Treinamento em reprodução de peixes: uma troca de experiências com piscicultores / Fish reproduction training: an exchange of experiences with fishers

 O estado do Pará apresenta elevado potencial aquícola pela abundância de recursos hídricos e pela quantidade de espécies nativas de interesse econômico para piscicultura. Entretanto, apesar desse potencial, a produção aquícola não desponta em relação aos outros estados da região Norte. Percebe-se que a informação sobre técnicas de manejo e cuidados em diversos processos na criação de peixes é considerada baixa para os piscicultores da região, principalmente no que se refere sobre a reprodução. Por isso, o objetivo deste trabalho é apresentar as práticas de continuas sobre o processo de capacitação de discentes e piscicultores referentes a reprodução de peixes visando a transferência de tecnologia para escala produtiva local, aprimorar   material didático e promover a interação do discente com os piscicultores, através da troca de informações e uso de técnicas em reprodução. Durante o primeiro período de desenvolvimento deste trabalho, foi realizado um levantamento bibliográfico sobre a temática, para embasar o desenvolvimento das atividades práticas de reprodução. E essas práticas foram realizadas em parceria com o LAMPOA-UFOPA e UAGRO- Santa Rosa –SEDAP- Santarém-PA. No decorrer do estudo foi realizado a coleta de matrizes, observando-se o manejo correto de seleção dos reprodutores, processo técnico de indução hormonal e extrusão. Com os conhecimentos obtidos durante a capacitação, realizou-se uma roda de conversa, um minicurso e a produção de um folder com informações sobre técnicas de reprodução de peixes, onde foi repassado para os piscicultores no III Encontro para Produtores sobre Técnicas Alternativas em Aquicultura (EPAQUI), realizado na Cidade de Monte Alegre nos dias 16 e 17 de agosto de 2019. Este evento é idealizado pelo grupo de pesquisa Aquicultura no Baixo Amazonas e pelo Projeto de Extensão Multiplicadores em Aquicultura na Região Oeste do Pará, que ocorre anualmente visando a integração da academia junto a sociedade, de forma a contribuir com o desenvolvimento da piscicultura na região. A transferência de técnicas de reprodução para os piscicultores pode vir a ser um dos elos mais rentáveis na piscicultura além da integração necessária da academia e o setor produtivo, pois quando capacitado tecnicamente o piscicultor poderá reconhecer os caminhos para gerar a demanda por alevinos com boa qualidade, garantindo assim maior crescimento e produção no setor aquícola da região Oeste do Pará.

DESCRIÇÃO MORFOLÓGICA DO DESENVOLVIMENTO INICIAL DE Brycon amazonicus (CHARACIFORMES, BRYCONIDAE) DO BAIXO AMAZONAS, PARÁ

The present study characterized the initial development of matrinxã Brycon amazonicus (Agassiz, 1829), as well as the changes in allometric growth patterns during the initial ontogeny of the species. A total of 260 laravae from induced reproduction were analyzed for morphometric and meristic variables, as well as the coeffient of allometric growth in relation to head and body length. The initial larvae (3.9 to 5.9 mm) of B. amazonicus are transparent and have a relatively large and elongated yolk sac. In the pre-flexion stage (5,9 to 7,6 mm) the larvae presented dendritic pigmentation in the upper region of the head and pointed along the upper region of the swimming bladder. At the flexion (8,3 to 13,5 mm) and post-flexion (15 to 26 mm), pigmentation intensifies with pigments (dendrict and punctiform) distributing mainly in the upper region of the head, lateral dorsum of the body and along the lateral line.Keywords: Initial development; morphology; negative allometry; fish; matrinxã.O presente estudo caracterizou o desenvolvimento inicial do matrinxã, Brycon amazonicus (Agassiz, 1829), bem como as mudanças nos padrões de crescimento alométrico durante a ontogenia inicial da espécie. Um total de 260 larvas provenientes de reprodução induzida foram analisados quanto as variáveis morfométricas e merísticas, além do coeficiente de crescimento alométrico em relação ao comprimento da cabeça e do corpo. As larvas iniciais (3,9 a 5,9 mm) de B. amazonicus apresentam-se transparentes e com saco vitelínico relativamente grande e alongado. No estágio de pré-flexão (5,9 a 7,6 mm) as larvas apresentaram pigmentação dendrítica na região superior da cabeça e puntiformes ao longo da região superior da bexiga natatória. Nos estágios de flexão (8,3 a 13,5 mm) e pós-flexão (15 a 26 mm), a pigmentação se intensifica com pigmentos (dendríticos e puntiformes) distribuindo-se principalmente na região superior da cabeça, dorso lateral do corpo e ao longo da linha lateral.Palavras-chave: Alometria negativa; desenvolvimento inicial; morfologia; peixe; matrinxã

