The main objective of this study was to estimate the genetic diversity levels and haplotype traceability in pacu Piaractus mesopotamicus from the breeding program located in Brazil by analyses of the mitochondrial DNA control region (mtDNA). Moreover, broodstocks from eight commercial fish farms were used for comparative evaluation, four from Brazil (Br1-Br4) and four from Argentina (Ar1-Ar4). The descriptive results revealed 47 polymorphic sites and 51 mutations, which evidenced 34 haplotypes. Ten haplotypes were shared among fish farms and 24 were exclusive. The nucleotide diversity (π) ranged from 0.00031 to 0.01462 and haplotype diversity (Hd) from 0.125 to 0.868. The analysis of molecular variance (AMOVA) indicated high structure present in the analyzed stocks (FST = 0.13356 and ФST = 0.52707). The genetic diversity was high in most of the commercial broodstocks, especially those from Brazil. We observed seven haplotypes in the genetic breeding population, of which four were exclusive and three shared among the commercial fish farms. The genetic diversity was moderate (π = 0.00265 and Hd = 0.424) and considered appropriated for this breeding population of pacu. Our results provide support for the genetic diversity maintenance and mtDNA traceability of pacu commercial broodstocks.

中文翻译：

---

线粒体DNA揭示的pacu（Piaractus mesopotamicus）繁殖种群的单倍型可追溯性和遗传变异性。

这项研究的主要目的是通过对线粒体DNA控制区（mtDNA）的分析，通过位于巴西的育种计划来估计美洲豹（Pacu Piaractus mesopotamicus）的遗传多样性水平和单倍型可追溯性。此外，将来自八个商业养鱼场的亲鱼用于比较评价，其中四个来自巴西（Br1-Br4），四个来自阿根廷（Ar1-Ar4）。描述性结果揭示了47个多态性位点和51个突变，证明了34个单倍型。养鱼场共有10个单倍型，而排他性有24个。核苷酸多样性（π）的范围为0.00031至0.01462，单倍型多样性（Hd）的范围为0.125至0.868。分子变异分析（AMOVA）表明，所分析的库存中存在高结构（FST = 0.13356和ФST= 0.52707）。大多数商业亲鱼的遗传多样性很高，尤其是来自巴西的亲鱼。我们在遗传育种种群中观察到7种单倍型，其中4种是独占型，而3种在商业养鱼场之间共享。遗传多样性是中等的（π= 0.00265和Hd = 0.424），被认为适合该种群的pacu繁殖。我们的结果为pacu商业亲鱼的遗传多样性维持和mtDNA可追溯性提供了支持。