Effect of seasonality and estuarine waters on the phytoplankton of the Guamá River (Belém, Amazon, Brazil).

This study aimed to analyze the application of the Phytoplankton Community Index-PCI and Functional Groups-FG in determining the water quality of the Guamá River (Pará, Amazônia, Brazil). Samplings occurred monthly for analyses of phytoplankton and physical and chemical parameters, for two years, at the station where water was collected for human supply consumption. Seasonality influenced electrical conductivity, total suspended solids, dissolved oxygen, transparency, winds, true color, and N-ammoniacal. The ebb tide showed high turbidity and suspended solids. The density varied seasonally with the highest values occurring in September and December (61.1 ind mL-1 and 60.2 ind mL-1, respectively). Chlorophyll-a was more elevated in December (21.0 ± 4.7 µg L-1) and chlorophyll-c higher in relation to clorophyll- b indicated the dominance of diatoms. Functional Group P prevailed in the study months. Through the PCI índex the waters of Guamá River varied from reasonable to excellent and the TSI ranged from oligo to mesotrophic. The use of Functional Groups proved to be a promising tool in the determination of water quality since it covered the most abundant species in the Environment, but the PCI is not adequate to characterize Amazonian white-waters rivers, which have diatoms as the leading dominant group.

Dietary effect of multi-strain prebiotics and probiotics on growth, hemato-biochemical parameters, intestinal histomorphometry, and resistance to hypoxia in juvenile tambaqui (Colossoma macropomum).

This study evaluated the effects of a multi-strain prebiotics and probiotics on the diet of tambaqui Colossoma macropomum. One hundred and fifty juvenile tambaqui (20.2 ± 3.6 g and 10.32 ± 5.78 cm) were randomly distributed in 15 experimental units with a volume of 80 L and fed for 45 days with a diet containing the symbiotic additive at five inclusion levels (0, 2, 4, 6 and 8 g kg feed- 1). At the end of the period, growth performance, survival, hemato-biochemical and intestinal parameters, as well as the fish's resistance to stress were evaluated. The additive did not alter the growth performance, hemato-biochemical and intestinal parameters of the tambaqui. However, the hemato-biochemical parameters of aspartate aminotransferase (AST), plasma protein, hematocrit, glucose, triglycerides and cholesterol showed differences between treatments after the stress challenge. AST increased significantly during challenge and post-challenge. Plasma protein increased significantly during and after the challenge. The hematocrit was highest at 48 h after the challenge and lowest in the 2 g, 6 g and 8 g groups. Glucose was significantly reduced 24 h after the challenge, while triglycerides were lower 24 h and 48 h after the challenge. Cholesterol increased significantly in the challenge. There was an interaction between the factors sampling time and symbiotic concentration for hematocrit and glucose. In hypoxic stress situations, the 2 g concentration was more favorable for the fish. We recommend further studies with 2 g kg feed- 1 in trials lasting more than 45 days.

Growth, survival, and myogenic gene expression in the post-larvae of Colossoma macropomum provisioned with Artemia nauplii.

Artemia nauplii are widely used as fish larvae feed due to its beneficial nutritional characteristics for larval development; however, efficient feeding strategies are needed to balance its high costs. Therefore, we evaluated the effects of different densities of Artemia nauplii (100, 250, 500, 750, and 1000 nauplii/post-larvae) on the growth, survival, water quality, and myogenic gene expression of tambaqui (Colossoma macropomum) post-larvae cultivated in a recirculating aquaculture system. After 2 weeks of trial, there was a significant decrease in dissolved oxygen concentration with the increase in nauplii density, but it did not interfere with larval performance and survival. In the first week, larvae fed with fewer than 500 nauplii/post-larvae presented slower growth, while in the second week, larvae fed with 1000 nauplii/post-larvae had the highest final weight and length. Regression analysis suggests that the optimum feeding density of Artemia nauplii during the first week is 411 nauplii/post-larvae, while for the second week, the growth increased proportionally to the feeding densities. The relative expression of the myod, myog, and mstn genes was higher in larvae fed with fewer than 500 nauplii/post-larvae. Although low-growing larvae showed increased expression of myod and myog genes, responsible for muscle hyperplasia and hypertrophy, respectively, mstn expression may have played a significant inhibitory role in larval development. Further research is needed to better determine the effects of the live food on the zootechnical performance and the expression of the myogenic genes in the initial phase of the life cycle of the tambaqui post-larvae.

