Diante da constante degradação dos ecossistemas fluviais torna-se de fundamental importância o desenvolvimento de métodos que avaliem os padrões globais que determinam a qualidade dos sistemas lóticos de forma objetiva, com baixo custo e de maneira eficiente. Assim, o objetivo desse trabalho foi analisar a eficiência da utilização de um Protocolo de Avaliação Rápida da Diversidade de Habitat em atividades de monitoramento de ambientes lóticos por estudantes de graduação. O estudo foi conduzido em dois riachos e contou com a participação de 114 estudantes dos cursos de bacharelado em Ciências Biológicas e Engenharia Ambiental, que utilizaram o protocolo adaptado dos propostos pela EPA de Ohio, EUA. Na avaliação, os riachos Curral de Arame e Água Boa foram classificados em “natural” e “alterado”, respectivamente. Observou-se baixa variabilidade nas respostas entre os estudantes, o que não interferiu no resultado final da avaliação das condições ecológicas dos riachos. Alguns dos parâmetros físicos e químicos da água mensurados corroboram a classificação do protocolo, uma vez que foi observada diferença significativa para oxigênio dissolvido e condutividade elétrica da água entre os riachos. Entretanto, o protocolo utilizado constituiu-se em um eficiente recurso didático e uma ferramenta simples e dinâmica para atividades de monitoramento.

Fish farming is becoming an increasingly popular agricultural activity, and water quality in these environments is a major concern. Fish parasites, such as monogeneans, respond to changes in abiotic conditions, either with an increase or decrease in population. This study aimed to identify gill monogeneans and analyse their relationships with abiotic factors during the ontogenetic development of Nile tilapia over the fish culture cycle in Mato Grosso do Sul, Brazil. Fish were sampled monthly for eight months, and a total of 200 fish were collected. The physical and chemical water parameters were measured and correlated with the abundance of each monogenean species. Over the fish culture cycle, the physical and chemical parameters fluctuated, and the water quality decreased. The parasites found included Cichlidogyrus tilapiae, Cichlidogyrus thurstonae, Cichlidogyrus sclerosus, Cichlidogyrus halli and Scutogyrus longicornis. The abundances of all species showed significant differences during ontogenetic development (body size) and C. tilapiae, C. sclerosus, C. thurstonae and S. longicornis were correlated with changes in abiotic conditions. However, C. halli was not significantly correlated with any of the evaluated physical or chemical parameters. Understanding how different monogenean species respond to changes in the physical and chemical parameters of water during a production cycle can prevent peaks in abundance and subsequent sanitary problems.

ABSTRACT. We evaluated the growth and diet composition of hybrid surubim larvae (Pseudoplatystoma corruscans x P. reticulatum) produced in two fish farming by using different systems of feeding with natural plankton: M I, larvae are transferred to fertilized fish pond for being freely fed with natural plankton; M II, larvae are remained inside laboratory in glass fiber boxes and plankton are gathered with a plankton net and offered in a controlled way. It was collected 10 individuals daily during the feeding period with live plankton for 20 days. After the biometry, stomachs were opened and the food items identified and quantified by the volumetric method. The items were represented by algae, protozoa, microcrustacean, insect larvae and surubim fragments (cannibalism). The items with higher volumetric percentage were Chironomidae larvae (29.25%) followed by surubim fragments (19.68%) in M I, and surubim fragments (21.85%) and Moina micrura (19.97%) in MII. The items Chydorus sp., Diaphanosoma sp., sp. Macrothrix and Ephemeroptera larvae were found only in fish of M I, while algae Ulothrix sp., Oscillatoria sp. and the protozoa Difflugia sp were only found in stomachs of surubim from M II. Regarding the growth, the surubim had grown faster in M I.Keywords: larviculture, freshwater fish, diet.Alimentação de larvas do surubim híbrido Pseudoplatystoma sp. sob duas condições de manejo alimentar RESUMO. Este trabalho avaliou o crescimento e a composição da dieta de larvas do surubim híbrido (Pseudoplatystoma corruscans x P. reticulatum) produzidas em duas pisciculturas que utilizam sistemas diferentes de alimentação com plâncton natural: M I, as larvas são transferidas para viveiros previamente fertilizados para se alimentarem livremente com plâncton natural e M II, as larvas permanecem no laboratório em caixas de fibra de vidro e o plâncton são coletados com rede e oferecidos de forma controlada. Foram coletados dez exemplares por dia durante 20 dias. Após a biometria e a retirada dos estômagos, os itens alimentares foram identificados e quantificados por meio do método volumétrico. Os itens com maiores percentuais volumétricos foram larvas de Chironomidae (29,25%) seguido de restos de surubim (19,68%) em M I e restos de surubim (21,85%) e Moina micrura (19,97%) em M II. Os itens Chidorus sp., Diaphanosoma sp., Macrotrix SP. e larvas de Ephemeroptera foram encontrados apenas nos estômagos dos surubins do M I, enquanto as algas Ulothrix sp., Oscillatoria sp., assim como o protozoário do gênero Diflugia, foram observados apenas nos estômagos dos surubins do M II. Em relação ao crescimento, os surubins do M I apresentaram crescimento mais rápido do que em M II.Palavras-chave: larvicultura, peixe de água doce, dieta.

