Ectoparasite crustaceans of ten fish species from the upper Araguari River in northern Brazil.

Fish parasites are an important part of aquatic biodiversity and knowing these species and their interactions with their hosts helps in monitoring the aquatic biota. The present study investigated the ectoparasite crustacean fauna of ten fish species from the upper Araguari River, in the state of Amapá, northern Brazil. A total of 508 fish were collected and analyzed from July to November 2014, of which 82.6% (109) were parasitized by one or more crustacean ectoparasite species. In the ten host fish species, a total of 308 ectoparasite specimens were collected, from 12 taxa, such as Argulus multicolor Stekhoven, 1937, Argulus spinulosus Silva, 1980, Argulus sp.1, Argulus sp.2, Argulus sp.3, Dipteropeltis sp., Dipteropeltis hirundo Calman, 1912, Dolops bidentata Bouvier, 1899, Dolops striata Bouvier, 1899 (Argulidae), Braga fluviatilis Richardson, 1911, Braga amapaensis Thatcher, 1996 (Cymothoidae) and Excorallana berbicensis Boone, 1918 (Corallanidae). Higher levels of prevalence and abundance were recorded for Hoplias aimara (Valenciennes, 1847) and Tometes trilobatus Valenciennes, 1850, respectively. These ectoparasites were found in the fins, integument, mouth, and anus of the host fish. Argulus sp.2 and D. bidentata were the most abundant parasites (65.1%), and had the highest species richness. This study registered 36 novel host-parasite interactions, and thus represents a new record for all host species here examined.

Morphological and functional structure of two Ergasilidae parasites determine their microhabitat affinity on the gills of an Anostomidae fish from the Amazon.

The aim of this study was to investigate the microhabitat affinities of Ergasilus sp. and Therodamas longicollum on the gills of Leporinus fasciatus ("aracu-piau"), an anostomid fish from the Amazon. A total of 143 specimens of L. fasciatus were examined, of which 35% had their gills parasitized by at least one ergasilid species. A total of 159 specimens of Ergasilus sp. and 97 specimens of T. longicollum were recovered. Both ergasilids species exhibited a greater affinity for attachment in arch 1 of the gills of the host. There was a negative correlation between the abundance of Ergasilus sp. and the abundance of T. longicollum within each gill arch. Analysis of distribution along the gill arch showed a higher occurrence of Ergasilus sp. in Section 5, while T. longicollum occurred mainly in Section 3 of the gills. There was a positive correlation between the abundance of these ectoparasites and the size of the gill arch. Ergasilus sp. occurred only on the filament of the gill arch and exhibited affinity for the proximal region, while T. longicollum occurred only in the gill arch itself. The results reveal that these two parasite species compete in the gills of the host without the overlapping of their niches.

Proactively averting the collapse of Amazon fisheries based on three migratory flagship species.

Migratory species are the most important commercial fishes in the Amazon. They are also now the most threatened directly by some combination of overfishing, floodplain deforestation, and dam construction. Limited governmental monitoring and implemented regulations impede adequate management of the fisheries at adequate scale. We summarize the current stock status of the three most heavily exploited long-distance migratory species, which are two goliath catfishes (Brachyplatystoma rousseauxii and B. vaillantii) and the characiform Colossoma macropomum. In addition, we analyze impacts beyond overfishing on these species. Our results indicate: (i) the overfishing trends for these important species are either ominous or indicate the verge of collapse of the commercial fisheries based on them, and (ii) a dangerous synergy between overfishing, hydroelectric dams, and floodplain deforestation further challenge fisheries management of migratory species in the Amazon. We propose eight direct governmental actions as a proactive approach that addresses the main impacts on the fisheries. We consider that the most practical way to assess and manage overfishing of migratory species in the short run in an area as large as the main commercial fishing area in the Amazon is at market sites where enforced regulations can control fish catch. The management of the three species considered here has implications beyond just their sustainability. Their management would represent a paradigm shift where the governments assume their legal responsibilities in fishery management. These responsibilities include regulation enforcement, data collecting, inter-jurisdictional cooperation to protect migratory species at realistic life history scales, mitigation of the Madeira dams to assure goliath catfish passage to the largest western headwater region, and recognition of monitoring and managing wetland deforestation for the protection of fish and other aquatic and terrestrial biodiversity.