Characterization of the zooplankton in the continental shelf of the Brazilian Equatorial Atlantic / Caracterização do zooplâncton na plataforma continental do atlântico equatorial brasileiro

The equatorial Atlantic is characterized by its high abundance of zooplankton. However, starting point studies concerning the species composition in the northern Brazilian continental shelf are still scarce. Species cataloging studies can help to know the diversity of this ecosystem and, consequently, de-velop conservation studies and strategies for natural resources management. Thus, this work aims to characterize the species composing the zooplanktonic communities present on the continental shelf of Maranhão. Ninety-six taxa distributed among the Radiolaria, Myozoa, Foraminifera, Cnidaria, Mollusca, Annelida, Arthropoda, Bryozoa, Chaetognatha, Echinodermata, Chordata, and other groups, were recorded. The composition of mesozooplankton showed a wide distribution, indicating that the species are finding the appropriate conditions for their development.(AU)

O Atlântico equatorial é caracterizado por sua alta abundância zooplanctônica, no entanto, estudos iniciais sobre a composição de espécies na plataforma continental do Norte do Brasil ainda são es-cassos. Pesquisas de catalogação de espécies podem auxiliar no conhecimento da diversidade desse ecossistema para, consequentemente, desenvolver estudos de conservação e estratégias para o manejo dos recursos naturais. Assim, este trabalho tem como objetivo caracterizar as espécies que compõem as comunidades zooplanctônicas presentes na plataforma continental do estado do Maranhão, localizada na porção equatorial do oceano Atlântico. A região apresentou 96 táxons distribuídos entre os grupos Radiolaria, Myxozoa, Foraminifera, Cnidaria, Mollusca, Annelida, Arthropoda, Bryozoa, Chaetognatha, Echinodermata, Chordata e outros. A composição do mesozooplâncton apresentou ampla distribuição, indicando que as espécies estão encontrando as condições adequadas para seu desenvolvimento.(AU)

Physiological and metabolic responses in juvenile Colossoma macropomum exposed to hypoxia.

This study aimed to evaluate hematological, biochemical, and gasometric parameters of tambaqui juveniles (Colossoma macropomum) exposed to hypoxia and subsequent recovery. Six animals were subjected to normoxia (basal) treatment with dissolved oxygen (DO) 6.27 ± 0.42 mg L-1. Water flow and aeration were reduced for 3 days (hypoxia), during which DO was 0.92 ± 0.37 mg L-1. Water flow and aeration were then reestablished with DO remaining similar to basal. The treatments were as follows: normoxia (basal); 24 h after initiating hypoxia (24H); 72 h after initiating hypoxia (72H); 24 h after reestablishing normoxia (24R); 48 h after reestablishing normoxia (48R); and 96 after reestablishing normoxia (96R). The highest glucose level was recorded at 24H (P < 0.05); the highest lactate level was at 72R; and the highest blood pH was at 24H and 72H (P < 0.05). The highest concentration of PvCO2 was at 24H (P < 0.05), while at 96R it was equivalent to basal (P > 0.05). The variable PvO2 was only higher than basal at 24R (P < 0.05). Juvenile C. macropomum managed to reestablish the main stress indicators (glucose and lactate) at 96R, while the other indicators varied during the study, with homeostatic physiology being reestablished during the recovery period.

Microphytoplankton dynamics in Curuperé Estuary at the amazonian mangrove ecosystem / Dinâmica do microfitoplâncton no estuário do Rio Curuperé em um ecossistema de manguezal amazônico

The aim of this study was to evaluate microphytoplankton dynamics and environmental parameters in the estuary of the Curuperé River, located in an Amazonian mangrove ecosystem. Ten sampling sites, where occupied to obtain surface water samples for qualitative and quantitative microphytoplankton analyses, chlorophyll-a, temperature, turbidity, salinity, and pH. Samplings were conducted in four months: in February, May, August and November/2015; the first two months corresponding to rainy season and the last two to dry season. Significant spatiotemporal differences were observed, for diversity, equitability and specific dominance of the microphytoplankton community. In total, 212 taxa were identified and this community was dominated by Bacillariophyta (149 taxa), followed by Myzozoa (29 taxa). The abundance varied from 7,700 ind L-1, (May, sampling site 1) to 343,800 ind L-1, in August (sampling site 4). The diatom Cymatosira belgica was the dominant species, followed by Dimeregramma minor (major peaks of 180,600 ind L-1 and 120,400 ind L-1, respectively) in August at point 4. Phytoplankton biomass indicates an eutrophic estuary as Chlorophyll-a varied from 13.01 to 112.88 mg m-3, probably due to marine shrimp farm effluents. It was possible to identify species strongly indicative of the environment, through analysis of indicator species (IndVal), and their relations with the...(AU)

O objetivo deste estudo foi avaliar a dinâmica microfitoplanctônica e os parâmetros ambientais no estuário do rio Curuperé, localizado em um ecossistema de manguezal na Amazônia. Foram realizados dez pontos de amostragem, utilizando amostras de água superficial para análises qualitativas (rede com malha de 20 µm) e quantitativa do microfitoplâncton, bem como para determinação de clorofila a, temperatura da água superficial, turbidez, salinidade e pH. As amostragens foram realizadas em quatro meses: fevereiro, maio, agosto e novembro, sendo os dois primeiros correspodentes ao período chuvoso e os dois últimos, ao seco. Foram observadas diferenças significativas entre os meses e relacionadas à posição ao longo do eixo estuarino para diversidade, eqüitabilidade e dominância específica na comunidade microfitoplanctônica. Foram identificados 212 com dominância de Bacillariophyta (149 taxa), seguido por Myzozoa (29 taxa). O microfitoplâncton variou de 7.700 ind L-1, (maio, ponto 1) a 343.800 ind L-1, em agosto (ponto 4). A diatomácea Cymatosira belgica foi a espécie dominante, seguida por Dimeregramma minor (maiores picos de 180.600 ind L-1 e 120.400 ind L-1, respectivamente) em agosto no ponto 4. Os valores de clorofila a permaneceram altos ao longo do ano variando de 13,01 a 112,88 mg m-3, provavelmente devido aos efluentes de fazenda de camarões marinhos. Foi possível identificar...(AU)

