Ramler David, Palandačić Anja, Delmastro Giovanni B, Wanzenböck Josef, Ahnelt Harald
First Zoological Department Museum of Natural History Vienna Vienna Austria; Department of Limnology and Bio-Oceanography University of Vienna Vienna Austria.
First Zoological Department Museum of Natural History Vienna Vienna Austria.
Ecol Evol. 2016 Dec 20;7(2):572-584. doi: 10.1002/ece3.2648. eCollection 2017 Jan.
Minnows of the genus are promising candidates to investigate adaptive divergence, as they inhabit both still and running waters of a variety of altitudes and climatic zones in Europe. We used landmark-based geometric morphometric methods to quantify the level of morphological variability in populations from streams and lakes of Northern Italy and the Danube basin. We analyzed body shape differences of populations in the dorsal, lateral, and ventral planes, using a large array of landmarks and semilandmarks. As the species identification of on morphological characters is ambiguous, we used two mitochondrial genes to determine the genetic background of the samples and to ensure we are comparing homogenous groups. We have found significant body shape differences between habitats: Minnow populations inhabiting streams had a deeper body and caudal peduncle and more laterally inserted pectoral fins than minnows inhabiting lakes. We have also found significant body shape differences between genetic groups: Italian minnows had deeper bodies, deeper and shorter caudal peduncles, and a shorter and wider gape than both groups from the Danube. Our results show that the morphology of is highly influenced by habitat and that body shape variation between habitats was within the same range as between genetic groups. These morphological differences are possibly linked to different modes of swimming and foraging in the respective habitats and are likely results of phenotypic plasticity. However, differences in shape and interlandmark distances between the groups suggest that some (though few) morphometric characters might be useful for separating species.
属的米诺鱼是研究适应性分化的有前途的候选对象，因为它们栖息在欧洲各种海拔和气候带的静水和流水中。我们使用基于地标点的几何形态测量方法来量化来自意大利北部溪流和湖泊以及多瑙河流域的米诺鱼种群的形态变异水平。我们使用大量地标点和半地标点分析了种群在背侧、侧面和腹侧平面上的体型差异。由于基于形态特征对米诺鱼进行物种鉴定并不明确，我们使用两个线粒体基因来确定样本的遗传背景，并确保我们比较的是同质群体。我们发现不同栖息地之间存在显著的体型差异：栖息在溪流中的米诺鱼种群比栖息在湖泊中的米诺鱼身体更深、尾柄更粗，胸鳍插入位置更靠侧面。我们还发现不同遗传群体之间存在显著的体型差异：意大利米诺鱼的身体更深，尾柄更深且更短，口裂更短更宽，比来自多瑙河的两个群体都如此。我们的结果表明，米诺鱼的形态受到栖息地的高度影响，并且栖息地之间的体型差异与遗传群体之间的差异处于同一范围内。这些形态差异可能与各自栖息地中不同的游泳和觅食方式有关，并且很可能是表型可塑性的结果。然而，不同群体之间在形状和地标点间距离上的差异表明，一些（尽管很少）形态测量特征可能有助于区分米诺鱼物种。
