menores, contudo no panorama geral, predominaram as classes de tamanho intermediárias. Em menos de um ano de introdução, P. acuta se estabeleceu neste riacho, e possivelmente está afetando as demais espécies encontradas no rio. A informação apresentada aqui é importante para a compreensão do processo de invasão de moluscos invasores no Brasil, assim como no direcionamento de esforços de conservação.

Length-weight relationships of 24 stream-dwelling fish species from the Atlantic Forest in Rio de Janeiro, Brazil / Relação peso-comprimento de 24 espécies de peixes de riachos da Mata Atlântica do Rio de Janeiro, Brasil

Abstract The length-weight relationship parameter is important for obtaining fish weight and biomass data with relevant implications about species role on ecosystem functioning. Here we report the length-weight relationship (LWR) for 24 fish species from three streams located in the Atlantic Forest in the Rio de Janeiro State, Brazil. Fish were collected with electrofishing and standard length (cm) and wet weight (g) were measured to obtain the a and b parameters of the Log (W) = Log (a) + b Log (SL) equation. Length-weight relationships for seven out of 24 species (Hypostomus punctatus, Deuterodon taeniatus, Deuterodon hastatus, Deutorodon janeiroensis, Characidium vidali, Characidium interruptum and Rineloricaria zawadiskii) are reported for the first time. The length-weight relationships reported here contribute to the database that can support fish diversity conservation, fisheries management plans and studies on fish biology.

Resumo A relação peso-comprimento é um parâmetro importante para se obter o peso do peixe e sua biomassa, fornecendo dados importantes a serem incorporados em estudos sobre o papel das espécies em processos ecossistêmicos. Aqui, reportamos as relações peso-comprimento de 24 espécies de peixes de três rios localizados na Mata Atlântica do estado do Rio de Janeiro, Brasil. Os peixes foram coletados com a pesca elétrica e seu comprimento padrão (cm) e peso (g) foram medidos para obter os parâmetros a e b da equação Log(P) = Log (a) + b Log (CP). As relações peso-comprimento de sete entre as 24 espécies (Hypostomus punctatus, Deuterodon taeniatus, Deuterodon hastatus, Deutorodon janeiroensis, Characidium vidali, Characidium interruptum e Rineloricaria zawadiskii) são reportados pela primeira vez. As relações peso-comprimento informadas contribuem para a base de dados que auxilia na conservação da diversidade de peixes, na preparação de planos de manejo de pesca e estudos da biologia de peixes.

EphemBrazil: a curated online database and dashboard to explore the distribution of mayflies (Insecta: Ephemeroptera) from Brazil

ABSTRACT Despite the growing number of studies on mayflies (Ephemeroptera), especially in terms of description of new species and distributional records, the knowledge generated remains scattered across specialized literature. This dispersion poses a challenge for non-specialists, such as ecologists, hindering their ability to promote studies and conservation actions. In order to fill this gap, we are launching EphemBrazil: an online database focusing on the distribution of mayflies in Brazil. The main objectives of this platform are to compile a dataset of distributional information for the valid species of Ephemeroptera in Brazil, provide open access to this dataset through an interactive and easily updated website, and offer dynamic distributional maps for species, genera, and families of Brazilian mayflies. EphemBrazil aims to facilitate the retrieval and access of distributional and basic taxonomic information for the order.

Considering the role of the assassin snail Anentome helena as a biological control of Bithynia siamensis goniomphalos, the first intermediate host of Opisthorchis viverrini

This study aims to investigate whether the assassin snail Anentome helena may serve as a biological control agent of Bithynia siamensis goniomphalos, the 1st intermediate host of Opisthorchis viverrini. Experiments were carried out in the laboratory, and the results found that A. helena showed the variation and selection of mollusc prey. A. helena can consume B. siamensis goniomphalos, which is remarkable because this snail can compete with other snails and could be used as a biological control. The consumption rate of the predator was compared, and it was found that A. helena prefers to consume Indoplanorbis exustus, followed by Pomacea canaliculata, Melanoides tuberculata, Filopaludina sumatrensis speciosa, Lymnaea sp., and B. siamensis goniomphalos. This is the first report of an experimental study controlling B. siamensis goniomphalos using A. helena. Our data imply that A. helena can control the B. siamensis goniomphalos population with good results, especially in the absence of other snail species.

An updated distribution list of Leptophlebiidae Banks, 1900 (Ephemeroptera: Insecta) for Piauí state / Uma lista de distribuição atualizada de Leptophlebiidae Banks, 1900 (Ephemeroptera: Insecta) para o estado do Piauí

Abstract Leptophlebiidae is the second most diverse family within Ephemeroptera, with species distributed across various States in Brazil, but with gaps in distribution records in others. Currently, nine species of Leptophlebiidae are recorded for the state of Piauí. Based on this information gap, the objective of this study was to present an updated species list of the family Leptophlebiidae new occurrence records and distributional sites for the state of Piauí, Brazil. By analyzing 447 specimens, we have significantly expanded our knowledge about the distribution of Leptophlebiidae species in the state of Piauí, increasing the recorded species from nine to 17. We have also added new occurrence records for six species and, for the first time, documented the presence of four genera. It is important to highlight that there is still an extensive area within the Cerrado and Brazilian semiarid regions where the occurrence of Ephemeroptera is unknown, confirming that the diversity in this area is underestimated and that knowledge of Ephemeroptera species and their distributions can expand with increased sampling efforts in the coming years, reducing the Linnean and Wallacean shortfall regarding this group. Our results also demonstrate the urgent need for inventories in the southern part of the state of Piauí, particularly in the sub-basins of the middle and upper Parnaíba river, which are considered suitable for monoculture expansion in Brazil.