Microphytoplankton dynamics in Curuperé Estuary at the amazonian mangrove ecosystem / Dinâmica do microfitoplâncton no estuário do Rio Curuperé em um ecossistema de manguezal amazônico

The aim of this study was to evaluate microphytoplankton dynamics and environmental parameters in the estuary of the Curuperé River, located in an Amazonian mangrove ecosystem. Ten sampling sites, where occupied to obtain surface water samples for qualitative and quantitative microphytoplankton analyses, chlorophyll-a, temperature, turbidity, salinity, and pH. Samplings were conducted in four months: in February, May, August and November/2015; the first two months corresponding to rainy season and the last two to dry season. Significant spatiotemporal differences were observed, for diversity, equitability and specific dominance of the microphytoplankton community. In total, 212 taxa were identified and this community was dominated by Bacillariophyta (149 taxa), followed by Myzozoa (29 taxa). The abundance varied from 7,700 ind L-1, (May, sampling site 1) to 343,800 ind L-1, in August (sampling site 4). The diatom Cymatosira belgica was the dominant species, followed by Dimeregramma minor (major peaks of 180,600 ind L-1 and 120,400 ind L-1, respectively) in August at point 4. Phytoplankton biomass indicates an eutrophic estuary as Chlorophyll-a varied from 13.01 to 112.88 mg m-3, probably due to marine shrimp farm effluents. It was possible to identify species strongly indicative of the environment, through analysis of indicator species (IndVal), and their relations with the...

O objetivo deste estudo foi avaliar a dinâmica microfitoplanctônica e os parâmetros ambientais no estuário do rio Curuperé, localizado em um ecossistema de manguezal na Amazônia. Foram realizados dez pontos de amostragem, utilizando amostras de água superficial para análises qualitativas (rede com malha de 20 µm) e quantitativa do microfitoplâncton, bem como para determinação de clorofila a, temperatura da água superficial, turbidez, salinidade e pH. As amostragens foram realizadas em quatro meses: fevereiro, maio, agosto e novembro, sendo os dois primeiros correspodentes ao período chuvoso e os dois últimos, ao seco. Foram observadas diferenças significativas entre os meses e relacionadas à posição ao longo do eixo estuarino para diversidade, eqüitabilidade e dominância específica na comunidade microfitoplanctônica. Foram identificados 212 com dominância de Bacillariophyta (149 taxa), seguido por Myzozoa (29 taxa). O microfitoplâncton variou de 7.700 ind L-1, (maio, ponto 1) a 343.800 ind L-1, em agosto (ponto 4). A diatomácea Cymatosira belgica foi a espécie dominante, seguida por Dimeregramma minor (maiores picos de 180.600 ind L-1 e 120.400 ind L-1, respectivamente) em agosto no ponto 4. Os valores de clorofila a permaneceram altos ao longo do ano variando de 13,01 a 112,88 mg m-3, provavelmente devido aos efluentes de fazenda de camarões marinhos. Foi possível identificar...

Effectiveness of benzocaine as anesthetic at different water temperatures for early juvenile curimba (Prochilodus lineatus valenciennes, 1836), a neotropical fish species / Eficácia da benzocaina como anestésico em diferentes temperaturas de água para juvenis de curimba (Prochilodus lineatus valenciennes, 1836), uma espécie de peixe neotropical

Anesthetics have been used frequently in aquaculture to minimize stress during handling. However, several factors can affect the efficiency of anesthetics. For example, temperature is one of the abiotic factors that control animal metabolism and consequently, the effect of anesthetics. This study aimed to evaluate the effectiveness of benzocaine as an anesthetic for early juveniles of curimba Prochilodus lineatus at different water temperatures. Juveniles (4.7 ± 1.6 g and total length of 7.4 ± 0.7 cm) were submitted to anesthesia at concentrations of 30, 40, 50, 60, 70, and 80 mg L-1 of benzocaine and temperatures of 22, 25, 28, and 31 °C. The effects were evaluated by measuring the induction time to deep and surgical anesthesia, recovery time, time to appetite return, and 96-h mortality rate. The higher temperatures (25, 28 and 31°C) provided shorter induction times to reach deep anesthesia and at 50 mg L-1 of benzocaine, the induction time was between 2 and 3 min. Juveniles at temperatures of 28 and 31 °C showed lower surgical anesthesia induction time at concentrations ranging from 60 to 80 mg L-1. Recovery time was longer at 22 °C at all concentrations. The time to appetite return occurred in the first 24 h after anesthesia and the 96-h mortality rate was lower than 10%. Under these conditions, for deep anesthesia, benzocaine concentration of 50 mg L-1 for water temperatures of 25, 28, and 31 °C and 60 mg L-1 for 22 °C are recommended. Surgical anesthesia can be performed with 50 mg L-1 of benzocaine at all four water temperatures. The differences documented in the present study underline the need for adequate concentrations of anesthetics depending on the prevalent water temperature for Neotropical fish species. This should be considered in recommendations for large-scale use.(AU)

