Larval Development in Tropical Gar (Atractosteus tropicus) Is Dependent on the Embryonic Thermal Regime: Ecological Implications under a Climate Change Context
This article belongs to the Special Issue Current Advances and Challenges in Fisheries and Aquaculture Science: Feature Papers for the New Journey of Fishes[EN] In ectotherm species, environmental temperature plays a key role in development, growth, and survival. Thus, determining how temperature affects fish populations is of utmost importance to accurately predict the risk of climate change over fisheries and aquaculture, critical to warrant nutrition and food security in the coming years. Here, the potential effects of abnormal thermal regimes (24, 28 and 32 °C; TR24, TR28, and TR32, respectively) exclusively applied during embryogenesis in tropical gar (Atractosteus tropicus) has been explored to decipher the potential consequences on hatching and growth from fertilization to 16 days post-fertilization (dpf), while effects on skeletal development and body morphology were explored at fertilization and 16 dpf. Egg incubation at higher temperatures induced an early hatching and mouth opening. A higher hatching rate was obtained in eggs incubated at 28 °C when compared to those at 24 °C. No differences were found in fish survival at 16 dpf, with values ranging from 84.89 to 88.86%, but increased wet body weight and standard length were found in larvae from TR24 and TR32 groups. Thermal regime during embryogenesis also altered the rate at which the skeletal development occurs. Larvae from the TR32 group showed an advanced skeletal development, with a higher development of cartilaginous structures at hatching but reduced at 16 dpf when compared with the TR24 and TR28 groups. Furthermore, this advanced skeletal development seemed to determine the fish body morphology. Based on biometric measures, a principal component analysis showed how along development, larvae from each thermal regime were clustered together, but with each population remaining clearly separated from each other. The current study shows how changes in temperature may induce craniofacial and morphological alterations in fish during early stages and contribute to understanding the possible effects of global warming in early development of fish and its ecological implicationsSIThis work was partially funded by “Study of the digestive physiology in larvae and juveniles of tropical gar (Atractosteus tropicus) based on histological, biochemical and molecular techniques” project (Ref. CB-2016-01-282765) from the National Council for Science and Technology (CONACyT) of Mexico. I.F. acknowledges the funding from the MICIU and the European Social Fund, “The European Social Fund invests in your future” through the Ramón y Cajal (Ref. RYC2018-025337-I) contract from the Plan Estatal de Investigación Científica y Técnica e Innovación 2017–2020Authors also thanks the support from the RED LARVAplus “Estrategias de desarrollo y mejora de la producción de larvas de peces en Iberoamérica” (117RT0521) funded by the Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo (CYTED