Resumo Leptophlebiidae é a segunda família mais diversa de Ephemeroptera, com espécies distribuídas em vários estados do Brasil, mas com lacunas no registro de distribuição em outros. Por exemplo, no estado do Piauí tem registrado apenas nove espécies de Leptophlebiidae. Baseada nessa lacuna de informação, o objetivo deste estudo foi apresentar uma lista atualizada de espécies da família Leptophlebiidae, novos registros de ocorrência e sítios de distribuição para o estado do Piauí, Brasil. Ao analisar 447 exemplares, ampliamos significativamente nosso conhecimento sobre a distribuição das espécies de Leptophlebiidae no estado do Piauí, aumentando o número de espécies registradas de nove para 17. Também adicionamos novos registros de ocorrência para seis espécies e, pela primeira vez, documentamos a presença de quatro gêneros. Destacamos que ainda existe uma extensa área do Cerrado e semiárido brasileiro que se desconhece a ocorrência de Ephemeroptera, confirmando que a diversidade nessa área é subestimada e que o conhecimento sobre as espécies de Ephemeroptera e suas distribuições podem se expandir com o aumento do esforço amostral nos próximos anos, diminuindo as lacunas Lineana e Wallaceana sobre esse grupo. Nossos resultados também demonstram a necessidade emergencial de inventários no sul do Estado do Piauí, principalmente nas sub-bacias do médio e alto rio Parnaíba que é considerado adequado para a expansão da monocultura no Brasil.

The introduction of Physa acuta (Gastropoda: Physidae) on Ilha Grande, Southeast Brazil, from initial stages to an established population / A introdução de Physa acuta Draparnaud, 1805 (Gastropoda: Physidae) na Ilha Grande, Sudeste do Brasil, desde os estágios iniciais até uma população estabelecida

This study presents a four-year follow-up of an introduced population of Physa acuta Draparnaud, 1805, from initial stages to an established population. This introduction occurred on a small impacted stream of Vila do Abraão, the main village of Ilha Grande (Angra dos Reis, Rio de Janeiro, Brazil). The population size increased during the study, and presented a relationship to environmental factors, especially with rainfall. On the initial stages of introduction prevailed the smaller specimens, but on the overall, predominated the intermediate size classes. After less than a year, P. acuta becomes established on this stream and was possibly affecting the other species found on the stream. The information presented here is useful to understand the invasion process of invasive snails, as well as directing conservation efforts.

Neste estudo é apresentado um acompanhamento de quatro anos de uma população de Physa acuta Draparnaud, 1805, desde os estágios iniciais da introdução até seu pleno estabelecimento. Esta introdução ocorreu em um pequeno riacho impactado da Vila do Abraão, o principal vilarejo da Ilha Grande (Angra dos Reis, Rio de Janeiro, Brasil). A população cresceu durante o estudo, e apresentou uma relação com os fatores ambientais, especialmente a pluviosidade. Nos estágios iniciais de introdução prevaleceram os exemplares menores, contudo no panorama geral, predominaram as classes de tamanho intermediárias. Em menos de um ano de introdução, P. acuta se estabeleceu neste riacho, e possivelmente está afetando as demais espécies encontradas no rio. A informação apresentada aqui é importante para a compreensão do processo de invasão de moluscos invasores no Brasil, assim como no direcionamento de esforços de conservação.

The introduction of Physa acuta (Gastropoda: Physidae) on Ilha Grande, Southeast Brazil, from initial stages to an established population

Abstract This study presents a four-year follow-up of an introduced population of Physa acuta Draparnaud, 1805, from initial stages to an established population. This introduction occurred on a small impacted stream of Vila do Abraão, the main village of Ilha Grande (Angra dos Reis, Rio de Janeiro, Brazil). The population size increased during the study, and presented a relationship to environmental factors, especially with rainfall. On the initial stages of introduction prevailed the smaller specimens, but on the overall, predominated the intermediate size classes. After less than a year, P. acuta becomes established on this stream and was possibly affecting the other species found on the stream. The information presented here is useful to understand the invasion process of invasive snails, as well as directing conservation efforts.

Resumo Neste estudo é apresentado um acompanhamento de quatro anos de uma população de Physa acuta Draparnaud, 1805, desde os estágios iniciais da introdução até seu pleno estabelecimento. Esta introdução ocorreu em um pequeno riacho impactado da Vila do Abraão, o principal vilarejo da Ilha Grande (Angra dos Reis, Rio de Janeiro, Brasil). A população cresceu durante o estudo, e apresentou uma relação com os fatores ambientais, especialmente a pluviosidade. Nos estágios iniciais de introdução prevaleceram os exemplares menores, contudo no panorama geral, predominaram as classes de tamanho intermediárias. Em menos de um ano de introdução, P. acuta se estabeleceu neste riacho, e possivelmente está afetando as demais espécies encontradas no rio. A informação apresentada aqui é importante para a compreensão do processo de invasão de moluscos invasores no Brasil, assim como no direcionamento de esforços de conservação.

