The Eurasian perch (Perca fluviatilis) is an economically and environmentally important fish. Its distribution is changing because of many anthropogenic factors, including aquaculture and restocking. Careless dislocations enhance risk disrupt the established geographical genetic structure of this species. Set as a benchmark for future studies, this paper investigates the current perch status in the Baltic Sea Region. It presents the genetic diversity and phylogeographic relationships among 19 perch populations in Lithuania, Latvia and Belarus, on the basis of 489 perch sequences of the mtDNA D-loop region. Analysis of molecular data revealed that in the eastern part of the Baltic Sea Region, the genetic diversity of mtDNA D-loop of the perch was greater and different in comparison to that from other European locations. Based on SAMOVA results, perch samples were divided into four genetically distinct groups (I–IV). These groups indicate non-casual geographical distributions of genetically differentiated perch populations in Lithuania, Latvia and Belarus. The colonisation of the eastern part of the Baltic during the last deglaciation period resulted in perch populations that are genetically more complex than anticipated. The just-assessed current perch genetic diversity may be useful for monitoring its changes induced by growing anthropogenic activities in the Baltic Sea Region.

中文翻译：

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波罗的海地区东部欧亚鲈鱼（Perca fluviatilis）种群之间复杂的系统地理学关系

欧亚鲈鱼 (Perca fluviatilis) 是一种在经济和环境上都很重要的鱼类。由于许多人为因素，包括水产养殖和重新放养，其分布正在发生变化。粗心的错位增加了破坏该物种已建立的地理遗传结构的风险。作为未来研究的基准，本文调查了波罗的海地区目前的鲈鱼状况。它基于 mtDNA D-loop 区域的 489 个鲈鱼序列，介绍了立陶宛、拉脱维亚和白俄罗斯 19 个鲈鱼种群之间的遗传多样性和系统地理学关系。分子数据分析表明，在波罗的海东部地区，鲈鱼 mtDNA D-loop 的遗传多样性与欧洲其他地区相比更大且不同。基于 SAMOVA 结果，鲈鱼样品分为四个遗传不同的组（I-IV）。这些群体表明立陶宛、拉脱维亚和白俄罗斯的遗传分化鲈鱼种群的非偶然地理分布。在最后一次冰消期，波罗的海东部的殖民化导致鲈鱼种群在遗传上比预期的更复杂。刚刚评估的当前鲈鱼遗传多样性可能有助于监测波罗的海地区不断增长的人为活动引起的变化。在最后一次冰消期，波罗的海东部的殖民化导致鲈鱼种群在遗传上比预期的更复杂。刚刚评估的当前鲈鱼遗传多样性可能有助于监测波罗的海地区不断增长的人为活动引起的变化。在最后一次冰消期，波罗的海东部的殖民化导致鲈鱼种群在遗传上比预期的更复杂。刚刚评估的当前鲈鱼遗传多样性可能有助于监测波罗的海地区不断增长的人为活动引起的变化。