Sustainability of dual exploitation (fry and adults) of the fish Semaprochilodus laticeps (Characiformes: Prochilodontidae) in Colombia / Sostenibilidad de la explotación dual (alevines y adultos) del pez Semaprochilodus laticeps (Characiformes: Prochilodontidae) en Colombia

Abstract Introduction: Semaprochilodus laticeps is a freshwater fish species native to the Orinoco Basin that is exploited in Colombia at two different stages of its life cycle: fry (for the ornamental trade) and adults (for the consumer market). This double exploitation of juveniles and adults raises concerns about the population stability of the species. Objective: To evaluate the sustainability of the exploitation of the species in these two life stages. Methods: 1 277 specimens of S. laticeps were sampled between June and December 2017. Population parameters were estimated from length-frequency data using ELEFAN 1 routine of the FISAT II package. Length at first maturity (Lm) and length at maximum yield (Lopt) were determined using the Froese and Binohlan equations. Virtual population analysis was performed based on Jones length cohort analysis. Results: Population parameters were as follows: K = 0.75, L∞ = 53.1 cm LE, Z = 2.92 yr-1, M = 1.24 yr-1 and F = 1.68. Lm was estimated to be 29.6 cm SL and Lopt at 33.4 cm SL. Of note, 96.3 % of the fish caught in the consumer fishery exceeded Lm and 80 % exceeded Lopt. The results of the virtual population analysis suggested that a very low proportion (0.85 %) of the population was caught as fry, possibly due to natural mortality. Conclusions: Based on the results, as no indicators of overexploitation were identified, it is recommended to continue with the dual use of S. laticeps. It is recommended to maintain the existing conservation measures, such as the closed season during the reproductive period, to ensure sustainable fishery exploitation. The results obtained can serve as a reference to analyze the situation of other species currently fished for both the ornamental (fry) and food (adult) markets.

Resumen Introducción: Semaprochilodus laticeps es una especie de pez de agua dulce originaria de la cuenca del Orinoco, explotada en Colombia en dos etapas distintas de su ciclo de vida: alevín (para el comercio ornamental) y adulto (para el mercado de consumo). Esta doble explotación de alevines y adultos genera preocupación sobre la estabilidad poblacional de la especie. Objetivo: Evaluar la sostenibilidad de la explotación de la especie en estas dos etapas de vida. Método: Entre junio y diciembre de 2017 se muestrearon 1 277 ejemplares de S. laticeps. Los parámetros poblacionales se estimaron utilizando datos de frecuencia de tallas con la rutina ELEFAN 1 del paquete FISAT II. La longitud de primera madurez (Lm) y la de máximo rendimiento (Lopt) se determinaron mediante ecuaciones de Froese y Binohlan. El análisis de la población virtual se realizó basándose en el análisis de cohorte de longitud de Jones. Resultados: Los parámetros poblacionales fueron los siguientes: K = 0.75, L∞ = 53.1 cm LE, Z = 2.92 año-1, M = 1.24 año-1 y F = 1.68. Lm se estimó en 29.6 cm SL y Lopt en 33.4 cm SL. En particular, el 96.3 % del pescado capturado en la pesquería de consumo superó Lm y el 80 % superó Lopt. El análisis de la población virtual sugirió que una fracción muy baja (0.85 %) de la población fue capturada como alevines, posiblemente atribuible a la mortalidad natural. Conclusiones: Con base en los hallazgos, al no identificarse indicadores de sobreexplotación, se recomienda continuar con el doble uso de S. laticeps. Se recomienda mantener las medidas de protección existentes, así como una veda durante el período reproductivo, para garantizar una explotación pesquera sostenible. Los resultados obtenidos pueden servir como referencia para analizar la situación de otras especies actualmente capturadas para el mercado tanto ornamental como de consumo.

