In an attempt to identify a simple, reproducible, inexpensive and non-toxic method for obtaining high quality and quantity genomic DNA from fi sh fi n and larvae samples, modifi ed salt extraction protocol and modifi ed phenol-chloroform extraction protocol were compared. The samples obtained from different fi sh species (Brycon orbignyanus, Piaractus mesopotamicus, Oreochromis niloticus, Leporinus elongatus and Prochilodus lineatus) using salt extraction showed good DNA quality and quantity (DNA/RNA relationship 1.8-2.2). These DNA samples were successfully used in the amplifi cation of RAPD (Random Amplifi ed Polymorphic DNA) and microsatellite molecular markers, demonstrating the same effectiveness of this protocol in comparison with modifi ed phenol-chloroform extraction protocol. This DNA extraction procedure constitutes an alternative and effi cient replacement for previous protocols for improving fi sh molecular studies.

Body shape is a commercial trait of great interest as it impacts profit and productivity of aquaculture enterprises. In the present study, we examined correlated changes in two measures of body shape (depth to length ratio, DL-R and ellipticity of mid sagittal plane, EL-H) from a selection program for high daily weight gain in a Nile tilapia population reared in freshwater cages in Brazil. Genetic parameters for body shape and its genetic association with growth traits (body weight and daily gain) were also estimated from 8,725 individuals with growth performance recorded over five generations from 2008 to 2013. Mixed model analysis showed that the selection program resulted in substantial improvement in growth performance (about 4 % genetic gain per generation or per year) and also brought about trivial changes in body shape. The heritabilities ranged from 0.470 to 0.564 for growth traits and 0.180 to 0.289 for body shape. The common family effects were low for all traits studied, accounting for only 3-11 % of total phenotypic variance. The genetic correlations between body shape and growth traits were weak, i.e., -0.385 between EL-H and growth traits and 0.28 between DL-R and body weight or daily gain. Strong and negative genetic association was found between the two body shape traits (rg = --0.955). Harvest body weight and daily gain are essentially the same traits, as indicated by the close to one genetic correlations between the two characters. Our results demonstrated that the selection process to increase growth rate had small, but slowly constant effect in body shape traits; and in the long term, the fish would have become rotund.

J.A. Povh, N.M. Lopera-Barrero, R.P. Ribeiro, E. Lupchinski Jr., P.C. Gomes, and T.S. Lopes. 2008. Genetic monitoring of fi sh repopulation programs using molecular markers. Cien. Inv. Agr. 35(1):5-15. Native fi sh populations are decreasing due to several impact factors of the environment.In order to address this problem, several actions, for example stocking, have been accomplished. However, if these actions are undertaken without any scientifi c support, their effi ciency is low, and they can cause loss of genetic diversity in the populations, and irreversible impacts in the next generations. For this reason, the use of molecular markers to assess diversity through genetic monitoring, can contribute to the conservation of the icthyofauna.