Os anestésicos têm sido usados com frequência na aquicultura para minimizar o estresse durante o manejo. Entretanto, vários fatores podem afetar a eficiência do anestésico. Por exemplo, a temperatura é um dos fatores abióticos que controlam o metabolismo animal e, consequentemente, os efeitos anestésicos. Este estudo teve como objetivo avaliar a eficácia da benzocaína como anestésico em juvenis de curimba Prochilodus lineatus em diferentes temperaturas da água. Juvenis (4,7 ± 1,6 g e comprimento total de 7,4 ± 0,7 cm) foram submetidos à anestesia nas concentrações de 30, 40, 50, 60, 70 e 80 mg de benzocaína L-1 e temperaturas de 22, 25, 28 e 31 °C. Os efeitos foram avaliados medindo-se o tempo de indução à anestesia profunda e cirúrgica, tempo de recuperação, tempo de retorno do apetite e taxa de mortalidade em 96 horas. As maiores temperaturas (25, 28 e 31 °C) proporcionaram menores tempos de indução a anestesia profunda e em 50 mg de benzocaína L-1 o tempo de indução foi entre 2 e 3 min. Juvenis nas temperaturas de 28 e 31 °C apresentaram menor tempo de indução a anestesia cirúrgica nas concentrações variando de 60 a 80 mg L-1. O tempo de recuperação foi superior a 22 ° C em todas as concentrações. O tempo de retorno do apetite ocorreu nas primeiras 24 horas após a anestesia e a taxa de mortalidade após 96 horas foi inferior a 10%. Nestas condições, para anestesia profunda, recomenda-se a concentração de 50 mg L-1 de benzocaína nas temperaturas de 25, 28 e 31 °C e 60 mg L-1 para 22 °C. A anestesia cirúrgica pode ser realizada com 50 mg de benzocaína L-1nas quatro temperaturas. As diferenças documentadas no presente estudo reforçam a necessidade de adequar a concentração do anestésico à temperatura da água para as espécies de peixes neotropicais, devendo ser reconsiderada na recomendação para uso em larga escala.(AU)

Effectiveness of benzocaine as anesthetic at different water temperatures for early juvenile curimba (Prochilodus lineatus valenciennes, 1836), a neotropical fish species / Eficácia da benzocaina como anestésico em diferentes temperaturas de água para juvenis de curimba (Prochilodus lineatus valenciennes, 1836), uma espécie de peixe neotropical

Anesthetics have been used frequently in aquaculture to minimize stress during handling. However, several factors can affect the efficiency of anesthetics. For example, temperature is one of the abiotic factors that control animal metabolism and consequently, the effect of anesthetics. This study aimed to evaluate the effectiveness of benzocaine as an anesthetic for early juveniles of curimba Prochilodus lineatus at different water temperatures. Juveniles (4.7 ± 1.6 g and total length of 7.4 ± 0.7 cm) were submitted to anesthesia at concentrations of 30, 40, 50, 60, 70, and 80 mg L-1 of benzocaine and temperatures of 22, 25, 28, and 31 °C. The effects were evaluated by measuring the induction time to deep and surgical anesthesia, recovery time, time to appetite return, and 96-h mortality rate. The higher temperatures (25, 28 and 31°C) provided shorter induction times to reach deep anesthesia and at 50 mg L-1 of benzocaine, the induction time was between 2 and 3 min. Juveniles at temperatures of 28 and 31 °C showed lower surgical anesthesia induction time at concentrations ranging from 60 to 80 mg L-1. Recovery time was longer at 22 °C at all concentrations. The time to appetite return occurred in the first 24 h after anesthesia and the 96-h mortality rate was lower than 10%. Under these conditions, for deep anesthesia, benzocaine concentration of 50 mg L-1 for water temperatures of 25, 28, and 31 °C and 60 mg L-1 for 22 °C are recommended. Surgical anesthesia can be performed with 50 mg L-1 of benzocaine at all four water temperatures. The differences documented in the present study underline the need for adequate concentrations of anesthetics depending on the prevalent water temperature for Neotropical fish species. This should be considered in recommendations for large-scale use.

