Kuciński Marcin, Jakubowska-Lehrmann Magdalena, Góra Agnieszka, Mirny Zuzanna, Nadolna-Ałtyn Katarzyna, Szlinder-Richert Joanna, Ocalewicz Konrad
Department of Marine Biology and Ecology, Institute of Oceanography, University of Gdansk, Piłsudskiego Ave. 46, 81-378 Gdynia, Poland.
Department of Fisheries Oceanography and Marine Ecology, National Marine Fisheries Research Institute, Kołłątaja 1 Street, 81-332 Gdynia, Poland.
Animals (Basel). 2023 Apr 24;13(9):1448. doi: 10.3390/ani13091448.
The European flounder (), which is closely related to the recently discovered Baltic flounder (), is currently the third most commercially fished species in the Baltic Sea. According to the available data from the Polish Fisheries Monitoring Center and fishermen's observations, the body condition indices of the species in the Baltic Sea have declined in recent years. The aim of the present study was to obtain information on the current patterns of genetic variability and the population structure of the European flounder and to verify whether the Baltic flounder is present in the southern Baltic Sea. Moreover, we aimed to verify whether the observed decline in the body condition indices of the species in the Baltic Sea might be associated with adaptive alterations in its gene pool due to increased fishing pressure. For this purpose, 190 fish were collected from four locations along the central coastline of Poland, i.e., Mechelinki, Władysławowo, the Vistula Lagoon in 2018, and the Słupsk Bank in 2020. The fish were morphologically analyzed and then genetically screened by the application of nineteen microsatellite DNA and two diagnostic SNP markers. The examined European flounder specimens displayed a high level of genetic diversity ( = 0.832-0.903, = 2.579-2.768). A lack of significant genetic differentiation ( = 0.004, > 0.05) was observed in all the examined fish, indicating that the European flounder in the sampled area constitutes a single genetic cluster. A significant deficiency in heterozygotes ( = 0.093, < 0.05) and overall deviations from Hardy-Weinberg expectations (H-WE) were only detected in fish sampled from the Słupsk Bank. The estimated effective population size () among the sampled fish groups varied from 712 (Słupsk Bank) to 10,115 (Władysławowo and Mechelinki). However, the recorded values of the Garza-Williamson indicator ( = 0.574-0.600) and the lack of significant ( > 0.05) differences in > under the model did not support the species' population size changes in the past. The applied SNP markers did not detect the presence of the Baltic flounder among the fish sampled from the studied area. The analysis of an association between biological traits and patterns of genetic diversity did not detect any signs of directional selection or density-dependent adaptive changes in the gene pool of the examined fish that might be caused by increased fishing pressure.
欧洲比目鱼（）与最近发现的波罗的海比目鱼（）密切相关，目前是波罗的海商业捕捞量第三大的物种。根据波兰渔业监测中心的现有数据和渔民的观察，近年来波罗的海该物种的身体状况指数有所下降。本研究的目的是获取有关欧洲比目鱼当前遗传变异模式和种群结构的信息，并验证波罗的海比目鱼是否存在于波罗的海南部。此外，我们旨在验证在波罗的海观察到的该物种身体状况指数下降是否可能与捕捞压力增加导致其基因库的适应性改变有关。为此，从波兰中部海岸线的四个地点收集了190条鱼，即2018年的梅切林斯基、弗瓦迪斯瓦沃、维斯瓦泻湖，以及2020年的斯武普斯克浅滩。对这些鱼进行形态分析，然后应用19个微卫星DNA和两个诊断性SNP标记进行基因筛选。所检测的欧洲比目鱼标本显示出高水平的遗传多样性（=0.832 - 0.903，=2.579 - 2.768）。在所有检测的鱼中均未观察到显著的遗传分化（=0.004，>0.05），这表明采样区域内的欧洲比目鱼构成一个单一的遗传簇。仅在从斯武普斯克浅滩采样的鱼中检测到杂合子的显著不足（=0.093，<0.05）以及总体偏离哈迪 - 温伯格预期（H - WE）的情况。采样鱼群中的有效种群大小（）估计值从712（斯武普斯克浅滩）到10,115（弗瓦迪斯瓦沃和梅切林斯基）不等。然而，记录的加尔扎 - 威廉姆森指标值（=0.574 - 0.600）以及在模型下>时缺乏显著差异（>0.05）并不支持该物种过去种群大小的变化。所应用的SNP标记未在研究区域采样的鱼中检测到波罗的海比目鱼的存在。对生物学特征与遗传多样性模式之间关联的分析未发现所检测鱼的基因库中可能由捕捞压力增加引起的定向选择或密度依赖性适应性变化的任何迹象。