Trophic ecology of Brycon henni (Pisces: Bryconidae) in Nare and Guatapé Rivers, Magdalena River basin, Colombia / Ecología trófica de Brycon henni (Pisces: Bryconidae) en afluentes de los Ríos Nare y Guatapé, cuenca del río Magdalena, Colombia

ABSTRACT Understanding the trophic ecology of fish and how they use resources in space and time is important to support conservation and management actions. The trophic ecology of Brycon henni in the Nare and Guatapé rivers, Magdalena river basin, Colombia was determined. Five field samplings were carried out between October 2007 and January 2010, in rainy, dry, and dry-to-rainy transition periods. Stomachs of 262 specimens were collected. A Kruskall-Wallis analysis and a Mann-Whitney pairwise comparison test was performed to detect differences in the alimentary importance index of each food category between sex, size class, hydrological period and basins (Nare vs Guatapé). The Levin's Measure of Niche Breadth and the Morisita's Diet Overlapping Index were calculated to establish differences between size class in the different hydrological periods. Vegetable material was the most important food item, followed by Insecta, and fish. Individuals from Guatapé basin consumed more plant material and fish and fewer insects. We observed increased consumption of plant material and fish in ontogeny. Levin's niche breadth was lower and diet overlapping between individuals of length classes was higher during rainy period because the diet was mainly based on plant material. The diet of B. henni was composed mainly of plant material and Insects, and to a lesser extent from other groups such as fish, crustaceans and arachnids.

RESUMEN La comprensión de la ecología trófica de los peces y la forma en que utilizan los recursos en el espacio y en el tiempo es importante para la toma de acciones para su conservación y manejo. Se determinó la ecología trófica de Brycon henni en los ríos Nare y Guatapé, cuenca del río Magdalena, Colombia. Se realizaron cinco muestreos entre octubre de 2007 y enero de 2010, en periodos de lluvia, seca y transición de seca a lluvia. Se recolectaron estómagos de 262 ejemplares. Para detectar diferencias en el índice de importancia alimentaria de cada categoría de alimentos entre sexo, clase de talla, período hidrológico y cuencas se realizó un análisis de Kruskall-Wallis y una prueba de Mann-Whitney. Se calculó la amplitud del nicho de Levin y el Índice de superposición de dieta de Morisita para establecer diferencias entre clases de talla en diferentes períodos hidrológicos. El material vegetal fue el alimento más importante, seguido de Insecta y peces. Los individuos de la cuenca del Guatapé consumieron más material vegetal y peces, y menos insectos. Se detectó mayor consumo de material vegetal y de peces en individuos de mayor tamaño. La amplitud de nicho fue menor y la superposición entre clases de talla fue mayor en temporada de lluvias porque la dieta se basó principalmente en material vegetal. La dieta de B. henni estuvo compuesta principalmente por material vegetal e insectos y en menor proporción de otros grupos como peces, crustáceos y arácnidos.

Metazoan parasite fauna of detritivorous and omnivorous fishes from Amapá Lake, in western Brazilian Amazon / Fauna parasitária de metazoários em peixes detritívoros e onívoros do Lago Amapá, na Amazônia Ocidental brasileira

Abstract Despite being an important component of the freshwater ecosystems and an important factor controlling wild fish populations, Amazonian fish parasites have been poorly studied. Here, we analyzed the fauna of metazoan parasites from 10 detritivorous and omnivorous fish species from Amapá Lake in the western Amazon. Of 159 fish specimens examined, 73.6% were parasitized by one or more species of metazoan parasites. A total of 5,260 parasites (24 Monogenea, 14 Nematoda, 10 Digenea, 2 Acanthocephala, and 6 Crustacea) were identified. Aggregated dispersion pattern of parasites was observed. There was a predominance of endohelminth species that presented a similar pattern regarding the level of component communities (i.e., a low species number, low diversity and dominance of a single species, mainly the digeneans and nematodes in their larval stages). Five species of parasites presented correlation with the body size of the hosts. In the fish community, the presence of endoparasites in the larval and adult stages suggests that these are intermediate, paratenic and definitive hosts, reflecting their detritivorous or omnivorous feeding habits. The trophic level and diet had an influence on the structuring of endohelminth communities and infracommunities. Lastly, 38% of the metazoan parasite species were new records for examined hosts.