Sequence analysis of Paragonimus internal transcribed spacer 2 and cyclooxygenase 1 genes in freshwater crabs in Henan Province / 中国血吸虫病防治杂志

Objective To investigate the sequences of internal transcribed spacer 2 (ITS2) and cyclooxygenase 1 (COX1) genes of Paragonimus metacercariae in freshwater crabs in Henan Province, identify the species of Paragonimus and evaluate its genetic relationships with Paragonimus isolates from other provinces in China. Methods Freshwater crabs were collected from 8 survey sites in Zhengzhou, Luoyang, Pingdingshan, Nanyang and Jiyuan cities of Henan Province from 2016 to 2021, and Paragonimus metacercariae were detected in freshwater crabs. Genomic DNA was extracted from Paragonimus metacercariae, and the ITS2 and COX1 genes were amplified using PCR assay, followed by sequencing of PCR amplification products. The gene sequences were spliced and aligned using the software DNASTAR, and aligned with the sequences of Paragonimus genes in the GenBank. Phylogenetic trees were created using the MEGA6 software with the Neighbor-Joining method based on ITS2 and COX1 gene sequences, with Fasciola hepatica as the outgroup. Results The detection rates of Paragonimus metacercariae were 6.83% (11/161), 50.82% (31/61), 18.52% (5/26), 8.76% (12/137), 14.29% (9/63), 17.76% (19/105), 18.50% (32/173) and 42.71% (41/96) in freshwater crabs from 8 survey sites in Zhengzhou, Luoyang, Pingdingshan, Nanyang and Jiyuan cities of Henan Province, with a mean detection rate of 19.46% (160/822), and a mean infection intensity of 0.57 metacercariae/g. The amplified ITS2 and COX1 gene fragments of Paragonimus were approximately 500 bp and 450 bp in lengths, respectively. The ITS2 gene sequences of Paragonimus metacercariae from 8 survey sites of Henan Province showed the highest homology (99.8% to 100.0%) with the gene sequence of P. skrjabini (GenBank accession number: MW960209.1), and phylogenetic analysis showed that the Paragonimus in this study was clustered into the same clade with P. skrjabini from Sichuan Province (GenBank accession number: AY618747.1), Guangxi Zhuang Autonomous Region (GenBank accession number: AY618729.1) and Hubei Province (GenBank accession number: AY618751.1), and P. miyazaki from Fujian Province (GenBank accession number: AY618741.1) and Japan (GenBank accession number: AB713405.1). The COX1 gene sequences of Paragonimus metacercariae from 8 survey sites of Henan Province showed the highest homology (90.0% to 100.0%) with the gene sequence of P. skrjabini (GenBank accession number: AY618798.1), and phylogenetic analysis showed that the Paragonimus in this study was clustered into the same clade with all P. skrjabini and clustered into the same sub-clade with P. skrjabini from Hubei Province (GenBank accession numbers: AY618782.1 and AY618764.1). Conclusions Paragonimus species from freshwater crabs in Henan Province were all characterized as P. skrjabini, and the ITS2 and COX1 gene sequences had the highest homology to those of P. skrjabini from Hubei Province. The results provide insights into study of Paragonimus in Henan Province and China.

Preliminary application of recombinase -aided amplification in detection of Clonorchis sinensis metacercariae in freshwater fish / 中国血吸虫病防治杂志

Objective To evaluate the performance of recombinase-aided amplification (RAA) assay in detection of Clonorchis sinensis metacercariae in freshwater fish samples, so as to provide insights into standardization and field application of this assay. Methods Wild freshwater fish samples were collected in the rivers of administrative villages where C. sinensis-infected residents lived in Jiangyan District, Xinghua County and Taixing County of Taizhou City, Jiangsu Province from June to September 2022. Genomic DNA was extracted from six freshwater fish specimens (5 g each) containing 0, 1, 2, 4, 8 and 16 C. sinensis metacercariae for fluorescent RAA assay, and the diagnostic sensitivity was evaluated. Fluorescent RAA assay was performed with genomic DNA from C. sinensis, Metorchis orientalis, Haplorchis pumilio and Centrocestus formosanus metacercariae as templates to evaluate its cross-reactions. In addition, the detection of fluorescent RAA assay and direct compression method for C. sinensis metacercariae was compared in field-collected freshwater fish samples. Results Positive amplification was found in fresh-water fish specimens containing different numbers of C. sinensis metacercariae, and fluorescent RAA assay was effective to detect one C. sinensis metacercaria in 5 g freshwater fish specimens within 20 min. Fluorescent RAA assay tested negative for DNA from M. orientalis, H. pumilio and C. formosanus metacercariae. Fluorescent RAA assay and direct compression method showed 5.36% (93/1 735) and 2.88% (50/1 735) detection rates for C. sinensis metacercariae in 1 735 field-collected freshwater fish samples, with a statistically significant difference seen (χ2 = 478.150, P < 0.001). There was a significant difference in the detection of C. sinensis metacercariae in different species of freshwater fish by both the direct compression method (χ2 = 11.20, P < 0.05) and fluorescent RAA assay (χ2 = 20.26, P < 0.001), and the detection of C. sinensis metacercariae was higher in Pseudorasbora parva than in other fish species by both the direct compression method and fluorescent RAA assay (both P values < 0.05). Conclusions Fluorescent RAA assay has a high sensitivity for detection of C. sinensis metacercariae in freshwater fish samples, and has no cross-reactions with M. orientalis, H. pumilio or C. formosanus metacercariae. Fluorescent RAA assay shows a higher accuracy for detection of C. sinensis infections in field-collected freshwater fish than the direct compression method.