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The presence of interspecific hybrid surubim (Pseudoplatystoma corruscans × Pseudoplatystoma reticulatum) in natural environments can put at risk the existence of the pure parental lineages. The aim of this study was to characterize the genetic variability of pure Pseudoplatystoma corruscans and Pseudoplatystoma reticulatum individuals from rivers in the Paraná and Paraguay basins in Brazil. Seventy-six pure individuals of P. corruscans and 16 of P. reticulatum were evaluated with six microsatellite loci for both species, along with one species-specific locus each for P. corruscans and P. reticulatum. Loss of heterozygosity was confirmed, and preservation measures for P. corruscans and P. reticulatum are needed in order not to lose further genetic variation. In addition, we confirmed that these markers are useful for the management of pure stocks in natural environments, for fish breeding, and in Biology Electronic supplementary material The online version of this article (

A piscicultura no Mato Grosso do Sul é considerada recente se comparada a outras atividades agropecuárias. Os piscicultores do Estado têm um histórico de pioneirismo na piscicultura brasileira, tendo sido responsáveis pela produção comercial de várias espécies nativas. Considerando que mais de 90% dos piscicultores da região são considerados pequenos produtores, e que a maioria deles atua sem a devida regularização ambiental, o objetivo deste trabalho foi diagnosticar os principais entraves que o pequeno produtor de pescado da região da Grande Dourados (MS) encontra para a regularização ambiental, assim como conhecer o perfil dessas pequenas propriedades, no intuito de buscar subsídios para ações que minimizem a informalidade na produção de pescado. De acordo com os resultados, os principais problemas dos piscicultores em buscar a regularização ambiental estão relacionados à falta de informação. No entanto, notou-se que os produtores tem interesse em regularizar a atividade para obter incentivos fiscais e poder investir na melhoria e expansão da piscicultura. PALAVRAS-CHAVE:Legislação Ambiental; Impacto Ambiental; Piscicultura; Micro Empreendimento. ENVIRONMENTAL LICENCING IN FISH FARMING SMALL PROPERTIES EMPHASIS: TOOLS FOR ENVIRONMENTAL MANAGEMENT ABSTRACTFish farming in Mato Grosso do Sul (Brazil) is recent if compared to other agricultural activities. Farmers of the State have a history of pioneering in aquaculture, has been responsibles for the commercial production of several native species. Whereas more than 90% of fish farmers in the region are considered small producers, and most of them working without proper environmental regulation, the aim was to diagnose the main obstacles to obtaining the environmental permit in small property and use this data as a tool for the definition of methodologies for environmental management that minimize environmental impacts and informality in fish production on Grande Dourados region. According to the survey results, the main problems of fish farmers visited in seeking environmental regulation is related to lack of information. However, it was noted that producers have an interest in regulating the activity and for tax incentives to invest in the improvement and expansion of fish farming.

The fish farms state of Mato Grosso do Sul (Brazil) have been facing commercialization problems of the Patinga (Piaractus mesopotamicus (Holmberg, 1887) × Piaractus brachypomus (Cuvier, 1818)) due to hight acanthocephalans infection. The aim of this study was to identify the acanthocephalan species that infect this hybrid and assess the influence of management practices on the intensity of the parasite in fish farms. Samples were collected between October 2017 and June 2018. The transparency was the only water quality parameter that differed among the fish farms, and the values were below the limit established for fish production. Echinorhynchus gomesi was recorded in fish farms A, B and C. There was no significant correlation between the intensity of E. gomesi infections and the length of the intestine, and the standard length of the fish. The intensity of E. gomesi also did not affect the condition of the fish. The results of the study demonstrated that inappropriate management, such as cascading tanks, partial emptying of tanks and successive cultivations without time intervals, created conditions for the establishment of the population of E. gomesi in the evaluated fish farms.

Nile tilapia feed on plankton in natural environments. This food source can be increased in ponds through fertilization and can reduce feed expenses or improve fish performance when used as supplementary food. Organic fertilization is an alternative to commercial fertilization; however, its use increases concerns regarding water quality and sanitary aspects. This study aimed to evaluate the effects of the use of poultry litter as organic fertilizer on the physical and chemical parameters of water, gill ectoparasite metazoan abundance, and growth of Nile tilapia (Oreochromis niloticus) during the culture cycle lasting 240 days. Four earthen ponds, two fertilized with poultry litter and two non-fertilized ponds, as fertilized and non-fertilized treatments, respectively, were used. Stocking density was 3 fish per m2 with an average initial weight of 0.64 ± 0.15 g. The mean water quality values and the growth performance parameters of Nile tilapia did not show significant differences between the two treatments. The gill parasites found in the fish belonged to the class Monogenea, comprising two genera, Cichlidogyrus and Scutogyrus, with significant differences between treatments. The non-fertilized treatment showed a high abundance of parasites throughout the culture cycle months, with peak abundance in the months with low concentrations of dissolved oxygen in the water.