Resumo Apesar de ser um importante componente dos ecossistemas de água doce e um importante fator controlador das populações naturais de peixes, os parasitos de peixes amazônicos ainda são pouco estudados. Foi analisada a fauna de parasitos metazoários em 10 espécies de peixes detritívoros e onívoros do Lago Amapá na Amazônia ocidental. Dos 159 espécimes de peixes examinados, 73,6% estavam parasitados por uma ou mais espécies de parasitos metazoários. Um total de 5.260 parasitos (24 Monogenea, 14 Nematoda, 10 Digenea, 2 Acanthocephala e 6 Crustacea) foram identificados. Houve um padrão de dispersão agregado de parasitos. Houve predominância de espécies de endohelmintos que apresentaram padrão semelhante quanto ao nível de comunidades componentes, ou seja, baixo número de espécies, baixa diversidade e dominância de uma única espécie, principalmente os digenéticos e nematoides em estágio larval. Cinco espécies de parasitos apresentaram correlação com o tamanho corporal dos hospedeiros. Na comunidade de peixes, a presença de endoparasitos em fase larval e adulta sugere que esses são hospedeiros intermediários, paratênicos e definitivos, refletindo seus hábitos alimentares detritívoros ou onívoros. O nível trófico e dieta influenciaram na estruturação das comunidades e infracomunidades de endohelmintos. Por fim, 38% das espécies de parasitos metazoários foram novos registros para os hospedeiros examinados.

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.

CRYOPRESERVED SEMEN OF Piaractus orinoquensis (Serrasalmidae): POST-THAW STORAGE TIMES AND ACTIVATING SOLUTIONS / Semen congelado de Piaractus orinoquensis (Serrasalmidae): Almacenamiento posdescongelación y soluciones activadoras

ABSTRACT Piaractus orinoquensis is a native species from the Colombian Orinoquia and several studies have contributed to the standardization of protocols for seminal cryopreservation of this species. The main goal of this study was to evaluate the sperm motility, duration of sperm motility (DM), pH, sperm membrane integrity (SMI) and fertility of semen cryopreserved for seven years and subjected to different post-thaw storage times (PST). Semen from five males (3.04 ± 0.3 kg) was diluted 1:4 (semen:diluent) with 10 % dimethylsulfoxide, 5.5 % glucose and 12 % egg yolk in 4 mL macrotubes and frozen in liquid nitrogen. Four PST were evaluated: 0, 15, 45 and 60 min. The sperm cells were activated with 1 % NaHCO3 (SB) and 0.9 % NaCl (SC) to determine sperm motility, DM, fertility rate, SMI and pH through PST. Significative motility reduction (p < .05) was observed through the PST and between the PST of 0 and 60 min for DM, both for treatments activated with SB and with SC. The SMI had a significant reduction (p < .05) after 60 min of post-thaw storage and the pH did not vary during PST. The fertility rate decreased significantly (p < .05) between time 0 and 60 min of PST. PST affects the seminal quality and fertility of P. orinoquensis, the best fertilization results were obtained by activating post-thawing sperm motility with 1 % SB. The long-term cryopreserved semen (seven years) of the species maintains its fertilization capacity with values like those obtained with fresh sperm.

RESUMEN Piaractus orinoquensis es una especie de la Orinoquía Colombiana en la cual se han realizado numerosos estudios para estandarizar protocolos de crioconservación seminal. El objeto de este estudio fue evaluar la motilidad espermática, duración de la motilidad espermática (DM), pH, integridad de membrana espermática (SMI) y fertilidad de semen crioconservado por siete años, sometido a diferentes tiempos de almacenamiento posdescongelación (PST). Semen de 5 machos (3,4 ± 0,3 kg) fue diluido 1:4 (semen: diluyente) con dimetilsulfóxido 10 %, glucosa 5,5 %, yema de huevo 12 %, en macrotubos de 4 mL y congelado en nitrógeno líquido. Cuatro PST fueron evaluados: 0, 15, 45 y 60 min. Las células espermáticas fueron activadas con NaHCO3 1% (SB) y NaCl 0,9 % (SC) para determinar motilidad espermática, DM, tasa de fertilización, SMI y pH a través de PST. Se observó reducción significativa de motilidad (p < ,05) a través del PST, también en DM entre tiempo 0 y tiempo 60 min. de PST en semen activado con SB y SC. SMI tuvo una reducción significativa (p < ,05) luego de 60 min. de almacenamiento posdescongelación y el pH no varió durante el PST. La tasa de fertilización decayó significativamente (p < ,05) entre 0 y 60 minutos de PST. La calidad seminal y fertilidad en P. orinoquensis fue afectada por PST. Los mejores resultados de fertilización se obtuvieron activando la motilidad con SB. El semen crioconservado a largo plazo (siete años), conservó su capacidad fertilizante con valores similares a los obtenidos con semen fresco.