Os anestésicos têm sido usados com frequência na aquicultura para minimizar o estresse durante o manejo. Entretanto, vários fatores podem afetar a eficiência do anestésico. Por exemplo, a temperatura é um dos fatores abióticos que controlam o metabolismo animal e, consequentemente, os efeitos anestésicos. Este estudo teve como objetivo avaliar a eficácia da benzocaína como anestésico em juvenis de curimba Prochilodus lineatus em diferentes temperaturas da água. Juvenis (4,7 ± 1,6 g e comprimento total de 7,4 ± 0,7 cm) foram submetidos à anestesia nas concentrações de 30, 40, 50, 60, 70 e 80 mg de benzocaína L-1 e temperaturas de 22, 25, 28 e 31 °C. Os efeitos foram avaliados medindo-se o tempo de indução à anestesia profunda e cirúrgica, tempo de recuperação, tempo de retorno do apetite e taxa de mortalidade em 96 horas. As maiores temperaturas (25, 28 e 31 °C) proporcionaram menores tempos de indução a anestesia profunda e em 50 mg de benzocaína L-1 o tempo de indução foi entre 2 e 3 min. Juvenis nas temperaturas de 28 e 31 °C apresentaram menor tempo de indução a anestesia cirúrgica nas concentrações variando de 60 a 80 mg L-1. O tempo de recuperação foi superior a 22 ° C em todas as concentrações. O tempo de retorno do apetite ocorreu nas primeiras 24 horas após a anestesia e a taxa de mortalidade após 96 horas foi inferior a 10%. Nestas condições, para anestesia profunda, recomenda-se a concentração de 50 mg L-1 de benzocaína nas temperaturas de 25, 28 e 31 °C e 60 mg L-1 para 22 °C. A anestesia cirúrgica pode ser realizada com 50 mg de benzocaína L-1nas quatro temperaturas. As diferenças documentadas no presente estudo reforçam a necessidade de adequar a concentração do anestésico à temperatura da água para as espécies de peixes neotropicais, devendo ser reconsiderada na recomendação para uso em larga escala.

Concentrações de metais pesados nos sedimentos do lago Água Preta (Pará, Brasil) / Concentration of heavy metals in Água Preta lake sediments (Pará, Brazil)

RESUMO O presente trabalho consistiu em avaliar as concentrações de nutrientes e metais pesados nos sedimentos do fundo do lago Água Preta, localizado na Região Metropolitana de Belém, Estado do Pará. As concentrações de metais pesados foram obtidas por espectrometria de emissão por plasma acoplado a espectrometria de massas (ICP-MS). Os metais que apresentaram maior concentração foram o cromo (245 mg.Kg-1) e o níquel (97 mg.Kg-1), os quais estiveram acima do índice que determina o nível de efeito provável (Probable Effect Level - PEL). O trabalho evidenciou o reflexo das pressões antrópicas que o lago Água Preta vem sofrendo ao longo dos anos, mostrando que os sedimentos de fundo se encontram impactados por metais pesados, altas cargas de matéria orgânica e nutrientes.

ABSTRACT The present study evaluated the concentrations of nutrients and heavy metals in bottom sediments of Água Preta lake, located in the metropolitan region of Belém, Pará state, Brazil. Concentrations of heavy metals were obtained by emission spectrometry with inductively coupled plasma mass spectrometry (ICP-MS). Metals that showed high concentrations were chromium (245 mg.Kg-1) and nickel (97 mg.Kg-1), both above Propable Effect Level (PEL) index. The work revealed the reflection of the anthropogenic pressures that Água Preta lake has suffered over the years, showing that the bottom sediments are impacted by heavy metals, high loads of organic matter and nutrients.

Zooplankton From a Reef System Under the Influence of the Amazon River Plume.

At the mouth of the Amazon River, a widespread carbonate ecosystem exists below the river plume, generating a hard-bottom reef (∼9500 km2) that includes mainly large sponges but also rhodolith beds. The mesozooplankton associated with the pelagic realm over the reef formation was characterized, considering the estuarine plume and oceanic influence. Vertical hauls were carried out using a standard plankton net with 200 µm mesh size during September 2014. An indicator index was applied to express species importance as ecological indicators in community. Information on functional traits was gathered for the most abundant copepod species. Overall, 179 zooplankton taxa were recorded. Copepods were the richest (92 species), most diverse and most abundant group, whereas meroplankton were rare and less abundant. Species diversity (>3.0 bits.ind-1) and evenness (>0.6) were high, indicating a complex community. Small holoplanktonic species dominated the zooplankton, and the total density varied from 107.98 ind. m-3 over the reef area to 2,609.24 ind. m-3 in the estuarine plume, with a significant difference between coastal and oceanic areas. The most abundant copepods were the coastal species ithona plumifera and Clausocalanus furcatus and early stages copepodites of Paracalanidae. The holoplanktonic Oikopleura, an important producer of mucous houses, was very abundant on the reefs. The indicator species index revealed three groups: (1) indicative of coastal waters under the influence of the estuarine plume [Euterpina acutifrons, Parvocalanus crassirostris, Oikopleura (Vexillaria) dioica and Hydromedusae]; (2) characterized coastal and oceanic conditions (Clausocalanus); (3) characterized the reef system (O. plumifera). Two major copepods functional groups were identified and sorted according to their trophic strategy and coastal-oceanic distribution. The species that dominated the coastal area and the area over the rhodolith beds are indicators of the estuarine plume and are mixed with species of the North Brazil Current. These species practically disappear offshore, where occur oceanic species commonly found in other oligotrophic tropical areas. This ecosystem shows a mixture of estuarine, coastal and oceanic communities coexisting in the waters over the Amazon reefs, with no significant differences among these areas. However, the MDS clearly separated the communities along the salinity gradient in the plume.