Which variables influence the herbivory amount on Montrichardia spp. (Araceae) in aquatic ecosystems? / ¿Qué variables influyen en la herbivoría en Montrichardia spp. (Araceae) en los ecosistemas acuáticos?

Abstract Introduction: The study of herbivory is fundamental in ecology and includes how plants invest in strategies and mechanisms to reduce herbivore damage. However, there is still a lack of information about how the environment, plant density, and functional traits influence herbivory in aquatic ecosystems. Objective: To assess if there is a relationship between herbivory, environmental variables, and plant traits two species of Montrichardia, a neotropical aquatic plant. Methods: In September 2018, we studied 78 specimens of Montrichardia arborescens and 18 of Montrichardia linifera, in 18 sites in Melgaço, Pará, Brazil. On each site, we measured water depth, distance to the margin, and plant density. From plants, we measured plant height and leaf thickness, and photographed the leaves to calculate the specific leaf area and percentage herbivory. To identify anatomical structures, we collected fully expanded leaves from three individuals per quadrat. Results: For M. arborescens, plants with thicker leaves and higher specific leaf area have less herbivore damage. For M. linifera, plants from deeper sites and with thicker leaves had more herbivore damage, while plants that grew farther from the margin had less damage. We found anatomical structures related to defense, such as idioblast cells with phenolic compounds, and cells with solid inclusions that can contribute to avoiding severe damage. Conclusions: Herbivory in these Montrichardia species can be explained by a combination of plant and environmental traits (patch isolation and water depth). The main plant traits are leaf thickness and area, but chemical compounds and solid inclusions also help Montrichardia to sustain less damage than other macrophytes.

Resumen Introducción: La herbivoría es fundamental para comprender cómo las plantas invierten en diferentes estrategias para evitar la depredación, lo que implica diferentes mecanismos de defensa. Factores relacionados con el medio ambiente, la densidad de plantas y/o los rasgos funcionales de las plantas pueden influir en la herbivoría en los ecosistemas acuáticos. Sin embargo, todavía falta información sobre cómo esos factores influyen en la herbivoría en los ecosistemas acuáticos y pueden contribuir a la carga de herbivoría. Objetivo: Evaluar si existe una relación entre la herbivoría y las variables ambientales (p. ej., profundidad del agua y distancia al margen), los factores ecológicos (densidad de plantas) y los rasgos estructurales de las plantas (altura, grosor de la hoja y área foliar) e indicar estructuras anatómicas que actúen junto con los rasgos estructurales en el sistema de defensa de especies de Montrichardia. Métodos: Se evaluaron 96 individuos de Montrichardia spp. (78 de M. arborescens y 18 de M. linifera, en 18 sitios) recolectados en septiembre de 2018. En cada sitio, se midió la profundidad del agua, la distancia al margen y la densidad de plantas. De los individuos, medimos la altura de la planta, el grosor de la hoja y fotografiamos las hojas para calcular el área foliar específica y la cantidad de herbivoría (en porcentaje). Para identificar las estructuras anatómicas relacionadas con la defensa de las plantas, se recogió hojas completamente expandidas de tres individuos por cuadrante. Resultados: Para M. arborescens, las plantas con hojas más gruesas y mayor área foliar específica tienen menos daño por herbivoría. Para M. linifera, las plantas con hojas más gruesas y que habitan en sitios más profundos tienen más daño por herbívoros, mientras que las plantas más alejadas del margen tienen menos daño por herbívoros. Se encontró estructuras anatómicas relacionadas con la defensa, como células idioblásticas con compuestos fenólicos y células con inclusiones sólidas que pueden contribuir a evitar daños severos en las características de las hojas. Conclusiones: Nuestros resultados indican que la herbivoría en las especies de Montrichardia podría explicarse por una combinación de características ambientales (aislamiento del parche y profundidad del agua) y de la planta. Descubrimos que los rasgos de las hojas eran factores importantes que impulsaban los cambios en la carga de herbivoría, especialmente el grosor de las hojas y el área foliar específica. Además, las especies de Montrichardia invierten en compuestos químicos e inclusiones sólidas para evitar daños graves en las hojas y, por lo tanto, pueden sufrir menos daños que otras especies de macrófitos.