Evaluation of Muscle Proximate Composition and Nutritional Value of Six Freshwater Fish Species

Fish is an economically viable source of animal protein that is widely available even in rural areas, making it an easily accessible source of protein. The aim of the present study was to determine the proximate composition and nutritional value of 6 different freshwater species of fishes: Orechromis nitoticus, Labeo rohita, Ompok bimaculatus, Notopterus chitala, Channa striata, and Catla catla. The study was conducted from March to September 2022. Nutritional and economic factors were taken into account in the selection of the fish types. According to our findings, dry fish has high-protein content and low-fat which can contribute greatly to children's as well as adult’s recommended protein intake. Fish nutritional value varies significantly depending on the species, size, and age of the fish, but understanding the proximate composition of the fish can provide us with a general idea of its nutritional profile. The data that has been summarized could prove to be beneficial for further studies to determine how dry fish can be utilized effectively to combat malnutrition issues in India and also shares an insight into nutritional values of different fresh water fishes available in the Kalaburagi region.

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.

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.

A new species of Phanerothecium (Monogenea, Oogyrodactylidae), in Hypostomus regani (Loricariidae) from southeast Brazil / Uma nova espécie de Phanerothecium (Monogenea, Oogyrodactylidae), de Hypostomus regani (Loricariidae) do sudeste do Brasil

Abstract: A new species of Phanerothecium Kritsky & Thatcher, 1977 (Oogyrodactylidae Harris, 1983) is described from locariid fish from southeast Brazil. Phanerothecium macrosomum n. sp. (Oogyrodactylidae) is described from the body surface of Hypostomus regani (Ihering, 1905) (Loricariidae). It is characterized by an armed male copulatory organ containing spines of different size from proximal to distal extremity, short peduncle and robust haptor.

Resumo: Uma nova espécie de Phanerothecium Kritsky & Thatcher, 1977 (Oogyrodactylidae Harris, 1983) é descrita em peixes locariídeos do sudeste do Brasil. Phanerothecium macrosomum sp. n. (Oogyrodactylidae) é descrito da superfície corporal de Hypostomus regani (Ihering, 1905) (Loricariidae) e é caracterizado pela presença de órgão copulador masculino armado contendo espinhos de diferentes tamanhos da extremidade proximal à distal, pedúnculo curto e haptor robusto.

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.

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.

Trophic relationships among three species of ornamental fish from the region of Lake Amanã, Amazon / Relações tróficas entre três espécies de peixes ornamentais da região do lago de Amanã, Amazonas

The present study objectified to evaluate the trophic relationships and the possible aggressive mimicry involving Carnegiella strigata, Carnegiella marthae and Gnathocharax steindachneri, in lowland forest streams. Samplings occurred in November 2002, March and August 2003 in Amanã Sustainable Development Reserve (ASDR). The total of 943 fish was caught, being 79.43% of C. marthae, 3.18% of C. strigata and 17.39% of G. steindachneri. Stomach contents, degree of stomach repletion, relative volume and frequency of occurrence of food items were evaluated. Thirteen food items were identified, and the presence of terrestrial and aquatic insects indicates the high dependence of these species and the flooded forest. Low feeding overlap was observed between Carnegiella strigata and C. marthae compared to Gnathocharax steindachneri. However, the overlap between the two Carnegiella species was relatively high, which could explain the low frequency of syntopic occurrence among these species, suggesting a possible case of competitive exclusion.

Este estudo teve como objetivo analisar as relações tróficas e a possível existência de uma relação de mimetismo agressivo envolvendo Carnegiella strigata, Carnegiella marthae e Gnathocharax steindachneri, em igarapés de terra firme. As coletas ocorreram em novembro de 2002, março e agosto de 2003 e foram realizadas na Reserva de Desenvolvimento Sustentável de Amanã (RDSA). Foram capturados 943 peixes, onde C. marthae representou 79,43%, C. strigata 3,18% e G. steindachneri 17,39%. Foram analisados os conteúdos estomacais e verificados grau de repleção, volume relativo e frequência de ocorrência dos alimentos. Foram identificados 13 itens alimentares, onde insetos terrestres e aquáticos denotaram alto grau de dependência destas espécies em relação à floresta alagada. Ocorreu baixa sobreposição alimentar das espécies Carnegiella strigata e C. marthae em relação a Gnathocharax steindachneri. Entretanto, a sobreposição entre as duas espécies de Carnegiella foi relativamente alta, o que poderia explicar a baixa frequência de ocorrência sintópica entre essas espécies, sugerindo um possível caso de exclusão competitiva.

