Are developmental shifts the main driver of phenotypic evolution in Diplodus spp. (Perciformes: Sparidae)?

BMC Evolutionary Biology

Paolo Colangelo¹  Jacopo Pagani Guazzugli Bonaiuti²  Paolo Piras³  Daniele Ventura⁴  Giandomenico Ardizzone⁴ 

[1] 0000 0001 1940 4177, grid.5326.2, Research Institute on Terrestrial Ecosystems, National Research Council, Via Salaria km 29.300, 00015, Monterotondo, Rome, Italy;grid.7841.a, Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University, Via Borelli 50, 00161, Rome, Italy;grid.7841.a, Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University, Via Borelli 50, 00161, Rome, Italy;grid.7841.a, Department of Cardiovascular Respiratory Nephrologic and Geriatric Sciences, Sapienza University, Rome, Italy;grid.7841.a, Department of Environmental Biology, Sapienza University, Rome, Italy;

关键词: Evo-devo;    Morphological divergence;    Ontogenesis;    Evolutionary trajectory;    Mediterranean Sea;    Diplodus;   

DOI  :  10.1186/s12862-019-1424-1

来源: publisher

【 摘 要 】

BackgroundSparid fishes of the genus Diplodus show a complex life history. Juveniles have adaptations well suited to life in the water column. When fishes recruit into the adult population, individuals develop a radically differentiated shape that reflects their adaptation to the new benthic environment typical of the adult.A comparative analysis of ontogenetic trajectories was performed to assess the presence of divergence in the developmental pattern. By using a geometric morphometric approach, we investigated the pattern of shape variation across ontogenetic stages that span from early settlement to the adult stage in four species of the genus Diplodus. Landmarks were collected on the whole body of fishes to quantify the phenotypic variation along two well defined life stages, i.e. juvenile and adult.A comparative analysis of ontogenetic trajectories was performed to assess the presence of divergence in the developmental pattern. Subsequently, we investigated the patterns of integration and modularity as proxy for the alteration of the developmental processes. This have allowed to give an insight in morphological developmental patterns across ecologically and ontogenetically differentiated life stages and to investigate the process leading to the adult shape.ResultOur results suggest that the origin of morphological novelties in Diplodus spp. arise from shifts of the ontogenetic trajectories during development. During the settlement phase, the juveniles’ morphological shapes converge towards similar regions of the morphospace. When the four species approach the transition between settlement and recruitment, we observe the lowest level of inter- and intra-specific disparity. After this transition we detect an abrupt shift of ontogenetic trajectories, i.e. the path taken by species during development, that led to highly divergent adult phenotypes.DiscussionWe suggest that the evolution of new ecomorphologies, better suited to exploit different niches (pelagic vs. benthonic) and reduce inter-specific competition in Diplodus spp., are related to the shift in the ontogenetic trajectory that in turn is associated to changes in modularity and integration pattern.

【 授权许可】

CC BY