Data from: Strong population structure and shallow mitochondrial phylogeny in the banded guitarfish, Zapteryx exasperata (Jordan y Gilbert, 1880) from the northern Mexican Pacific

The northern Mexican Pacific (NMP), the Gulf of California (GC), and Baja California have been recognized as an ecological and evolutionarily dynamic region having experienced significant tectonic and climatic changes leading to the diversification of terrestrial and marine biotas. Zapteryx exasperata is a predominant ray caught in the artisanal fisheries of the NMP. Morphometric and reproductive differences between rays from the GC and the Pacific Coast of Baja California (PCBC) regions suggest the presence of distinct populations. We investigate whether this distinction correlates with differences in genetic diversity and differentiation using sequences of the mitochondrial ND2 gene and the non-coding control region (CR) in 63 specimens. Contrary to our expectations, ND2 bore significantly more diversity (h = 0.76) than CR (h = 0.39). Geographic patterns of diversity of CR were opposite to those of ND2, with GC being significantly less (ND2) and more (CR) diverse than PCBC. The diversity of concatenated haplotypes was high (h = 0.84). Low nucleotide diversity suggests the recent coancestry of haplotypes. Marked genetic structure (Φst = 0.23 p < 0.0001) revealed the existence of reproductive isolation and limited matrilineal gene flow between GC and PCBC, which correlates with their phenotypic distinction. These results suggest the influence of factors such as female reproductive philopatry, and ecological or historical vicariant barriers to gene flow. Our results point to the existence a distinct management unit of banded guitarfish in each region, and add to the increasing evidence attesting to the diversifying nature of this evolutionarily dynamic region.

墨西哥北太平洋（northern Mexican Pacific, NMP）、加利福尼亚湾（Gulf of California, GC）以及下加利福尼亚地区被公认为兼具生态与演化动态性的区域，该区域经历了显著的构造运动与气候变化，推动了陆地与海洋生物类群的多样化分化。斑纹犁头鳐（Zapteryx exasperata）是墨西哥北太平洋小型手工渔业中的优势捕获鳐类。加利福尼亚湾与下加利福尼亚太平洋沿岸（Pacific Coast of Baja California, PCBC）区域的该种鳐类在形态计量学与繁殖特征上存在显著差异，提示存在两个独立的种群。本研究通过对63个样本的线粒体ND2基因以及非编码控制区（non-coding control region, CR）序列进行分析，探究上述表型差异是否与遗传多样性及遗传分化差异存在关联。与预期相悖的是，ND2基因的单倍型多样性（h=0.76）显著高于CR区（h=0.39）。CR区的多样性地理分布模式与ND2基因恰好相反：加利福尼亚湾的ND2多样性显著低于下加利福尼亚太平洋沿岸，而CR区多样性则显著更高。联合拼接的单倍型多样性较高（h=0.84）。较低的核苷酸多样性提示各单倍型间具有较近的共同祖先。显著的遗传结构（Φst=0.23，p<0.0001）表明，加利福尼亚湾与下加利福尼亚太平洋沿岸之间存在生殖隔离以及有限的母系基因流，这与其表型分化特征相吻合。上述结果提示，雌性繁殖恋地性、生态或历史成因的基因流阻隔屏障等因素可能发挥了调控作用。本研究结果表明，每个区域均存在一个独特的斑纹犁头鳐管理单元，同时也为这一演化动态区域的生物多样化特性增添了新的实证支持。