Efeito do núcleo homeopático homeopatila 100® na eficiência produtiva em alevinos revertidos de tilápia do nilo (Oreochromis niloticus)Effect of core homeopathic homeopatila 100® in productive efficiency of fingerlings reverted from nile tilapia (Oreochromis niloticus) ResumoFoi pesquisado o efeito do Núcleo Homeopático Homeopatila 100® na integridade histológica branquial, na sobrevivência, peso, comprimento final, conversão alimentar aparente e índice hepatossomático em alevinos de tilápia do Nilo (Oreochromis niloticus). Foi utilizado um tratamento controle (T1) com 20mL de solução hidroalcólica (álcool 30° GL) a cada kg de ração e três tratamentos com 20mL/kg (T2), 40mL/kg (T3) e 60mL/kg (T4) do Núcleo Homeopático Homeopatila 100®, em alevinos machos revertidos, com peso e comprimento médio inicial de 1,05 ± 0,32g e 4,15 ± 0,42cm respectivamente. Foi distribuído um total de 832 alevinos em 16 caixas d´agua com capacidade individual de 2000 litros, contendo 1000 litros cada uma, onde permaneceram durante 61 dias. No final do experimento, não foi observada diferença estatística entre os diferentes tratamentos nas alterações histológicas examinadas nas brânquias: elevação epitelial, hiperplasia, telangectasia e fusão lamelar. Os alevinos que receberam 40mL/kg de ração de Homeopatila 100® (T3) apresentaram maior sobrevivência e índice hepatossomático menor do que os alevinos do grupo controle (T1). Palavras-chave: Aqüicultura, histologia, homeopatia populacional, piscicultura AbstractIt was researched the effect of Core Homeopathic Homeopatila 100® on the integrity branchial histological, weight, final length, survival, feed conversion and apparent index hepatossomátic in fingerlings from Nile tilapia (Oreochromis niloticus). We used in the control treatment (T1) with 20mL/ kg water-alcohol solution (alcohol 30 GL) and three treatments with 20mL/kg (T2), 40mL/kg (T3) e 60mL/kg (T4) of core homeopathic Homeopatila 100® in fingerlings male reversed, with initial weight and initial length the 1,05 ± 0,32g and 4,15 ± 0,42cm respectively. It was distributed a total of 832 fingerlings in 16 polyethylene water tanks with individual capacity of 2000 liters, contends 1000 liters each one, where they ha remained during 61 days. At the end of experiment, was not observed statistic difference between the different treatments in histological changes examined in gills: epithelial lifting, hyperplasia, telangectasy and lamellar fusion. The fingerlings which received 40mL/kg of Homeopatila 100® (T3) showed a higher rate of survival and also lower rate than the other hepatossomátic the fingerlings in control group (T1).

Resumo -O objetivo deste trabalho foi avaliar a diversidade genética em quatro estoques de tambaquis (Colossoma macropomum) de diferentes regiões do Brasil, por meio de marcador RAPD. Foram utilizados 10 iniciadores para analisar 116 indivíduos, coletados de pisciculturas nos municípios de Urupá, RO, Teixeirópolis, RO, Neópolis, SE e Sorriso, MT. Foram encontradas diferenças nas frequências de 67 fragmentos, com um fragmento exclusivo em Sorriso e dois em Neópolis. Observaram-se altos valores de polimorfismo (72,92 a 83,33%), diversidade genética de Nei (0,27 a 0,30) e índice de Shannon (0,39 a 0,45). A análise da variância molecular, demonstrou que a maior parte da variação está dentro de cada estoque e não entre os estoques.A identidade e a distância genética entre os agrupamentos variou de 0,93 a 0,98 e 0,02 a 0,07, respectivamente, com menos distância entre os agrupamentos Urupá x Sorriso e entre Teixerópolis x Neópolis. A diferenciação genética variou de baixa a moderada (F st = 0,03 a 0,15) e o número de migrantes por geração foi alto (Nm = 5,96 a 24,3), entre os agrupamentos. Os estoques apresentam alta variabilidade e baixa diferenciação e distância genética entre si.Termos para indexação: Colossoma macropomum, diversidade genética, RAPD. Genetic variability of tambaqui (Teleostei: Characidae) from different regions of BrazilAbstract -The objective of this study was to evaluate the genetic diversity of four broodstocks of tambaqui (Colossoma macropomum) from different regions of Brazil using RAPD markers. Ten primers were used to analyze 116 individuals, collected from fish cultures of three municipalities in Brazil: Urupá, RO; Teixeirópolis, RO; Neópolis, SE; and Sorriso, MT. Differences in the frequencies of 67 fragments were found, with a unique fragment in Sorriso and two in Neópolis. High values of polymorphism (72.92 to 83.33%), Nei's genetic diversity (from 0.27 to 0.30) and Shannon index (from 0.39 to 0.45) were observed. Analysis of molecular variance showed that most of the variation is within each broodstock and not among them. The identity and genetic distance among the groups ranged from 0.93 to 0.98 and from 0.02 to 0.07, respectively, with less distance between clusters Urupá x Sorriso and Teixerópolis x Neópolis. Genetic differentiation ranged from low to moderate (F st = 0.03 to 0.15) and the number of migrants per generation was high (Nm = 5.96 to 24.3) among the groups. Stocks have high variability and low genetic differentiation and distance among them.