Length-weight relationship and condition factor for twelve fish species from the Igarapé Fortaleza basin, a small tributary of the Amazonas River estuary

Length and weight data are useful in fisheries management and standard results of fish monitoring programs. Length-weight relationship (LWR) is used for estimating the weight corresponding to a given length, and the condition factor is used to compare the body condition, fatness or health of fish populations. This study aimed to estimate the LWR and the condition factor for 12 freshwater fish species from the Igarapé Fortaleza basin, a tributary of the Amazonas River system in the State of Amapá, eastern Amazon (Brazil). The coefficient of determination, the allometric condition factor and the allometric coefficient varied among species, and were compared with populations elsewhere. In 83.3% of the species, the allometric coefficient remained within the expected range. This was the first record of LWR parameters for Acestrorhynchus falcirostris. (AU)

Length-weight relationship and condition factor of eight fishspecies from the upper Araguari River, State of Amapá, Brazil

The present study estimated parameters of the length-weight relationship (LWR) and allometric condition factor for eight fish species from the upper Araguari River, in the State of Amapá, Brazil. A total of 615 fish of eight species were analyzed: Acestrorhynchus falcatus, A. falcirostris, Ageneiosus inermis, Hemiodus unimaculatus, Hoplias aimara, Myloplus asterias, M. ternetzi and Tometes trilobatus. The allometric condition factor varied from 0.742 to 1.435. The coefficient of allometry ranged from 2.723 to 3.225. The coefficient of determination (R2) of the LWR ranged from 0.742 to 0.985. This is the first estimate of the length-weight relationship for fish from the Araguari River and the first record of these parameters for Myloplus ternetzi and Tometes trilobatus.

Population dynamics of the yellow piranha Serrasalmus spilopleura Kner, 1858 (Characidae, Serrasalminae) in Amazonian floodplain lakes / Dinâmica populacional da piranha amarela Serrasalmus spilopleura em lagos de várzea

Fish is the main source of protein in the Amazon and fishing is one of the most important sources of income for the Amazonian population. Serrasalmus spilopleura is a species that have been increasingly consumed by riverside communities, although it is only occasionally commercialized at regional markets. Therefore, this work sought to generate information about the population biology of S. spilopleura captured in floodplain lakes, Jaitêua and São Lourenço, in Manacapuru, Amazonas State. The population parameters were estimated by analyzing the distribution of the length frequency with the help of the ELEFAN I routine of the FISAT II program. The weight/length relationship was estimated by linear regression, longevity by Taylor's method, rate of natural mortality by Taylor's and Pauly's methods, and growth type by a t-test (α = 0.05). 669 specimens of S. spilopleura were captured measuring between 7 and 22 centimeters. The estimated population parameterswere:k=0.34year-1,L 23.10 cm, t0 = 0, and A0.95 = 9 years. 7 cohorts were identified, Taylor M = 0.33 year-1 and Pauly M = 0.98 year-1. The weight/length relationship equation was Wt = 0.051320.Lt2.8727, and negatively allometric growth. The information on the population parameters of S. spilopleura could be used to provide evaluation models for this fishery resource.

O pescado é a principal fonte de proteína e uma das mais importantes fontes de renda da população na Amazônia. Serrasalmus spilopleura é uma das espécies consumidas pelos ribeirinhos, embora seja ocasionalmente comercializada nos mercados e feiras da região. Portanto, o trabalho propõe gerar informações da biologia populacional de S. spilopleura capturadas nos lagos Jaitêua e São Lourenço na região de Manacapuru, AM. Os parâmetros populacionais foram estimados através da análise de distribuição de frequência de comprimento com o auxilio da rotina ELEFAN I do programa FISAT II. A relação peso-comprimento foi estimada por regressão linear e verificado o tipo de crescimento pelo teste-t (α = 0,05), a longevidade pelo método de Taylor e a mortalidade natural pelos métodos de Taylor e Pauly. Foram capturados 669 exemplares de S. spilopleura variando entre 7 e 22 cm de comprimento padrão. Os parâmetros populacionais estimados foram: k = 0,34 ano-1, L∞ = 23.10 cm, t0 = 0, A0.95 = 9 anos, sete coortes identificadas, Taylor M = 0,33 -1ano, Pauly M = 0,98 ano-1, a equação da relação peso/comprimento foi Wt = 0,051320.Lt2.8727 e o tipo de crescimento alométrico negativo. As informações geradas sobre os parâmetros populacionais de S. spilopleura poderão ser utilizados para subsidiar modelos de avaliação desse recurso pesqueiro.