Diversidad y biomasa de fitoplancton en el cultivo de camarón marino del estado de Pará / Diversity and biomass phytoplankton in marine shrimp farming in Para state / Diversidade e biomassa fitoplanctônica em viveiro de carcinicultura marinha no estado do Pará

Este estudio evaluó durante un ciclo de cultivo de Litopenaeus vannamei la comunidad de fitoplancton y los parámetros abióticos en dos estaciones dentro de un cuarto de niños en Curuçá (PA), el norte de Brasil. Se midieron la transparencia, pH, oxígeno disuelto, la salinidad y la temperatura. Teniendo en cuenta los últimos cuatro parámetros se registraron en la superficie del agua y cerca del fondo. Además, también se recogieron muestras para estudiar la concentración fiitoplâncton y clorofila "a". La temperatura varió desde 31,5 hasta 35 ° C; Oxígeno disuelto 4,2-15,5 mg / L; pH entre 8,1 y 9,4; la salinidad de 26.9 a 30 ppm. Transparencia redujo de 55 a 17 cm. La clorofila varió desde 2,33 hasta 471,34 mg / m3. En cuanto al análisis de fitoplancton se identificaron 95 tasa Bacillariofitas y fue el grupo más representativo, con predominio de Navivcula sp sp Pleurosigma y Nitzschia sp. La densidad más alta registrada fue de 104.400 y el más bajo fue de 3.600 org / L. La diversidad promedio enla estación 01 era de 1,49 bits / ind y de la estación 02, 1,43 bits / ind. Se concluyó que: la división Bacillariophyta era el grupo más importante (riqueza y densidad); Dinophyceae la clase resultó ser el más adecuado en las aguas más claras; Los valores de clorofila "a" tenían una relación directa con la alimentación artificial, aumentando con el tiempo; A pesar de las grandes fluctuaciones de parámetros abióticos tales como el pH, el oxígeno disuelto y la transparencia, sistema de cultivo se consideró homogénea.(AU)

This work aimed to evaluate the the phytoplanktonic community and the abiotic parameters during a cycle of cultivation of Litopenaeus vannamei in two stations in a pond in Curuçá (PA), northern Brazil. Were measured transparency, pH, dissolved oxygen, salinity and temperature. Considering the last four parameters, were registered in the surface water and the bottom set. Additionally, also were collected samples to study the fitoplankton and chlorophyll “a” concentrations. The temperature values were between 31,5 and 35 ºC; dissolved oxygen concentrations were between 4,2 and 15,5 mg/L; pH between 8,1 and 9,4; salinity from 26,9 to 30 ppm. The transparency decreased from 55 to 17 cm. The Chlorophyll a concentrations were from 2,33 to 471,34 mg/m3. The transparency decreased of 55 to 17 cm. Chlorophyll a from 2,33 to 471,34 mg/m3. Regarding the fitoplankton analyses, were identified 95 taxa and Bacillariophyta was the most representative group, with dominance of the Navicula sp, Pleurosigma sp and Nitzschia sp. The largest density registered was of 104.400 and to smallest was 3.600 org/L. The mean diversity at the station 01 was 1,49 bits/ind and in the station 02 was 1,43 bits/ind. Enter the main conclusions: the fitoplanktonic community was dominated by the diatom and the division Bacillariophyta was the most important group (wealth and density); the class dinophyceae revealed to be better adapted in the clearer waters; Chlorophyll “a” values presented a direct relationship to the feeding artificial, increasing with the time. Despite the great fluctuation of abiotic parameters such pH, dissolved oxygen and transparency, the cultivation system was considered homogeneous.(AU)

Este trabalho objetivou avaliar durante um ciclo de cultivo de Litopenaeus vannameia comunidade fitoplanctônica e parâmetros abióticos em duas estações dentro de um viveiro em Curuçá (PA), norte do Brasil. Foram medidos transparência, pH, oxigênio dissolvido, salinidade e temperatura. Considerando os últimos quatro parâmetros, foram registrados na água de superfície e próximo ao fundo. Além disso, também foram coletadas amostras para estudar o fiitoplâncton e concentrações de clorofila "a". A temperatura variou de 31,5 a 35 ºC; oxigênio dissolvido de 4,2 a 15,5 mg/L; pH entre 8,1 e 9,4; salinidade de 26,9 a 30 ppm. A transparência diminuiu de 55 para 17 cm. Clorofila a variou de 2,33 a 471,34 mg/m3. Em relação à análise do fitoplâncton, foram identificados 95 taxa e Bacillariophyta foi o grupo mais representativo, com dominância do Navicula sp, Pleurosigma sp e Nitzschia sp. A maior densidade registrada foi de 104.400 e a menor foi 3.600 org/L. A diversidade média na Estação 01 foi 1,49 bits/ind e na Estação 02, 1,43 bits/ind. Concluiu-se que: a divisão Bacillariophyta foi o grupo mais importante (riqueza e densidade); a classe dinophyceae revelou estar melhor adaptada em águas mais claras; Os valores de Clorofila “a” apresentaram uma relação direta com a alimentação artificial, aumentando com o tempo; Apesar da grande flutuação dos parâmetros abióticos como pH, oxigênio dissolvido e transparência, o sistema de cultivo foi considerado homogêneo.(AU)

