Hünicken Leandro A, Paolucci Esteban M, Lavinia Pablo D, Sylvester Francisco
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1425FQB, Argentina.
Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia', Av. Ángel Gallardo 470, Buenos Aires C1405DJR, Argentina.
Animals (Basel). 2024 Jun 21;14(13):1843. doi: 10.3390/ani14131843.
The broad global distribution of freshwater clams belonging to the genus is driven by multiple hermaphroditic lineages. These lineages, characterized by shared morphological traits and phenotypic plasticity, pose challenges to morphological identification. Genetic markers, such as the mitochondrial COI gene, play a crucial role in delineating these lineages and their ranges. Morphotypes represent observed phenotypic variations, while lineages are defined based on genetic markers. Here, we comprehensively review 's distribution in Argentina, discriminate extant lineages based on both morphological and genetic (COI) data, and describe variations in internal and external morphologies using 15 Argentine populations. Genetic analyses identified two mitochondrial lineages: the AR morphotype (FW5 haplotype) and CS morphotype (FW17 haplotype). Strikingly, despite having similar vectors, origins, and invasive stages, lineages exhibit virtually segregated distributions. However, mitochondrial haplotypes are found in sympatry mainly in northeastern Argentina where individuals with intermediate morphotypes exist, suggesting the presence of hybrids due to maternal genome retention. These findings contribute to the clarification of the identity and distribution of lineages in Argentina, where the genus has been found for over half a century. Similar studies are needed in other areas to better understand the invasion patterns of this successful and adaptable group.
属于该属的淡水蛤在全球广泛分布是由多个雌雄同体谱系驱动的。这些谱系具有共同的形态特征和表型可塑性，给形态学鉴定带来了挑战。遗传标记，如线粒体COI基因，在划分这些谱系及其范围方面起着关键作用。形态型代表观察到的表型变异，而谱系则基于遗传标记来定义。在这里，我们全面回顾了该属在阿根廷的分布情况，根据形态学和遗传学（COI）数据区分现存谱系，并利用阿根廷的15个种群描述其内部和外部形态的变异。遗传分析确定了两个线粒体谱系：AR形态型（FW5单倍型）和CS形态型（FW17单倍型）。令人惊讶的是，尽管这两个谱系具有相似的传播媒介、起源和入侵阶段，但它们的分布几乎是隔离的。然而，线粒体单倍型主要在阿根廷东北部同域分布，那里存在具有中间形态型的个体，这表明由于母本基因组保留而存在杂交种。这些发现有助于澄清该属在阿根廷的谱系身份和分布情况，该属在阿根廷已被发现半个多世纪。其他地区也需要进行类似的研究，以更好地了解这个成功且适应性强的群体的入侵模式。