Trophic relationships among three species of ornamental fish from the region of Lake Amanã, Amazon

Abstract The present study objectified to evaluate the trophic relationships and the possible aggressive mimicry involving Carnegiella strigata, Carnegiella marthae and Gnathocharax steindachneri, in lowland forest streams. Samplings occurred in November 2002, March and August 2003 in Amanã Sustainable Development Reserve (ASDR). The total of 943 fish was caught, being 79.43% of C. marthae, 3.18% of C. strigata and 17.39% of G. steindachneri. Stomach contents, degree of stomach repletion, relative volume and frequency of occurrence of food items were evaluated. Thirteen food items were identified, and the presence of terrestrial and aquatic insects indicates the high dependence of these species and the flooded forest. Low feeding overlap was observed between Carnegiella strigata and C. marthae compared to Gnathocharax steindachneri. However, the overlap between the two Carnegiella species was relatively high, which could explain the low frequency of syntopic occurrence among these species, suggesting a possible case of competitive exclusion.

Resumo Este estudo teve como objetivo analisar as relações tróficas e a possível existência de uma relação de mimetismo agressivo envolvendo Carnegiella strigata, Carnegiella marthae e Gnathocharax steindachneri, em igarapés de terra firme. As coletas ocorreram em novembro de 2002, março e agosto de 2003 e foram realizadas na Reserva de Desenvolvimento Sustentável de Amanã (RDSA). Foram capturados 943 peixes, onde C. marthae representou 79,43%, C. strigata 3,18% e G. steindachneri 17,39%. Foram analisados os conteúdos estomacais e verificados grau de repleção, volume relativo e frequência de ocorrência dos alimentos. Foram identificados 13 itens alimentares, onde insetos terrestres e aquáticos denotaram alto grau de dependência destas espécies em relação à floresta alagada. Ocorreu baixa sobreposição alimentar das espécies Carnegiella strigata e C. marthae em relação a Gnathocharax steindachneri. Entretanto, a sobreposição entre as duas espécies de Carnegiella foi relativamente alta, o que poderia explicar a baixa frequência de ocorrência sintópica entre essas espécies, sugerindo um possível caso de exclusão competitiva.

Geographic range, distribution patterns and interactions of Monogenea Van Beneden 1858, with species of native host freshwater fishes from Brazil / Distribuição geográfica, padrões de distribuição e interações de Monogenea Van Beneden 1858, com espécies de peixes hospedeiros nativos de água doce do Brasil

Abstract This paper investigated information on monogenean species using 312 scientific papers, to search for infection and geographic distribution patterns in native freshwater fish from Brazil. We used 1,698 samples of 296 fish species of 28 families distributed into Characiformes, Siluriformes, Cichliformes, Gymnotiformes, Perciformes, Mugiliformes, Osteoglossiformes and Clupeiformes, in addition to four hybrid fish. Among the hosts of the different orders and families, the greatest numbers of parasite-host associations were found for species of the families Serrasalmidae, Characidae, Loricariidae, Curimatidae and Anostomidae. The 578 species of monogeneans used in parasite-host interactions were distributed in 86 genera of six five families (Dactylogyridae, Gyrodactylidae, Diplectanidae, Microcotylidae, Ancylodiscoididae and Ancyrocephalidae), but with great predominance of Dactylogyridae species. There was variation in prevalence, intensity and abundance levels of monogeneans species among host fish species, as well as in infection sites that occurred predominantly in external organs. Positive correlations of prevalence, intensity and abundance with body length of hosts were observed. There was geographic distribution pattern of monogeneans limited mostly to two hydrographic basins those being the Amazon River and Paraná River. Just approximately 6% of potential monogeneans have been explored thus far, showing a clear need for further studies on this interesting group of parasites.

