Loy A, Bertelletti M, Costa C, Ferlin L, Cataudella S
Laboratorio di Ecologia Sperimentale & Acquacoltura, Dipartimento di Biologia, Università di Roma Tor Vergata, Rome, Italy.
J Morphol. 2001 Oct;250(1):24-33. doi: 10.1002/jmor.1056.
The larvae of three species of the genus Diplodus (Diplodus vulgaris, D. sargus, and D. puntazzo) colonize shallow waters along the Mediterranean coasts and, after a short period spent in the water column, they settle. For all three species this habitat transition is characterized by important shape changes mostly related to swimming capacity and feeding behavior. In this study, geometric morphometrics are used to characterize shape changes during the early juvenile life of specimens collected in a single locality in order to compare growth curves and allometric relationships. Size-related shape changes proved to be similar for all three species and are consistent with the ecological transition. A nonparametric smoothing technique (Loess) was used to fit the scatter of shape on size. The graphical representation (of most size-related shape variability) of this fitting technique shows how major shape changes are rapid for small sizes and slow down successively. The approach allows for the visualization of allometry and the fitting technique might help in defining the allometric growth pattern, thus contributing to the study of the autoecology of the species and in establishing terms for comparison with other ecologically or phylogenetically related species.
笛鲷属的三个物种（普通笛鲷、黄鳍笛鲷和斑鳍笛鲷）的幼体栖息在地中海沿岸的浅水区，在水柱中度过短时间后便定居下来。对于这三个物种而言，这种栖息地转变的特征是重要的形态变化，主要与游泳能力和摄食行为有关。在本研究中，几何形态测量学被用于描述在单个地点采集的标本幼鱼早期生活阶段的形态变化，以便比较生长曲线和异速生长关系。事实证明，这三个物种与大小相关的形态变化相似，且与生态转变一致。使用非参数平滑技术（局部加权回归散点平滑法）来拟合形态随大小的散点图。这种拟合技术的图形表示（大多数与大小相关的形态变异性）显示出，对于小尺寸个体，主要形态变化迅速，随后逐渐减缓。该方法能够实现异速生长的可视化，并且这种拟合技术可能有助于确定异速生长模式，从而有助于该物种的自身生态学研究，并为与其他生态或系统发育相关物种的比较建立标准。