Diversidad y biomasa de fitoplancton en el cultivo de camarón marino del estado de Pará / Diversity and biomass phytoplankton in marine shrimp farming in Para state / Diversidade e biomassa fitoplanctônica em viveiro de carcinicultura marinha no estado do Pará

Este estudio evaluó durante un ciclo de cultivo de Litopenaeus vannamei la comunidad de fitoplancton y los parámetros abióticos en dos estaciones dentro de un cuarto de niños en Curuçá (PA), el norte de Brasil. Se midieron la transparencia, pH, oxígeno disuelto, la salinidad y la temperatura. Teniendo en cuenta los últimos cuatro parámetros se registraron en la superficie del agua y cerca del fondo. Además, también se recogieron muestras para estudiar la concentración fiitoplâncton y clorofila "a". La temperatura varió desde 31,5 hasta 35 ° C; Oxígeno disuelto 4,2-15,5 mg / L; pH entre 8,1 y 9,4; la salinidad de 26.9 a 30 ppm. Transparencia redujo de 55 a 17 cm. La clorofila varió desde 2,33 hasta 471,34 mg / m3. En cuanto al análisis de fitoplancton se identificaron 95 tasa Bacillariofitas y fue el grupo más representativo, con predominio de Navivcula sp sp Pleurosigma y Nitzschia sp. La densidad más alta registrada fue de 104.400 y el más bajo fue de 3.600 org / L. La diversidad promedio enla estación 01 era de 1,49 bits / ind y de la estación 02, 1,43 bits / ind. Se concluyó que: la división Bacillariophyta era el grupo más importante (riqueza y densidad); Dinophyceae la clase resultó ser el más adecuado en las aguas más claras; Los valores de clorofila "a" tenían una relación directa con la alimentación artificial, aumentando con el tiempo; A pesar de las grandes fluctuaciones de parámetros abióticos tales como el pH, el oxígeno disuelto y la transparencia, sistema de cultivo se consideró homogénea.

This work aimed to evaluate the the phytoplanktonic community and the abiotic parameters during a cycle of cultivation of Litopenaeus vannamei in two stations in a pond in Curuçá (PA), northern Brazil. Were measured transparency, pH, dissolved oxygen, salinity and temperature. Considering the last four parameters, were registered in the surface water and the bottom set. Additionally, also were collected samples to study the fitoplankton and chlorophyll “a” concentrations. The temperature values were between 31,5 and 35 ºC; dissolved oxygen concentrations were between 4,2 and 15,5 mg/L; pH between 8,1 and 9,4; salinity from 26,9 to 30 ppm. The transparency decreased from 55 to 17 cm. The Chlorophyll a concentrations were from 2,33 to 471,34 mg/m3. The transparency decreased of 55 to 17 cm. Chlorophyll a from 2,33 to 471,34 mg/m3. Regarding the fitoplankton analyses, were identified 95 taxa and Bacillariophyta was the most representative group, with dominance of the Navicula sp, Pleurosigma sp and Nitzschia sp. The largest density registered was of 104.400 and to smallest was 3.600 org/L. The mean diversity at the station 01 was 1,49 bits/ind and in the station 02 was 1,43 bits/ind. Enter the main conclusions: the fitoplanktonic community was dominated by the diatom and the division Bacillariophyta was the most important group (wealth and density); the class dinophyceae revealed to be better adapted in the clearer waters; Chlorophyll “a” values presented a direct relationship to the feeding artificial, increasing with the time. Despite the great fluctuation of abiotic parameters such pH, dissolved oxygen and transparency, the cultivation system was considered homogeneous.

Este trabalho objetivou avaliar durante um ciclo de cultivo de Litopenaeus vannameia comunidade fitoplanctônica e parâmetros abióticos em duas estações dentro de um viveiro em Curuçá (PA), norte do Brasil. Foram medidos transparência, pH, oxigênio dissolvido, salinidade e temperatura. Considerando os últimos quatro parâmetros, foram registrados na água de superfície e próximo ao fundo. Além disso, também foram coletadas amostras para estudar o fiitoplâncton e concentrações de clorofila "a". A temperatura variou de 31,5 a 35 ºC; oxigênio dissolvido de 4,2 a 15,5 mg/L; pH entre 8,1 e 9,4; salinidade de 26,9 a 30 ppm. A transparência diminuiu de 55 para 17 cm. Clorofila a variou de 2,33 a 471,34 mg/m3. Em relação à análise do fitoplâncton, foram identificados 95 taxa e Bacillariophyta foi o grupo mais representativo, com dominância do Navicula sp, Pleurosigma sp e Nitzschia sp. A maior densidade registrada foi de 104.400 e a menor foi 3.600 org/L. A diversidade média na Estação 01 foi 1,49 bits/ind e na Estação 02, 1,43 bits/ind. Concluiu-se que: a divisão Bacillariophyta foi o grupo mais importante (riqueza e densidade); a classe dinophyceae revelou estar melhor adaptada em águas mais claras; Os valores de Clorofila “a” apresentaram uma relação direta com a alimentação artificial, aumentando com o tempo; Apesar da grande flutuação dos parâmetros abióticos como pH, oxigênio dissolvido e transparência, o sistema de cultivo foi considerado homogêneo.