Resumo Este estudo investigou informações sobre espécies de monogenéticos, usando 312 artigos científicos para buscar padrões de infecção e distribuição geográfica em peixes nativos de água doce do Brasil. Foram utilizadas 1.698 amostras de 296 espécies de peixes de 28 famílias, distribuídas em Characiformes, Siluriformes, Cichliformes, Gymnotiformes, Perciformes, Mugiliformes, Osteoglossiformes e Clupeiformes, além de quatro peixes híbridos. Entre os hospedeiros das diferentes ordens e famílias, os maiores números de associações parasito-hospedeiro foram encontrados para espécies das famílias Serrasalmidae, Characidae, Loricariidae, Curimatidae e Anostomidae. As 578 espécies de monogenéticos, utilizadas nas interações parasito-hospedeiro, foram distribuídas em 86 gêneros de seis famílias (Dactylogyridae, Gyrodactylidae, Diplectanidae, Microcotylidae, Ancylodiscoididae e Ancyrocephalidae), mas com grande predominância de espécie de Dactylogyridae. Houve variação nos níveis de prevalência, intensidade e abundância das espécies de monogenéticos entre as espécies de peixes hospedeiros, bem como nos locais de infecção que ocorreram predominantemente em órgãos externos. Correlações positivas de prevalência, intensidade e abundância com o comprimento corporal dos hospedeiros foram observadas. Houve padrão de distribuição geográfica dos monogenéticos limitados principalmente a duas bacias hidrográficas, sendo elas o Rio Amazonas e Rio Paraná. Apenas aproximadamente 6% dos potenciais monogenéticos são conhecidos até agora, mostrando uma clara necessidade de mais estudos sobre esse interessante grupo de parasitos.

Trophic relationships among three species of ornamental fish from the region of Lake Amanã, Amazon / Relações tróficas entre três espécies de peixes ornamentais da região do lago de Amanã, Amazonas

The present study objectified to evaluate the trophic relationships and the possible aggressive mimicry involving Carnegiella strigata, Carnegiella marthae and Gnathocharax steindachneri, in lowland forest streams. Samplings occurred in November 2002, March and August 2003 in Amanã Sustainable Development Reserve (ASDR). The total of 943 fish was caught, being 79.43% of C. marthae, 3.18% of C. strigata and 17.39% of G. steindachneri. Stomach contents, degree of stomach repletion, relative volume and frequency of occurrence of food items were evaluated. Thirteen food items were identified, and the presence of terrestrial and aquatic insects indicates the high dependence of these species and the flooded forest. Low feeding overlap was observed between Carnegiella strigata and C. marthae compared to Gnathocharax steindachneri. However, the overlap between the two Carnegiella species was relatively high, which could explain the low frequency of syntopic occurrence among these species, suggesting a possible case of competitive exclusion.

Este estudo teve como objetivo analisar as relações tróficas e a possível existência de uma relação de mimetismo agressivo envolvendo Carnegiella strigata, Carnegiella marthae e Gnathocharax steindachneri, em igarapés de terra firme. As coletas ocorreram em novembro de 2002, março e agosto de 2003 e foram realizadas na Reserva de Desenvolvimento Sustentável de Amanã (RDSA). Foram capturados 943 peixes, onde C. marthae representou 79,43%, C. strigata 3,18% e G. steindachneri 17,39%. Foram analisados os conteúdos estomacais e verificados grau de repleção, volume relativo e frequência de ocorrência dos alimentos. Foram identificados 13 itens alimentares, onde insetos terrestres e aquáticos denotaram alto grau de dependência destas espécies em relação à floresta alagada. Ocorreu baixa sobreposição alimentar das espécies Carnegiella strigata e C. marthae em relação a Gnathocharax steindachneri. Entretanto, a sobreposição entre as duas espécies de Carnegiella foi relativamente alta, o que poderia explicar a baixa frequência de ocorrência sintópica entre essas espécies, sugerindo um possível caso de exclusão competitiva.

