Russo Tommaso, Pulcini Domitilla, Bruner Emiliano, Cataudella Stefano
Laboratory of Experimental Ecology and Aquaculture, Department of Biology, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy.
J Morphol. 2009 Jan;270(1):83-96. doi: 10.1002/jmor.10674.
Demersal fishes have complex life cycles that involve an ontogenetic change in morphology, physiology, and behavior, as their pelagic larval stages colonize benthic habitats. The developmental transition between larvae and juveniles leads to very complex processes of morphogenesis and differentiation. These processes primarily determine changes in external morphology, which is shaped by selective pressures to optimize performance for basic activities such as swimming, escape from predators, and feeding. Fishes have provided fertile grounds for ecomorphological investigations throughout ontogeny, as the role of changing morphology in inducing ontogenetic niche shifts is not always clear. In this framework, some studies have demonstrated that certain species undergo gradual changes, whereas other species experience threshold effects in their ecomorphological relationships during ontogeny. In this study, the intraspecific allometry of the dusky grouper was examined. Geometric morphometric tools were used to quantify shape changes through the development, and a modular approach was also applied to analyze the pattern of covariation between three distinct blocks (head, trunk, and tail). For this purpose, a two-block Partial Least Square was computed. This method reveals that the pattern of changes in the overall body shape is the result of the modularized changes of these blocks.
底栖鱼类具有复杂的生命周期，包括形态、生理和行为上的个体发育变化，因为它们的浮游幼体阶段会定殖于底栖生境。幼体与幼鱼之间的发育转变会导致非常复杂的形态发生和分化过程。这些过程主要决定外部形态的变化，而外部形态是由选择性压力塑造的，这些压力旨在优化诸如游泳、逃避捕食者和觅食等基本活动的表现。在整个个体发育过程中，鱼类为生态形态学研究提供了丰富的素材，因为形态变化在引发个体发育生态位转变中的作用并不总是清晰的。在此框架下，一些研究表明某些物种会经历逐渐变化，而其他物种在个体发育过程中的生态形态关系中会经历阈值效应。在本研究中，对暗纹石斑鱼的种内异速生长进行了研究。使用几何形态测量工具来量化发育过程中的形状变化，并且还应用了模块化方法来分析三个不同模块（头部、躯干和尾部）之间的协变模式。为此，计算了一个双模块偏最小二乘法。该方法表明，整体身体形状的变化模式是这些模块模块化变化的结果。