A social and ecological assessment of tropical land uses at multiple scales: the Sustainable Amazon Network

Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazonia Sustentavel, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far.Keywords: Social–ecological systems, Tropical forests, Land use, Interdisciplinary research, Sustainability, Trade-off

Growth and survival of silver catfish larvae, Rhamdia quelen (Heptapteridae), at different calcium and magnesium concentrations

Since the relative ratios of Ca2+ and Mg2+ can vary greatly from one water body to another, and lime used for the increase of water hardness or pH can have different ratios of Ca2+ and Mg2+ in its composition, the objective of this study was to analyze the growth and survival of silver catfish, Rhamdia quelen, larvae at different calcium and magnesium concentrations. After fertilization, eggs were randomly divided into 4 treatments (three replicates per treatment) with different concentrations of Ca2+ and Mg2+ at hardness values of 70 mg.L-1 CaCO3 (mg.L-1 : 5.2 Ca2+ and 14.12 Mg2+; 13.11 Ca2+ and 7.11 Mg2+; 20.26 Ca2+ and 2.86 Mg2+; 24.95 Ca2+ and 0.95 Mg2+) and 150 mg.L-1 CaCO3 (mg.L-1 : 5.2 Ca2+ and 32.70 Mg2+; 28.63 Ca2+ and 16.44 Mg2+; 44.68 Ca2+and 6.44 Mg2+; 62.78 Ca2+ and 0.95 Mg2+). There was also another group exposed to water hardness of 20 mg.L-1 CaCO3 (Ca2+ 5.2 mg.L-1 and Mg2+ 0.95 mg.L-1) at both experiments. The post-hatch larvae were transferred to continuously aerated 40 L polyethylene aquaria (400 larvae/tank) containing the same water as used for incubation. Samples of larvae were collected on days 0, 7, 14, and 21, and the length, weight, and specific growth rate were determined for each collection. Survival and biomass were calculated on day 21. At water hardness of 70 mg.L-1 CaCO3, the best survival and growth of silver catfish larvae was observed at water with 20.26 mg.L-1 Ca2+ and 2.89 mg.L-1 Mg2+, with similar results to the group exposed to water hardness of 20 mg.L-1 CaCO3. However, compared to the group exposed to water hardness of 20 mg.L-1 CaCO3, survival and growth were lower at 150 mg.L-1 CaCO3. Therefore, a hardness range of 20 to 70 mg.L-1 CaCO3 is recommended for silver catfish larviculture, but with 20.26 mg.L-1 Ca2+ and 2.89 mg.L-1 Mg2+ at 70 mg.L-1 CaCO3. Water hardness of 150 mg.L-1 CaCO3 is not recommended for this species

Anesthesia and sedation of map treefrog (Hypsiboas geographicus) tadpoles with essential oils

ABSTRACT: The goal of this study was to investigate the sedative and anesthetic properties of essential oils (EOs) in map treefrog tadpoles (Hypsiboas geographicus) and to determine the sedation and deep anesthesia induction times as well as the recovery time. The tadpoles were exposed to one of the EOs from three plant species: Aniba rosaeodora (EOAR - 25, 50, 100 or 200µL L-1), Lippia origanoides (EOLO - 13, 25, 50, 100 or 200µL L-1), and Lippia alba (either chemotype citral [EOL-C - 25, 50, 100 or 200µL L-1] or linalool [EOL-L - 50, 75, 100 or 200µL L-1]) (n = 8 per replicate). The tadpoles exposed to 25 and 50µL L-1 EOL-C and EOL-L, respectively, were not anesthetized within 30min (the maximum time of observation), and those exposed to 200µL L-1 EOLO did not recover within 30min. Sedation, deep anesthesia and recovery times showed a concentration-dependent relationship for all EOs tested, with the exception of the recovery with EOLO. The results allowed concluding that all investigated EOs can be used to anesthetize tadpoles of H. geographicus, but the use of EOLO must not exceed 100µL L-1

A social and ecological assessment of tropical land uses at multiple scales:the Sustainable Amazon Network

Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazonia Sustentavel, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far