The present study evaluated the genetic variability of the broodstocks of tambaqui hatcheries in the Brazilian state of Pará. Samples were obtained from the caudal fin of 110 broodstocks from one hatchery in each of four municipalities (Santarém, Peixe-Boi, Breu-Branco, and Ulianópolis), representing all the individuals of each hatchery stock. The samples were genotyped using the multiplex system microsatellite markers. Data were used to calculate observed and expected heterozygosity, number of alleles per locus, and allelic richness. The effective population size and inbreeding coefficient were also calculated. The genetic differentiation between populations was evaluated by using F ST , and population structuring by the most likely number of genetically homogenous populations and Unweighted Pair Group Method (UPGMA); the arithmetic means were based on Nei's. The indices indicated a loss of genetic variability in the broodstocks from Ulianópolis, Peixe-Boi, and Breu-Branco in comparison with wild tambaqui populations, although this was not apparent in the Santarém stock. A moderate level of genetic differentiation was found among the tambaqui broodstocks based on the F ST estimates, which were reinforced by the structuring found in the Bayesian analysis and UPGMA. This reflects the domestication process, given that no such structuring is found in natural tambaqui populations. This moderate genetic differentiation associated with the loss of genetic variability found in the four tambaqui broodstocks from the state of Pará provides important insights for the development of future programs of genetic improvement, as well as the conservation of the genetic diversity of these stocks.

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.

ABSTRACT. Genetic variability is one of the important criteria for species conservation decisions. This study aimed to analyze the genetic diversity and the population differentiation of two natural populations of Arapaima gigas, a species with a long history of being commercially exploited. We collected 87 samples of A. gigas from Grande Curuai Lake and Paru Lake, located in the Lower Amazon region of Amazônia, Brazil, and genotyped these samples using a multiplex panel of microsatellite markers. Our results showed that the populations of A. gigas analyzed had high levels of genetic variability, which were similar to those described in previous studies. These two populations had a significant population differentiation supported by the estimates of F ST and R ST (0.06), by Bayesian analysis (K = 2), and by population assignment tests, which revealed a moderate genetic distance.

RESUMOEste artigo avaliou o comportamento do mercado mundial, nacional e da região Norte do Brasil, quanto à evolução da produção, consumo e balança comercial de pescados. Foram utilizados dados oficiais da Organização das Nações Unidade para Alimentação e Agricultura (FAO), Instituto Brasileiro de Geografia e Estatística (IBGE), Ministério da Pesca e Aquicultura (MPA) e Ministério do Desenvolvimento, Indústria e Comércio Exterior (MDIC). Os dados foram submetidos à análise descritiva para elaboração tabelas, gráficos e mapas. Os resultados indicam que a produção mundial e nacional de pescado tem crescido nas últimas décadas em função do desenvolvimento da aquicultura. A produção nacional apresenta pouca inserção no mercado internacional, pois é pequena quando comparada a outros países. As principais regiões produtoras de pescado são a Nordeste, Norte e o Sul, onde Santa Catarina é o estado de maior destaque, com o estado do Pará ocupando o segundo lugar. O Brasil e o estado do Pará apresentam excelente potencial para a expansão da aquicultura e o desenvolvimento dessa atividade é fundamental para ampliar a oferta de pescado, atender o crescimento do mercado consumidor e contribuir com a sustentabilidade da pesca extrativa, a partir da redução da pressão sobre os estoques pesqueiros de águas marinhas e continentais. PALAVRAS-CHAVE: Amazônia Brasileira, Análise de Mercado, Economia Pesqueira. BEHAVIOR OF FISH PRODUCTION AND MARKET IN BRAZIL AND THESTATE OF PARÁ ABSTRACT The article evaluates the behavior of the world market, national and the northern region of Brazil, regarding the evolution of production, consumption and trade balance of fish.

The characteristics of milk are controlled by several genes, with emphasis on the four genes from casein, CSN1S1; CSN1S2; CSN2 and CSN3, which are responsible encoding of fractions the milk protein. The study of genetic variants in these genes, seek to investigate alleles, insertions or deletions, that can directly refl ect on productive characteristics, indicating differences in milk quality, composition and yield. The CSN1S1 and CSN3 genes were analyzed in lactating Murrah buffaloes using nucleotide sequencing. An SNP was found in the amplifi ed fragment of the CSN1S1 gene, located in nucleotide number 2,123 of the promoter region in position nt-258 (A/G). As for the CSN3 gene, two SNPs of exon number 4 were identifi ed in codons 33 (ACC/ATC) and 34 (ACC/ ACT) of the analyzed fragment. This study contributes to important associations between genetic variants and the desired characteristics of milk and its derivatives in future studies, because the variants found may be associated with the quality of milk, enabling genetic selection to be assisted by molecular markers, indicating a major advance that makes it possible to select animals early.

No abstract

No abstract

No abstract