Optimização do bem-estar do polvo em condições de cultivo

Aquaculture can be part of the solution to meet the UN 2030 global agenda, and there is an increasing interest in octopus culture due to its economic and nutritional values. The common octopus (Octopus vulgaris) is the most important marine living resource in terms of monetary value in Portugal (~32 million euros in 2020; see Annex 1), and, therefore, its aquaculture will have important implications at commercial/societal levels. Yet, urgent octopus welfare regulations are needed. Within this context, OCTOCULT aims to test, for the first time, a comprehensive and multidisciplinary set of potential octopus welfare indicators in culture settings. It will encompass different levels of biological organization and research fields, including biochemistry (Task 2), behavior (Task 3), physiology (Task 4) and immunology (Task 5). Four (5-month long) different experiments will be performed (Task 1), aiming to test octopus responses to different: i) stocking densities; ii) shelter provisioning and competition scenarios; iii) individual partition types; and iv) cognitive enrichment. All four experiments will extract growth-related data (absolute and specific feeding rates, absolute and specific growth rate, feed efficiency, feed conversion ratio, and digestive gland index) (Task 2). Alongside, proximate composition and fatty acid and amino acid profiling will also be analyzed (Task 2). At the behavioral level (Task 3), exploratory and play behaviors will be evaluated with machine learning techniques, which may also constitute key welfare indicators. Judgment bias tests will also be performed for the first time in octopus. At physiological level (Task 4), antioxidant enzyme activities, heat shock protein and ubiquitin levels, DNA damage, lipid peroxidation, and total antioxidant capacity will be quantified to evaluate oxidative stress. Additionally, neurotransmitter profiling and neuronal density, and brain electrical activity will be evaluated to investigate octopus inner states. Because immunology is a promising field in studying octopus health and welfare, on Task 5, hemocyte and key humoral factor (lysozymes, acid phosphatases, protease inhibitors, phenoloxidase and prophenoloxidase) contents will be evaluated. With this multidisciplinary approach, OCTOCULT will provide a deeper comprehensive understanding of Octopus vulgaris physiological and behavioral requirements, and stress responses to unsuitable housing and husbandry conditions. There is a strong debate about the pros and cons of octopus culture in many different forums, including inside academia [1*]. Therefore, there is a great need to develop and consolidate a solid scientific base for octopus welfare regulations in culture settings. Within this context, the importance of raising a high degree of public involvement and participation through dissemination activities is also a crucial goal of OCTOCULT. Alongside, OCTOCULT has the potential to play a significant role in advancing several SDGs simultaneously, contributing to broader sustainable development efforts.