Luz L A, Reis L L, Sampaio I, Barros M C, Fraga E
Centro de Ciências Agrárias, Universidade Estadual do Maranhão, São Luís, MA, Brazil.
Instituto de Estudos Costeiros, Universidade Federal do Pará, Bragança, PA, Brazil.
Braz J Biol. 2015 Nov;75(4):838-45. doi: 10.1590/1519-6984.00214. Epub 2015 Nov 10.
The red piranha, Pygocentrus nattereri, is an important resource for artisanal and commercial fisheries. The present study determines the genetic differentiation among P. nattereri populations from the northeastern Brazilian state of Maranhão. The DNA was isolated using a standard phenol-chloroform protocol and the Control Region was amplified by PCR. The PCR products were sequenced using the didesoxyterminal method. A sequence of 1039 bps was obtained from the Control Region of 60 specimens, which presented 33 polymorphic sites, 41 haplotypes, һ =0.978 and π =0.009. The neutrality tests (D and Fs) were significant (P < 0.05) for most of the populations analyzed. The AMOVA indicated that most of the molecular variation (72%) arises between groups. The fixation index was highly significant (FST = 0.707, P < 0.00001). The phylogenetic analyses indicated that the specimens represented a monophyletic group. Genetic distances between populations varied from 0.8% to 1.9%, and were <0.5% within populations. The degree of genetic differentiation found among the stocks of P. nattereri indicates the need for the development of independent management plans for the different river basins in order to preserve the genetic variability of their populations.
红腹食人鱼（Pygocentrus nattereri）是个体渔业和商业渔业的重要资源。本研究确定了来自巴西东北部马拉尼昂州的红腹食人鱼种群之间的遗传分化。使用标准的酚-氯仿方法分离DNA，并通过PCR扩增控制区。PCR产物采用双脱氧末端法测序。从60个样本的控制区获得了一段1039个碱基对的序列，该序列有33个多态性位点、41个单倍型，单倍型多样性（h）=0.978，核苷酸多样性（π）=0.009。对大多数分析的种群而言，中性检验（D和Fs）具有显著性（P<0.05）。分子方差分析（AMOVA）表明，大部分分子变异（72%）出现在种群组之间。固定指数非常显著（FST = 0.707，P < 0.00001）。系统发育分析表明，这些样本代表一个单系类群。种群之间的遗传距离在0.8%至1.9%之间，而种群内部的遗传距离<0.5%。红腹食人鱼种群之间发现的遗传分化程度表明，需要为不同流域制定独立的管理计划，以保护其种群的遗传变异性。