Lista de especies de peces de la cuenca del río Ucayali, Perú

En este trabajo se presenta una lista actualizada de los registros de especies de peces de la cuenca del río Ucayali, Perú, provenientes de datos publicados y no publicados. Los resultados muestran que la cuenca del Ucayali presenta una ictiofauna rica y diversificada con el registro de 734 especies distribuidas en 15 órdenes, 49 familias y 292 géneros. La Ictiofauna está compuesta por peces miniatura (4%), peces pequeños (39%), medianos (41%), grandes (13%) y gigantes (3%). Los grupos dominantes son los Characiformes (312 especies, 43.0 %), Siluriformes (270 especies, 36.8%), Gymnotiformes (51 especies, 6.9%), y Cichliformes (50 especies, 6.8%). Parte de la ictiofauna es compartida con cuencas adyacentes como Marañón, y Amazonas peruano, principalmente en la región de confluencia, lo que contribuye a la notable diversidad de peces en la cuenca. Se observó una alta riqueza de especies con distribución restricta de los géneros Orestias, Astroblepus, Trichomycterus, Hemibrycon, entre otras especies, que ocurren en la región de cabeceras. Estimativos de riqueza de especies considerando su distribución por cada 100 m de altitud, indican que la cuenca del Ucayali esta subestimada, esperándose encontrar hasta 1125 especies. Los resultados aquí presentados son antecedentes que coadyuvaran a la toma de decisiones con fines de conservación y desarrollo sustentable en la región amazónica.

This study presents an updated checklists of the fish species recorded in the Ucayali River basin, Peru, from published and unpublished data. Ucayali River basin shows a rich and diversified ichthyofauna, with 734 species distributed in 15 orders, 49 families and 292 genera. It is composed by miniature fishes (4 %, < 2.6 cm of standard length), small fishes (39 %), medium fishes (41 %), large fishes (13 %) and giants (3 %). The dominant groups are Characiformes (312 species, 43.0 %), Siluriformes (270 species, 36.8 %), Gymnotiformes (51 species, 6.9 %) and Cichliformes (50 species, 6.8 %). Part of the ichthyofauna is shared with the adjacent basins as Marañón and Amazon, mainly in the confluence area, which contribute to the highest diversity of fishes in the Ucayali basin. High diversity of fishes with restricted distribution was observed, among them Orestias, Astroblepus, Trichomycterus, Hemibrycon genera that occur in the headwaters. Estimates of species richness considering their distribution per 100 m of altitude, show that the Ucayali basin is underestimated, expecting to find up to 1125 species. The results presented here are background information that will contribute to decision-making for conservation and sustainable development purposes in the Amazon region.

Prevalencia de Fasciola hepatica y Paramphistomidae en bovinos de doble propósito en una hacienda del trópico bajo andino colombiano / Prevalence of Fasciola hepatica and Paramphistomidae in dual purpose cattle in a farm in the Colombian low Andean tropic

RESUMEN En muchos países la fasciolosis y la paramfistomosis representan un grave problema para la salud del sector pecuario. En Colombia hay registros de ambas distomatosis en bovinos, la mayoría en el trópico alto andino, las cuales generan pérdidas econômicas anuales cercanas a 40 000 000 000 COP. El objetivo de esta investigación fue determinar la prevalencia de fasciolosis y paramfistomosis en vacunos de la hacienda La Candelaria, Caucasia (Colombia), y la presencia de caracoles hospederos intermediarios. Para cumplirlo, se realizó un estudio descriptivo de corte transversal con muestreo no probabilístico por conveniencia. Se recolectaron heces de los animales y se hizo el diagnóstico mediante la técnica modificada de Dennis. Se establecieron las prevalencias de los digeneos de acuerdo con el sexo, peso, edad y raza. Se recolectaron caracoles dulciacuícolas en la zona estudiada y se identificaron por morfologia. Se analizaron 466 muestras fecales de 178 bovinos, de las razas Cebú (Bos indicus), BON (blanco orejinegro) y del cruce entre ellas. Se diagnosticaron F. hepatica y Paramphistomidae con prevalencias del 2,2% y 30,9%, respectivamente. En el 1,1% de los vacunos se diagnosticó coinfección. Ambas trematodosis prevalecieron en las hembras (p = 0,03). Se identificaron moluscos dulciacuícolas Ampullariidae, Physidae y Planorbidae sin estadios larvarios de digeneos. Se concluyó que los bovinos de doble propósito de la hacienda La Candelaria están expuestos a F. hepatica y Paramphistomidae, y, probablemente, se infectan en los predios de la hacienda. Paramphistomidae es más prevalente que F. hepatica, lo cual concuerda con lo descrito en algunos estudios realizados en hatos del trópico alto andino colombiano. Paramphistomidae se encontró en todos los grupos etarios.

ABSTRACT Fasciolosis and paramphistomosis are a major health problem for the livestock economy worldwide. In Colombia, both distomatosis are reported in cattle, particularly in high Andean tropics, with annual economic losses close to COP 40 billion. The goal of this study was to determine the prevalence of fasciolosis and paramphistomosis in cattle from La Candelaria farm, Caucasia (Colombia), and the presence of intermediate host snails. A descriptive cross-sectional study was carried out with non-probability convenience sampling. Stool samples were collected from the animals and the diagnosis was made using the modified Dennis technique. Digenea prevalence were determined according to sex, weight, age, and race. Freshwater snails were collected in the studied area and were identified by morphology. 400 and 66 fecal samples from 178 bovines of the Zebu (Bos indicus), BON (white-eared white) breeds and the cross between them were analyzed. Fasciola hepatica and Paramphistomidae were diagnosed with a prevalence of 2,2% and 30,9%, respectively. Coinfection was diagnosed in 1,1% of the cattle. Both trematodosis were most frequent in females (p = 0,03). Freshwater molluscs Ampullariidae, Physidae and Planorbidae without digenea larval stages were identified. It was concluded that dual-purpose cattle from La Candelaria farm are exposed to F. hepatica and Paramphistomidae and are probably infected on the farm grounds. Paramphistomidae was more prevalent than F. hepatica, which agrees with other studies in herds from the Colombian high Andean tropics. Paramphistomidae was found in all age groups.

