Exploring the aquaculture potential of marine sponges (Phylum Porifera) in Kerala, India: A focus on growth dynamics and optimization of farming protocols

Marine sponge (Demosponges) culture gains importance based on their pharmacological (bioactive compounds), cosmeceutical and nutraceutical values (collagen) and biomaterials (biofilms). Moreover, their efficient filter-feeding nature, totipotency, plasticity, ecological resilience and excellent aquiferous system that supports bioremediation makes them a promising candidate for sustainable aquaculture. Several attempts in integrated aquaculture with an aim to increase sponge biomass and their use of microorganisms and contaminants in bioremediation sector shows impressive results. However, a critical limitation to its cultivation at large scale lies in the scarcity of quantitative data on its growth dynamics. There is no quantitative and qualitative data on the successful culture of marine sponges in India. Additionally, the current literature offers only fragmented and often non-comparable estimates of growth rates, typically derived from short-term observations. The highlighted knowledge gap hinders the optimization of farming protocols and the evaluation of productivity under different rearing conditions. As a preliminary attempt in India, we aim to provide new insights in the in-situ rearing of two different and biomedically important sponge species in the natural and confined environment and understand their growth dynamics. A photogrammetric approach was used to monitor the growth of sponge explants. Our research highlights the suitability of a three-dimensional approach for their growth monitoring with an average increase in volume corresponding to collagen and bioactive compound production. This contribution not only highlight the methodological challenges in monitoring sponges but also proposes future directions for experimental design and long term monitoring to unlock its full aquaculture potential in Asia.