Reprodução da piranha-amarela Serrasalmus spilopleura Kner, 1858, em lagos de várzea, Amazonas, Brasil / Reproduction of piranha Serrasalmus spilopleura Kner, 1858, on the floodplain lakes, Amazon, Brazil

Serrasalmus spilopleura (piranha-amarela) é fonte de proteína animal para as populações ribeirinhas, sendo ocasionalmente comercializada nos mercados e feiras da região. Considerando a escassez de informações sobre a reprodução de peixes em lagos de várzea, o trabalho propõe investigar o comprimento médio de primeira maturação sexual e a época de desova de S. spilopleura nos lagos Jaitêua-São Lourenço, Manacapuru, AM. Também são relacionados os fatores abióticos (nível de água e profundidade) e bióticos (fator de condição) com a época de desova. Foram capturadas 232 fêmeas no período de agosto de 2006 a junho 2007, utilizando rede-de-emalhar e, em laboratório, foram realizadas as biometrias e identificação dos estádios de maturação gonadal. A época de desova das fêmeas foi estabelecida através da distribuição temporal da freqüência relativa nos diferentes estádios de maturação gonadal e do fator de condição relativo, Kn = Pt/aCp b, onde: Kn = fator de condição relativo; Pt = peso total; Cp = comprimento padrão e, a e b = constantes obtidas da regressão entre peso e comprimento. E, para verificar se há correlação entre o fator de condição e época de desova com a profundidade dos lagos, utilizou-se o coeficiente de correlação de Spearman ao nível de significância 5 por cento. A amplitude do comprimento padrão dos exemplares variou de 7 a 22 cm. A análise de correlação entre o Kn e a época de desova foi positiva (r s = 0,58, p < 0,05), ou seja, a época de desova correspondeu ao período de maior Kn, sugerindo ser um indicador para época de desova de S. spilopleura. Houve correlação negativa entre a profundidade e o Kn (r s = -0,66, p < 0,05) e entre a profundidade e a época de desova (r s = -0,25, p < 0,05). O L50 estimado correspondeu a 13,0 cm ± 0,09 e o L100 a 17,0 cm ± 0,02. S. spilopleura desenvolve o seu ciclo reprodutivo no complexo lacustre lago Grande de Manacapuru, e com base nos indicadores reprodutivos, época de desova e fator de condição relativo, a desova começa em dezembro, logo no início da enchente, se estendendo até fevereiro, meados de enchente, coincidindo com a elevação do nível da água do rio Solimões-Amazonas e da profundidade nos lagos.

Serrasalmus spilopleura (piranha) is a source of animal protein for marginal populations, it is occasionally sold in markets and fairs in the region. Considering the scarcity of information on reproduction of fish in floodplain lakes, the study proposes to investigate the average size at first maturity and spawning season of S. spilopleura lakes Jaitêua-São Lourenço, Manacapuru, AM. Also related are the abiotic factors (water level and depth) and biotic (condition factor) with the spawning season. 232 females were captured from August 2006 to June 2007, using gill net, and in the laboratory were used for biometrics and identification of the maturation stages. The spawning season of the females was established through the temporal distribution of relative frequency in different maturation stages and relative condition factor, Kn = Pt/aCp b, where: Kn = relative condition factor; Pt = total weight; Cp = standard length, a and b = constants obtained from regression between weight and length. And, to check for correlation between condition factor and with the spawning season depth of the lakes, we used the Spearman correlation coefficient of the 5 percent significance level. The amplitude of the standard length of specimens ranged 7-22 cm. Correlation analysis between Kn and spawning season (r s= 0.58, p < 0.05) was positive, i.e. the spawning season corresponded to the higher Kn, suggesting that an indicator of spawning season of S. spilopleura. There was a negative correlation between the depth and Kn (r s = -0.66, p < 0.05) and between depth and spawning season (r s = -0.25, p < 0.05). The estimated L50 corresponded to 13.0 ± 0.09 cm and 17.0 ± 0.02 cm L100, S. spilopleura develops its complex reproductive cycle in the lake of Grand Lake Manacapuru, and based on indicators of reproduction, spawning season and relative condition factor, spawning begins in December, early on the rising extending to February, mid-rising, which coincided with the rise of water level of the Solimões-Amazon River and deep lakes.