Digestibilidad aparente de materia seca, proteína y carbohidratos de la dieta con ensilado biológico de harina de maíz en Cryphiops (C.) caementarius / Apparent digestibility of dry matter, protein and carbohydrate of the diet with biological corn meal silage in Cryphiops (C.) caementarius

Resumen El objetivo del estudio fue determinar la digestibilidad aparente de la materia seca, proteína y carbohidratos de la dieta con ensilado biológico de harina de maíz en Cryphiops (C.) caementarius. Camarones adultos (4.50 a 7.20 cm de longitud total), se colectaron del río Pativilca (Lima, Perú) y en laboratorio se mantuvieron en recipientes individuales instalados dentro de seis acuarios (cuatro camarones por acuario). La dieta control fue sin ensilado y para la dieta experimental se reemplazó el 75% de la harina de maíz por el ensilado biológico de harina de maíz; ambas dietas tuvieron 1% de óxido crómico como marcador inerte. Los camarones fueron alimentados dos veces por día (40% a las 08:00 h y 60% a las 18:00 h) con el 6% del peso húmedo, durante 10 días. Para la colección de heces, los camarones fueron trasladados a un sistema de caja cribada (12 compartimentos) instalada dentro de un acuario. La digestibilidad aparente se determinó en base seca. Los camarones alimentados con la dieta con ensilado biológico de harina de maíz tuvieron altos coeficientes de digestibilidad aparente de carbohidratos (95.69%), proteína cruda (80.02%) y materia seca (76.19%), que aquellos alimentados con la dieta sin ensilado (p<0.05) que fue de 93.48, 78.21 y 74.36%, respectivamente. Los camarones adultos digieren con eficiencia los carbohidratos de la dieta con ensilado biológico de harina de maíz, en vez de la proteína de dicha dieta.

Abstract The aim of this study was to determine the apparent digestibility of dry matter, protein and carbohydrates of the diet with biological corn meal silage in Cryphiops (C.) caementarius. Adult prawn (4.50 to 7.20 cm total length) was collected from the Pativilca river (Lima, Peru) and in the laboratory each shrimp was kept in individual containers set up in six aquaria (four prawn per aquarium). The experimental diet was supplemented with corn meal biological silage and the control diet was without silage; both diets had 1% chromic oxide. Each diet had three replicates. Prawn was fed twice a day (40% at 08:00 h and 60% at 18:00 h) at 6% of wet weight for 10 days. For feces collection, the prawn was transferred to a system of sieved boxes (12 compartments) installed inside an aquarium. Apparent digestibility was determined on a dry basis. Prawn fed the diet with corn meal biological silage had higher apparent digestibility coefficient for carbohydrates (95.69%), crude protein (80.02%) and dry matter (76.19%) than those fed the diet without silage (p<0.05), which was 93.48, 78.21 and 74.36%, respectively. The adult prawn digested efficiently the carbohydrates of the corn meal biological silage diet, instead of the protein of this diet.

Fish community turnover in a dammed Andean River over time

We describe the change in the fish community of the Porce River in Magdalena River Basin, Colombia, following the construction of the Porce III hydropower reservoir based on 13 years of monitoring data. The results show a clear reduction of the number of native species, which have been supplanted by colonizing non-native species, especially in the reservoir. Four native species detected prior to dam construction have apparently disappeared, but 12 new species were registered post-construction. We analyzed spatial changes in beta diversity in the aquatic environments surrounding the dam. The new environment generated by the reservoir presents a unique species composition and contributes significantly to the total beta diversity of the system. Altogether three distinct new fish assemblages emerged following reservoir formation and there are now six assemblages where there had previously been three. This dramatic change, already visible within a decade of construction, highlights just how strong of an impact dam construction has on habitats and how rapidly fish communities react in this hotspot for endemic fish diversity. Our findings demonstrate the importance of monitoring fish communities for revealing the impact of damming on river ecosystems and informs potential complementary fish diversity inventories elsewhere in the Magdalena River basin.(AU)