Menthol and eugenol as natural anesthetics for early juveniles of curimba

The objective of this study was to evaluate menthol and eugenol as anesthetics for early juveniles of curimba, Prochilodus lineatus. Juveniles of 4.0±0.5 g and a total length of 8.8±0.1 cm were exposed to the anesthetics menthol (20, 30, 40, 50, 60, 70, and 80 mg L−1) and eugenol (20, 30, 40, 50, 60, and 70 mg L−1) up to deep anesthesia. The anesthetic effects were evaluated measuring the induction time to deep anesthesia (characterized by loss of equilibrium, absence of swimming, reduction of opercular movements, and responses only to intense tactile stimuli), recovery time, time to appetite return, and mortality rate after 96 h of procedure. The concentrations between 60 to 80 mg of menthol L−1 provided the lowest time of induction. Increased concentrations led to a decrease in recuperation time. The concentrations between 50 to 70 mg of eugenol L−1 provided the lowest induction times; however, recovery time was not affected by eugenol concentrations. The return to appetite was observed 24 h after anesthesia, while the survival after 96 h was >90%. Concentrations of 60 and 50 mg L−1 of menthol and eugenol, respectively, are recommended for effective anesthesia with limited side effects.(AU)

High genetic diversity and connectivity in Colossoma macropomum in the Amazon basin revealed by microsatellite markers

Abstract Colossoma macropomum is the second largest scaled fish of the Amazon. It is economically important for commercial fisheries and for aquaculture, but few studies have examined the diversity and genetic structure of natural populations of this species. The aim of this study was to investigate the levels of genetic variability and connectivity that exist between three natural populations of C. macropomum from the Amazon basin. In total, 247 samples were collected from the municipalities of Tefé, Manaus, and Santarém. The populations were genotyped using a panel of 12 multiplex microsatellite markers. The genetic diversity found in these populations was high and similar to other populations described in the literature. These populations showed a pattern of high gene flow associated with the lack of a genetic structure pattern, indicating that the number of migrants per generation and recent migration rates are high. The values of the FST, RST, and exact test of differentiation were not significant for pairwise comparisons between populations. The Bayesian population clustering analysis indicated a single population. Thus, the data provide evidence for high genetic diversity and high gene flow among C. macropomum populations in the investigated region of the Amazon basin. This information is important for programs aiming at the conservation of natural populations.

High genetic diversity and connectivity in Colossoma macropomum in the Amazon basin revealed by microsatellite markers.

Colossoma macropomum is the second largest scaled fish of the Amazon. It is economically important for commercial fisheries and for aquaculture, but few studies have examined the diversity and genetic structure of natural populations of this species. The aim of this study was to investigate the levels of genetic variability and connectivity that exist between three natural populations of C. macropomum from the Amazon basin. In total, 247 samples were collected from the municipalities of Tefé, Manaus, and Santarém. The populations were genotyped using a panel of 12 multiplex microsatellite markers. The genetic diversity found in these populations was high and similar to other populations described in the literature. These populations showed a pattern of high gene flow associated with the lack of a genetic structure pattern, indicating that the number of migrants per generation and recent migration rates are high. The values of the FST, RST, and exact test of differentiation were not significant for pairwise comparisons between populations. The Bayesian population clustering analysis indicated a single population. Thus, the data provide evidence for high genetic diversity and high gene flow among C. macropomum populations in the investigated region of the Amazon basin. This information is important for programs aiming at the conservation of natural populations.

First occurrence of Dolicholagus longirostris larvae (Maul 1948) (Osmeriformes, Bathylagidae) near the mouth of the Amazon River / Primeira ocorrência de larvas de Dolicholagus longirostris (Maul 1948) (Osmeriformes, Bathylagidae) próximas à foz do rio Amazona

The family Bathylagidae contains eight genera and 22 species, of which only five occur in the Southwest Atlantic. Until recently, only adult specimens of the bathylaginin Melanolagus bericoides had been recorded off southern Brazil, between the Santa Marta Cape and Rio Grande (31º S and 49º W). The present work reports the first occurrence of Dolicholagus longirostris larvae on the northern Brazilian coast, expanding its distribution in the Southwest Atlantic. The two specimens found were collected near the mouth of the Amazon River (02º 00' 19" N, 47º 03' 30" W, and 00º 49' 06" N, 46º 25' 09" W).

A família Bathylagidae apresenta oito gêneros e 22 espécies, sendo que apenas cinco destas espécies ocorrem no Atlântico Sudoeste. No sul do Brasil já havia sido registrada a ocorrência de exemplares adultos de Melanolagus bericoides entre o Cabo de Santa Marta e Rio Grande (31º S e 49º W). Este trabalho registra a primeira ocorrência de larvas de Dolicholagus longirostris na costa norte brasileira, ampliando sua distribuição no Atlântico Sudoeste. Os dois exemplares encontrados foram coletados na foz do Rio Amazonas (02º 00' 19" N, 47º 03' 30" W, e 00º 49' 06" N, 46º 25' 09" W).