The quality and sensory acceptability of fish fillet (Oreochromis niloticus) with alginate-based coating containing ginger and oregano essential oils (EO) were evaluated. The antioxidant activity of essential oil, coating, and fish were also investigated. In relation to lipid oxidation, a decrease was observed in fish with the edible coatings compared to the control being the coating with oregano EO the most effective and also with the highest antioxidant activity. Loss in color and weight were significantly lower with coating. Fish with coating maintained firmness whereas fish without coating became softer. Fish with edible coating and oregano essential oils showed higher sensory acceptability regarding to odor evaluated by consumers. Thus, edible coatings with essential oils as natural antioxidant improved the product quality and sensory acceptability.

-The objective of this study was to estimate genetic parameters for survival and weight of Nile tilapia (Oreochromis niloticus), farmed in cages and ponds in Brazil, and to predict genetic gain under different scenarios. Survival was recorded as a binary response (dead or alive), during harvest time in the 2008 grow-out period. Genetic parameters were estimated using a Bayesian mixed linear-threshold animal model via Gibbs sampling. The breeding population consisted of 2,912 individual fish, which were analyzed together with the pedigree of 5,394 fish. The heritabilities estimates, with 95% posterior credible intervals, for tagging weight, harvest weight and survival were 0.17 (0.09-0.27), 0.21 (0.12-0.32) and 0.32 (0.22-0.44), respectively. Credible intervals show a 95% probability that the true genetic correlations were in a favourable direction. The selection for weight has a positive impact on survival. Estimated genetic gain was high when selecting for harvest weight (5.07%), and indirect gain for tagging weight (2.17%) and survival (2.03%) were also considerable.Index terms: Oreochromis niloticus, correlation, fish genetic improvement, Gibbs sampling, GIFT strain, heritability. Parâmetros genéticos bayesianos para peso corporal e sobrevivência de tilápias-do-nilo cultivadas no BrasilResumo -O objetivo deste trabalho foi estimar parâmetros genéticos para a sobrevivência e peso de tilápias-do-nilo (Oreochromis niloticus), cultivadas em tanques-rede e viveiro de terra no Brasil, e predizer o ganho genético sob diferentes cenários. Mediu-se a sobrevivência como uma característica binária (peixe vivo ou morto), no período de crescimento de 2008 até a despesca. Os paramêtros genéticos foram estimados pelo modelo animal limiar-linear em análise bayesiana, pela amostragem de Gibbs. A população avaliada foi de 2.912 peixes individuais, que foram analisados juntamente com o pedigree de 5.394 peixes. As herdabilidades, com intervalos de credibilidade de 95%, obtidas para peso à identificação, peso à despesca e sobrevivência foram 0,17 (0,09-0,27), 0,21 (0,12-0,32) e 0,32 (0,22-0,44), respectivamente. Intervalos de credibilidade mostram 95% de probabilidade de que as verdadeiras correlações genéticas estejam em uma direção favorável. A seleção para peso tem impacto positivo na sobrevivência. O ganho genético estimado foi alto para a seleção quanto ao peso à despesca (5,07%), e o ganho indireto para o peso à identificação (2,17%) e à sobrevivência (2,03%) também foram consideráveis.Termos para indexação: Oreochromis niloticus, correlação, melhoramento genético de peixes, amostragem de Gibbs, linhagem GIFT, herdabilidade.

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