International Journal of Science, Engineering and TechnologyAuthors: Sanchali Sarkar, Dr. Anand Sur
Abstract: Aquatic and semi aquatic habitats across the globe are increasingly characterised by low and fluctuating oxygen availability due to natural processes and accelerating anthropogenic pressures. Many vertebrate and invertebrate taxa have evolved dual respiratory systems that combine aquatic and aerial modes of gas exchange as a strategy to survive and function in hypoxic or intermittently anoxic environments. Despite extensive species specific studies, the broader adaptive significance of dual respiration remains fragmented across physiological, evolutionary, and ecological literatures. This conceptual paper synthesises existing zoological research to examine how dual respiratory systems function as integrated adaptive strategies rather than isolated traits. Using a structured critical review approach, the study draws on comparative physiology, evolutionary biology, and ecological theory to analyse patterns in the emergence, regulation, and performance of dual respiration in oxygen poor habitats. The review highlights convergent evolutionary pathways, trade offs between respiratory efficiency and ecological opportunity, and the role of environmental variability as a selective force. Rather than presenting new empirical data, the paper outlines expected analytical outcomes from comparative and mixed method approaches, including trait matrices and adaptive pathway models. The study contributes a unified conceptual framework that links respiratory plasticity with habitat use, behaviour, and fitness. This synthesis has implications for understanding species resilience under climate driven deoxygenation and for guiding future empirical research on adaptive respiratory strategies.
DOI: https://doi.org/10.5281/zenodo.18835110