Describimos el cambio en la comunidad de peces del río Porce en la cuenca del río Magdalena en Colombia luego de la construcción del embalse hidroeléctrico Porce III con base en 13 años de datos de monitoreo. Los resultados mostraron una reducción de especies nativas y, el embalse ha sido colonizado por especies no nativas. A lo largo del monitoreo cuatro especies desaparecieron de las capturas, y se registró la aparición de 12 especies nuevas después de la construcción del embalse. Analizamos los cambios espaciales en la diversidad beta en los ambientes acuáticos que rodean la presa. El nuevo entorno generado por el embalse presenta una composición de especies única; en total, surgieron tres nuevos ensamblajes de peces distintos después de la formación del embalse y ahora hay seis ensamblajes. Este cambio, ya visible a una década de la construcción, resalta cuán fuerte es el impacto que tiene la construcción de presas en los hábitats y cuán rápido reaccionan las comunidades de peces. Nuestros hallazgos demuestran la importancia de monitorear las comunidades de peces para revelar el impacto de las represas en los ecosistemas fluviales, además permite complementar los inventarios de diversidad en la cuenca del río Magdalena.(AU)

Parasites and diet of Serrasalmus maculatus in a hydroelectric reservoir in Brazil / Parasitos e dieta de Serrasalmus maculatus em um reservatório no Brasil

Abstract Serrasalmus maculatus is a species of piranha which, despite being abundant in a reservoir environment, has few studies related to its parasitological and diet aspects. Thus, we aimed to document the parasitic fauna and diet of the S. maculatus in a hydroelectric reservoir in Brazil. In addition, we perform two literature reviews for the Neotropical region, recording the parasitic fauna already associated with S. maculatus and the occurrence of parasite genera identified in this study parasitizing Characiformes from other aquatic systems. Thirty-one hosts were collected with gillnets, from August 2014 to September 2016. Serrasalmus maculatus had a piscivorous feeding habit and a low richness parasitic component community, including two taxa of monogeneans, Anacanthorus lepyrophallus and Mymarothecium sp.; no endohelminths were observed. Data from the literature review, together with the findings of the study, showed that S. maculatus in the Neotropical region harbors 25 helminth taxa, with the monogenean being the most prevalent parasitic group and Brazil is the country with the most reports of the parasitic genera. These findings provide information on the relationships between diet, social behavior, and parasitic fauna of S. maculatus and on the patterns of distribution and infection of the observed parasite rates.

Resumo Serrasalmus maculatus é uma espécie de piranha que, a despeito de ser abundante em ambiente de reservatório, possui poucas informações sobre seus aspectos parasitológicos e dieta. Assim, o presente estudo objetivou documentar a fauna parasitária e a dieta de S. maculatus em um reservatório brasileiro. Além disso, foram realizadas duas revisões literárias para a região Neotropical, registrando a fauna parasitária, já associada a S. maculatus e a ocorrência dos gêneros parasitários identificados neste estudo, registrados em outros peixes Characiformes em outros sistemas aquáticos. Foram coletados 31 hospedeiros com redes de espera entre agosto de 2014 e setembro de 2016. Serrasalmus maculatus apresentou hábito alimentar piscívoro e comunidade componente parasitária com baixa riqueza, incluindo dois táxons de monogenéticos, Anacanthorus lepyrophallus e Mymarothecium sp.; não foram observados endohelmintos. Dados da revisão da literatura, juntamente com os achados deste estudo, mostraram que S. maculatus, na região Neotropical, abriga 25 táxons de helmintos, sendo monogenéticos o grupo de parasitos mais prevalente, e o Brasil o país com mais relatos de parasitos. Estes resultados fornecem informações sobre as relações entre dieta, o comportamento social e a fauna parasitária de S. maculatus e sobre os padrões de distribuição e infecção das taxas de parasitos observadas.

Ecology and diversity of metazoan parasites infecting Geophagus altifrons (Cichliformes: Cichlidae) from the Amazon River system in northern Brazil / Ecologia e diversidade de parasitos metazoários infectando Geophagus altifrons (Cichliformes: Cichlidae) do sistema do Rio Amazonas no norte do Brasil

Abstract The aim of this study was to investigate the ecology and diversity of community and infracommunities of metazoan parasites Geophagus altifrons (Heckel, 1840) in Rio Jari, in the state of Amapá, in the eastern Amazon region. From the total of 31 fish examined, 90.3% were parasitized by one or more species, collecting a total number of 806 parasites. The parasites species identified were: Sciadicleithrum geophagi, Posthodiplostomum sp., Procamallanus (Spirocamallanus) inopinatus, Raphidascaris (Sprentacaris) sp., Genarchella genarchella, Gorytocephalus spectabilis and Ergasilus xinguensis. Most of the parasites showed an aggregate dispersion pattern. Brillouin diversity index, uniformity and species richness of parasites were low. The component community of parasites was constituted by ectoparasites and endoparasites, but with a predominance of ectoparasites. The body size of hosts had a low effect on the parasites infracommunities. This first eco-epidemiological study for G. altifrons reports these parasites in a host, for the first time, with the exception of S. geophagi and E. xinguensis.

