OPTITUN investigates, for the first time in a comprehensive way, how ocular endothermy develops and works in juvenile bluefin tuna (Thunnus thynnus), a key physiological adaptation that allows the eyes to be kept at a temperature higher than that of the water and optimize vision.

Although this mechanism is described in adult tuna, it is unknown how it is acquired and regulated in juvenile phases, precisely the most critical in aquaculture, where high mortality rates associated with disorientation, collisions, loss of appetite and visual problems are recorded.

The project combines histological, transcriptomic, epigenetic analyses, implantable thermal sensors and behavioural studies, to understand how ambient temperature – including marine heatwaves associated with climate change – influences the vision, well-being and survival of farmed juveniles.

The results will allow the identification of physiological and molecular biomarkers and the definition of optimal thermal ranges, generating practical recommendations to improve the management, animal welfare and sustainability of bluefin tuna farming.

The following entities act as collaborating entities: Planet Tuna, Star-Oddi (supplier of implantable thermal sensors), FARM ASSOCIATION of Aquaculture Companies of the Region of Murcia, Tuna Graso S. A. U. and Almadraba de La Azohía.