Morphological changes and energetic requirement during ontogenetic development of Chelon auratus (Risso, 1810)

Abstract

Morphology is a scientific discipline analyzing the shape of organisms (Adams et al., 2004), which has been used in ecology, evolution, palaeontology, and even fisheries and aquaculture. In fishes, variation in body shape is a key factor that can influence multiple traits such as, swimming, foraging, mating, migrations, and predator avoidance (Farré et al., 2016). The present study describes the morphological changes and the growth trajectories during the transformation from 24 to 54 days after hatching (dah) in the golden grey mullet, Chelon auratus (Risso, 1810) using geometric morphometric analysis (GMA). The results showed a decrease of morphological disparity with the somatic growth, which indicated a higher phenotypic variability in the first phase of ontogenetic development. Given that this variability could affect to metabolism, some individuals with different morphologies and with different hatching were selected for estimating their degree of metabolic activity by means of the Electron Transport System (ETS) analysis. Differences were clearly noted depending on age group, younger individuals present higher respiration rate. Moreover, respiration rate was related with body shape individuals in way that organisms with more developed body have high metabolism rate. Therefore, these findings emphasized the relevance of the intra-specific variability for any study on larval development.