Resumo O objetivo deste estudo foi investigar a ecologia e a diversidade da comunidade e infracomunidades de parasitos metazoários em Geophagus altifrons (Heckel, 1840), do Rio Jari, estado do Amapá, na região da Amazônia oriental. De um total de 31 peixes examinados, 90,3% estavam parasitados por uma ou mais espécies e 806 parasitos foram coletados. As espécies de parasitos identificadas foram: Sciadicleithrum geophagi, Posthodiplostomum sp., Procamallanus (Spirocamallanus) inopinatus, Raphidascaris (Sprentacaris) sp., Genarchella genarchella, Gorytocephalus spectabilis e Ergasilus xinguensis. A maioria dos parasitos apresentaram dispersão agregada. Foi baixo o índice de diversidade de Brillouin, uniformidade e riqueza de espécies de parasitos. A comunidade componente de parasitos foi constituída por ectoparasitos e endoparasitos, mas com predominância de ectoparasitos. O tamanho corporal dos hospedeiros teve baixo efeito sobre as infracomunidades dos parasitos. Este primeiro estudo ecoepidemiológico para G. altifrons registra pela primeira vez estes parasitos para este hospedeiro, exceto S. geophagi e E. xinguensis.

Morphological and molecular characterization of Austrodiplostomum compactum metacercariae in the eyes and brains of fishes from the Ivaí River, Brazil / Caracterização morfológica e molecular de metacercárias de Austrodiplostomum compactum em olhos e cérebros de peixes do Rio Ivaí, Brasil

Abstract Austrodiplostomum spp. (Platyhelminthes: Digenea) are endoparasites with a broad geographic distribution in South America. During the larval stage, they parasitize the eyes, brains, muscles, gill, kidneys and swim bladder of a wide variety of fishes. The metacercariae of Austrodiplostomum spp. have several morphological characteristics during development, but are very similar among species, which makes it necessary to use molecular tools to contribute to the elucidation during the larval stage. The objective of this study was to perform morphological and molecular analyses of Austrodiplostomum sp. found in specimens of Hypostomus sourced from the Ivaí River in the state of Paraná, Brazil. Of the 93 analyzed specimens (H. hermanni [n = 50], H. albopunctatus [n = 9], Hypostomus sp. 1 [n = 24], and Hypostomus sp. 2 [n = 10]), 60 were parasitized. A total of 577 Austrodiplostomum sp. metacercariae was collected from the infected hosts; DNA from seven of these samples was extracted, amplified, and sequenced. The morphological data associated with the genetic distance values and the relationships observed in the COI gene tree, indicate that all metacercariae were A. compactum. This is the first record of A. compactum parasitizing H. hermanni, H. albopunctatus, Hypostomus sp. 1, and Hypostomus sp. 2 in the Ivaí River.

Resumo Austrodiplostomum spp. (Platyhelminthes: Digenea) são endoparasitos com uma ampla distribuição geográfica na América do Sul. Durante a fase larval, parasitam os olhos, cérebros, músculos, brânquias, rins e bexiga natatória de uma grande variedade de peixes. As metacercárias de Austrodiplostomum spp. apresentam várias características morfológicas durante o desenvolvimento, as quais são muito semelhantes entre as espécies, o que torna necessário o uso de ferramentas moleculares para contribuir para a elucidação durante a fase larval. O objetivo deste estudo foi realizar análises morfológicas e moleculares de Austrodiplostomum sp. encontradas em espécimes de Hypostomus provenientes do rio Ivaí, no Paraná, Brasil. Dos 93 espécimes analisados (H. hermanni [n = 50], H. albopunctatus [n = 9], Hypostomus sp. 1 [n = 24], e Hypostomus sp. 2 [n = 10]), 60 foram parasitados. Um total de 577 metacercárias de Austrodiplostomum foram coletadas dos hospedeiros infectados; o DNA de sete dessas amostras foi extraído, amplificado e sequenciado. Os dados morfológicos, associados aos valores de distância genética e as relações observadas na árvore gênica do COI, indicam que todas as metacercárias são A. compactum. Este é o primeiro registo de A. compactum parasitando H. hermanni, H. albopunctatus, Hypostomus sp. 1, e Hypostomus sp. 2 no rio Ivaí.

Detection of bloodworm larvae (Diptera: Chironomidae) in the golden apple snail Pomacea canaliculata (Lamarck, 1819) (Gastropoda: Ampullariidae) in Metro Manila

Background@#Pomacea canaliculata (Lamarck, 1819) is an invasive freshwater snail in the Philippines that damages crops but is consumed as food. It is known to harbor parasites, some of which are pathogenic to humans. @*Objectives@#The objective of this study is to examine P. canaliculata individuals present in Metro Manila for parasite infection and identify the parasites and other organisms associated with the snail using molecular identification. @*Methodology@#P. canaliculata were collected from rivers and marketplaces in Metro Manila. Individuals were crushed and digested in Ash's digestive fluid and observed under a microscope. Collected parasites were subjected to DNA barcoding of the COI gene for putative identification. @*Results@#A total of 462 snails were gathered from 15 sites, eight of which were market areas that sourced the snails from outside Metro Manila. No known parasites were found. Two snails were found to contain insect larvae in the mantle (0.43% infection). The closest BLAST matches for the two insect larvae were the chironomid fly Nilodorum tainanus (91.0% identity) from a snail in Sucat, Muntinlupa, and another chironomid Parachironomus sp. (92.8% identity) found in a snail originally from Cavite and brought to Calumpang, Marikina. @*Conclusion@#This study is the first report of the presence of chironomids in Philippine P. canaliculata. This could have an impact on the allergenic status of these mollusks if consumed while containing these chironomids. The absence of infection of other medically important parasites is possibly due to the patchy distribution of the snails and few interactions with the definitive hosts of known parasites.