Dinâmica populacional de Triportheus albus, T. angulatus e T. auritus (CHARACIFORMES: CHARACIDAE) em lagos da Amazônia Central / Dynamic population from Triportheus albus, T. angulatus and T. auritus (CHARACIFORMES: CHARACIDAE) in Amazonian Central lakes

Na Amazônia brasileira a pesca é importante fonte de renda e proteína animal para as populações ribeirinhas. E, entre as espécies de peixes de maior volume desembarcado nos mercados e feiras da região se destacam as sardinhas, Triportheus albus, T. angulatus e T. auritus. Considerando o aumento da pressão pesqueira, que gera a redução de alguns estoques pesqueiros na região, tanto na quantidade como no tamanho de algumas espécies, o trabalho propõe determinar os parâmetros de crescimento, mortalidade e relação peso-comprimento dessas espécies em lagos de várzea, Manacapuru, AM. Os parâmetros foram estimados através da análise de distribuição de frequência de comprimento com o auxílio da rotina "scan de valores de k" do método ELEFAN I do programa FISAT II. Os valores calculados foram: T. albus L∞ = 24,68 cm, k = 0,86/ano, Ø´ = 2,71, A0,95 = 3,48 anos, Mp = 1,76/ano, Mt = 0,85/ano, Pt = 0,0398I Cp2,6303; T. angulatus L∞ = 26,78 cm, k = 0,77/ano, Ø´ = 2,74, A0,95 = 3,89 anos, Mp = 1,60/ano, Mt = 0,76/ano, Pt = 0,0294I Cp2,8599; T. auritus L∞ = 27,83 cm, k = 0,65/ano, Ø´ = 2,70, A0,95 = 4,68 anos Mp = 1,40/ano, Mt = 0,63/ano e Pt = 0,0542I Cp2,5094. Essas espécies apresentaram crescimento rápido, mortalidade elevada, baixa expectativa de vida e ciclo de vida curto. É sugerido o monitoramento desses parâmetros para que possam ser utilizados como instrumentos de análise dos estoques pesqueiros.

In the Amazon the fishing is considered an important source of income and animal protein for the people in the region. Among the different fish species that landed in the market and fairs stand out Triportheus albus, T. angulatus and T. auritus. Considering the reduction of some fish stocks in the region, both the quantity and the size of some species, the research proposes to determine the growth parameters, mortality and length-weight relation of these species in floodplain lakes, Manacapuru, AM. The parameters were estimated by analyzing the length frequency distribution with the help of the routine "scan of values of k" method ELEFAN I program FISAT II. The values for each species were: T. albus L∞ = 24.68 cm, k = 0.86/year, Ø '= 2.71, A0.95 = 3.48 years, Mp = 1.76/year, Mt = 0.85/year, Pt = 0.0398I Cp2.6303; T. angulatus L∞ = 26.78 cm, k = 0.77/year, Ø '= 2.74, A0.95 = 3.89 years, Mp = 1.60/year, Mt = 0.76/year, Pt = 0.0294 I Cp2.8599 and T. auritus L∞ = 27.83 cm, k = 0.65/year, Ø '= 2.70, A0.95 = 4.68 years, Mp = 1.40/year, Mt = 0.63/year and Pt = 0.0542I Cp2.5094. These species showed rapid growth, high mortality, low life expectancy and short life cycle. It is suggested the parameters population should be continuously monitored to be used as a tool in the stock analysis.