High prevalence and intensity of fish nematodes with zoonotic potential in the Brazilian Amazon, including a brief reflection on the absence of human infections

This study aimed to characterize the prevalence, mean abundance, and mean intensity of potential fish-borne zoonotic nematode larvae infecting the predator fish Hoplias aff. malabaricus from the Tapajós River, in the municipality of Santarém, in the Brazilian Amazon. After capture, the specimens of H. aff. malabaricus were analyzed for infection by Contracaecum sp. and Eustrongylides sp. third-stage larvae, and the prevalence, mean abundance, and mean intensity were calculated. A literature search was carried out to clarify the relationship between these indicators and eventual human cases of infection in the Amazon region. Third-stage larvae of nematodes of the Contracaecum and Eustrongylides genera were found in the specimens of H. aff. malabaricus sampled from the Tapajós River. The prevalence of Contracaecum larvae was 100%, while its mean abundance and mean intensity were both 54.8 larvae/fish. The prevalence of Eustrongylides larvae was 62.9%, and its mean abundance and mean intensity were 1.8 and 2.8 larvae/fish, respectively. Despite the high prevalence and intensity values, there are no cases of human infection by these nematode larvae in the Brazilian Amazon reported. The absence of human infections by these nematode larvae in the Brazilian Amazon despite the high prevalence/intensity of Contracaecum and Eustrongylides larvae and the high consumption of fish in the region, is most probably due to the fact that the local populations do not eat raw or undercooked fish. However, it is noteworthy that the absence of zoonotic cases in the region is based only on the examination of the available published papers. A better knowledge of the situation would require surveying hospitals and clinics, and data from the region's medical treatment facilities. However, the authors consider that cases of human infection, if any, are extremely rare, mainly due to the eating habits of the local population.

Distribution of freshwater fish from the Southern Neotropics reveals three new areas of endemism and show diffuse limits among freshwater ecoregions

Ecoregions and areas of endemism are central concepts in biogeography. Based on collection records and the Endemic Analyses implemented with NDM/VNDM method we analyzed fish areas of endemism in the junction of three freshwater ecoregions related to the Rio de la Plata estuary (Lower Parana, Lower Uruguay, Laguna dos Patos) in Southern Neotropical region. Using two grid cell sizes, results obtained showed the same general patterns. Areas of endemism recovered were mainly associated either to Lower Uruguay or to Laguna dos Patos. In both ecoregions nested areas of endemism were identified within larger patterns of endemism. Noteworthy, one area recovered occurred across Lower Uruguay and Laguna dos Patos limits. Our results also suggest a revision of the Lower Uruguay and Lower Parana ecoregion limits, and highlight the relevance of the Rio de la Plata estuary as a barrier and corridor for freshwater fishes in the area.(AU)

Las ecorregiones y áreas de endemismo son conceptos centrales en biogeografía. Basados en registros de colecciones y el análisis de endemismo implementado en NDM/VNDM, analizamos áreas de endemismo de peces en el sur de la región Neotropical, en la conjunción de tres ecorregiones de agua dulce relacionadas al estuario del Río de la Plata (Bajo Paraná, Bajo Uruguay, Laguna de los Patos). Usando dos tamaños de grilla, los resultados obtenidos mostraron los mismos patrones generales. Las áreas de endemismo obtenidas estuvieron principalmente asociadas tanto a la ecorregión Bajo Uruguay como a la Laguna de los Patos. En los dos casos, fueron identificadas áreas de endemismo anidadas dentro de los grandes patrones de endemismo. Además, se destacó un área que atravesó los límites de ambas ecorregiones. Nuestros resultados también sugieren que es necesaria una revisión de los límites entre Bajo Uruguay y Bajo Paraná y resaltan la relevancia del estuario del Río de la Plata como barrera y corredor para los peces de agua dulce de esta región.(AU)

Diversity and community ecology of metazoan parasites in Pimelodus ornatus (Siluriformes: Pimelodidae) from the Amazonas River in Brazil / Diversidade e ecologia da comunidade de parasitos metazoários em Pimelodus ornatus (Siluriformes: Pimelodidae) do Rio Amazonas no Brasil

Abstract The present study investigated the metazoan parasite community in Pimelodus ornatus from the Amazon River, in the state of Amapá (Brazil). Of 71 fish examined, 70.4% were parasitized by Demidospermus sp. (Monogenea), Cucullanus pinnai, Procamallanus (Spirocamallanus) inopinatus and Contracaecum sp. (Nematoda) and plerocercoids from Proteocephalidae gen. sp. (Cestoda). The dominance was of nematode species such as Procamallanus (S.) inopinatus and Contracaecum sp. The parasites showed a highly aggregated dispersion and a predominance of hosts infected by one species of parasite. The parasite community was characterized by a low Shannon diversity index, low evenness and low species richness. The richness of parasite species, Shannon's diversity index, abundance of P. (S.) inopinatus and Proteocephalidae gen. sp. showed a positive correlation with the length of the hosts. Therefore, the size of the hosts had an influence on the parasite community and infracommunities, as well as their intermediate position in the food web. This is the first record of P. (S.) inopinatus and Contracaecum sp. for P. ornatus.

