Moya Fernando, Hernández Jordan, Suazo Manuel J, Saucède Thomas, Brickle Paul, Poulin Elie, Benítez Hugo A
Millennium Institute Biodiversity of Antarctic and Subantarctic Ecosystems (BASE), Santiago 7800003, Chile.
Laboratorio de Ecología Molecular, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile.
Animals (Basel). 2024 Aug 16;14(16):2376. doi: 10.3390/ani14162376.
is a genus of irregular brooding sea urchins to the Southern Ocean. Among the 11 described species, three shared morphological traits and present an infaunal lifestyle in the infralittoral from the Subantarctic province; in Patagonia, in Kerguelen, and in Tierra del Fuego and South Shetlands. The systematic of , based on morphological characters and incomplete phylogenies, is complex and largely unresolved. This study evaluates the shape variation among these species using geometric morphometrics analysis (GM). For this, 72 individuals from four locations; South Shetlands, Kerguelen, Patagonia, and Falklands/Malvinas were photographed, and 37 landmarks were digitized. To evaluate the shape differences among species, a principal component analysis and a Procrustes ANOVA were performed. Our results showed a marked difference between the Falklands/Malvinas and the other localities, characterized by a narrower and more elongated shape and a significant influence of location in shape but not sex. Additionally, the effect of allometry was evaluated using a permutation test and a regression between shape and size, showing significant shape changes during growth in all groups. The possibility that the Falklands/Malvinas group shows phenotypic plasticity or represents a distinct evolutionary unit is discussed. Finally, GM proved to be a powerful tool to differentiate these species, highlighting its utility in systematic studies.
是一类分布于南大洋的不规则育幼海胆。在已描述的11个物种中，有3个具有共同的形态特征，在亚南极区的潮下带呈现底内生物的生活方式；分布于巴塔哥尼亚、凯尔盖朗群岛、火地岛和南设得兰群岛。基于形态特征和不完整系统发育的的分类学很复杂，很大程度上尚未解决。本研究使用几何形态计量学分析（GM）评估这些物种之间的形状变异。为此，对来自四个地点（南设得兰群岛、凯尔盖朗群岛、巴塔哥尼亚和福克兰群岛/马尔维纳斯群岛）的72个个体进行了拍照，并对37个地标点进行了数字化处理。为了评估物种之间的形状差异，进行了主成分分析和普氏方差分析。我们的结果显示，福克兰群岛/马尔维纳斯群岛与其他地区之间存在明显差异，其特征是形状更窄、更细长，位置对形状有显著影响，但性别对形状没有影响。此外，使用置换检验和形状与大小之间的回归评估了异速生长的影响，结果表明所有组在生长过程中都有显著的形状变化。讨论了福克兰群岛/马尔维纳斯群岛群体表现出表型可塑性或代表一个独特进化单元的可能性。最后，GM被证明是区分这些物种的有力工具，突出了其在分类学研究中的实用性。
