ABSTRACT
Tambaqui (Colossoma macropomum) is among the most important fish species of the Amazon and one of the most cultivated in Brazil. In the present work we have evaluated the genetic variability of wild and captivity populations of C. macropomum. Enzymatic markers were used to estimate the genetic variability of 41 specimens from a wild group; and 30, 33 and 45 from three captivity groups, which came from Pentecostes (Ceará State), Jaboticabal (São Paulo State) and Itacoatiara (Amazonas State), respectively. Nine isoenzymic systems were used to evaluate the genetic variability of these populations. Using zimogram data we obtained the polymorphism level, allele number, allelic frequency, observed and expected heterozigosity, Wright F statistics (FIS, FST), genetic distance, level of similarity and group analysis. The isoenzymic data showed that, from the nine systems, six presented polymorphic loci (Fbp-2, G6pdh-2, G6pdh-3, Pgi-1, Pgi-2 and Pgm-1). The populations from Pentecostes and Jaboticabal presented loss of genetic variability and low heterozigosity, compared to the wild population and to the artificial population acquired at Itacoatiara fish farm. Based on these results and on fish farmer information we could consider the population from Itacoatiara as recently derived from a wild population. Concluding, we suggest that the artificial populations of tambaqui, which contain a
ABSTRACT
The objective of this work was to evaluate differents diets in development of L. vannamei post-larvae in intensive nurseries. In this experiment were used 264,000 PL10 with initial weight and length of 11.0 mg and 9.78 mm, respectively, distributed in 12 nurseries of 1,000 L, cultured during 10 days. Four treatments were tested (control CR40-ART, CR42:48¬-ART, CR42:48:52 and ART) which were composed of 4 artificial and 1 natural diets, with 3 repetitions, distributed in an entirely casualized experimental delineation. Post-larvae were fed in the proportion of 15 % of total biomass. The best survival rates were verified in the treatments CR42:48:52, CR42:48-ART, ART and CR40-ART, with 91.3; 90.5; 81.8 e 70.9% (P>0.05), respectively. The best development occurred in the shrimp of CR42:48:52 treatments, confirmed by Tukey Test (P
Objetivou-se avaliar diferentes dietas no desenvolvimento de pós-larvas do L. vannamei em berçários intensivos. Utilizaram-se 264.000 PL10 com peso e comprimento inicial de 11,0 mg e 9,78 mm, respectivamente, distribuídas em 12 berçários de 1.000 L, cultivadas durante dez dias. Foram testados quatro tratamentos (controle RC40-ART, RC42:48-ART, RC42:48:52 e ART), compostos por quatro dietas artificiais e uma natural, com três repetições, distribuídos em delineamento inteiramente casualizado. As pós-larvas foram alimentadas na proporção de 15% da biomassa total. As melhores taxas de sobrevivência foram verificadas nos tratamentos RC42:48:52, RC42:48-ART, ART e RC40-ART, com 91,3; 90,5; 81,8 e 70,9% (p > 0,05), respectivamente. O melhor desenvolvimento ocorreu nos camarões do tratamento RC42:48:52, confirmado pelo teste de Tukey (p 0,05), para o comprimento e peso final, ganho em peso e comprimento, conversão alimentar e incrementos, em comparação aos indivíduos do tratamento ART. No que se refere ao ganho de biomassa e biomassa final, o tratamento RC42:48:52 diferiu dos tratamentos RC40-ART e ART (p 0,05). Concluiu-se que a utilização de diferentes produtos com alto valor nutricional proporcionou elevados índices zootécnicos às pós-larvas, produzindo-se, dessa forma, camarões de excelente qualidade para o povoamento de viveiros de terminação.