Resumo Este estudo investigou a comunidade de parasitos metazoários em Pimelodus ornatus do Rio Amazonas, no estado do Amapá (Brasil). De 71 peixes examinados, 70,4% estavam parasitados. Um total de 147 parasitos foi coletado, entre Demidospermus sp. (Monogenea), Cucullanus pinnai (Nematoda), Procamallanus (Spirocamallanus) inopinatus e Contracaecum sp. (Nematoda) e plerocercoides de Proteocephalidae gen. sp. (Cestoda). A dominância foi de nematoides como Procamallanus (S.) inopinatus e Contracaecum sp. Os parasitos apresentaram dispersão altamente agregada e predomínio de hospedeiros infectados por uma espécie de parasito. A comunidade de parasitos foi caracterizada por baixo índice de diversidade de Shannon, baixa equitabilidade e baixa riqueza de espécies. A riqueza de espécies de parasitos, índice de diversidade de Shannon, abundância de P. (S.) inopinatus e Proteocephalidae gen. sp. apresentaram correlação positiva com o comprimento dos hospedeiros. Portanto, o tamanho dos hospedeiros teve influência sobre a comunidade e infracomunidades de parasitos, bem como sua posição intermediária na cadeia alimentar. Este é o primeiro registro de P. (S.) inopinatus e Contracaecum sp. para P. ornatus.

Reproductive biology of seven fish species of commercial interest at the Ramsar site in the Baixada Maranhense, Legal Amazon, Brazil

The purpose of this study is to determine the parameters of the reproductive biology of seven commercial species at the Ramsar Site of the Baixada Maranhense to support fisheries management measures. The collections were carried out between 2012 and 2016. The reproductive period, sex ratio, weight-length relationship and first sexual maturity were evaluated for seven species of commercial importance. The sex ratio showed that females are predominant for all species, except for Plagioscion squamossissimus. The weight-length relationship indicated a greater investment in weight for Cichla monoculus and Hassar affinis, and a greater investment in length for Hoplias malabaricus, Plagioscion squamosissimus, Prochilodus lacustris, Pygocentrus nattereri, and Schizodon dissimilis. The reproductive activity of the species was predominant in the rainy season, but C. monoculus, H. malabaricus and P. lacustris showed the ability to reproduce in both seasons. As management measures for the region, it is suggested a change in the closed fishing season established by IBAMA, from December 1 to April 30, to ensure the protection of all commercial species in this study.(AU)

Este estudo teve como objetivo determinar os parâmetros da biologia reprodutiva de sete espécies comerciais no Sítio Ramsar da Baixada Maranhense, para apoiar medidas de manejo pesqueiro. As coletas foram realizadas entre 2012 e 2016, com um ano de coleta para cada espécie. Foram avaliados o período reprodutivo, a razão sexual, a relação peso-comprimento e a primeira maturidade sexual para sete espécies de importância comercial. A razão sexual mostrou que as fêmeas são predominantes para todas as espécies, exceto para Plagioscion squamossissimus. A relação peso-comprimento indicou um maior investimento em peso para Cichla monoculus e Hassar affinis, e um maior investimento em comprimento para Hoplias malabaricus, Plagioscion squamosissimus, Prochilodus lacustris, Pygocentrus nattereri e Schizodon dissimilis. A atividade reprodutiva das espécies foi predominante na estação chuvosa, mas C. monoculus, H. malabaricus e P. lacustris mostraram capacidade de se reproduzir nas duas estações. Como medidas de manejo para a região, sugere-se uma mudança do período de defeso, estabelecida pelo IBAMA, de 1 de dezembro a 30 de abril, para garantir a proteção de todas as espécies comerciais.(AU)