The emergence of Skin Ulceration Diseases in Edible Sea Cucumbers in a Global Change Framework – SKUD

Holothurians or sea cucumbers (Holothuroidea) form one of the five classes of the phylum Echinodermata.Throughout the world, out of the 1,400 existing species, 66 are commonly exploited and of particularimportance for the Indo-Pacific communities. They are exported to China where people consider them asdelicate meals with important pharmacological properties. Aquaculture is the fastest growing food sector andto face the sea cucumber situation, aquaculture programs have been developed. During the last 15 years,the Belgian team involved in the present project developed in Madagascar a unique method that insures asufficient production of H. scabra, a species with economic interests, to make its aquaculture profitable.Today, the Belgian project is on track in this country with many demands coming from other countries fordeveloping this new type of aquaculture. One of the main risks to the development of aquaculture is theemergence of diseases, especially the SKin Ulceration Diseases or SKUDs where the first symptom is anulceration of the holothuroid’s skin.Since January 2017, the supervisor of the present project (Igor Eeckhaut) started a research project (WISD)granted by the FNRS (Belgium) whose overall objective is to provide the scientific support necessary for thedevelopment of holothuriculture. This project aims to secure the development of sea cucumber villagefarming with a part about the characterization of SKUDs in the aquacultures of Madagascar.The present project aims to study the emergence of diseases, especially SKUDs, in edible sea cucumbersoutside Madagascar, especially in Thailand and France, and that in a global change framework. The specificobjectives are (i) to make a survey of parasites and diseases of two edible sea cucumbers (Holothuriaforskali in France and Holothuria scabra in Thailand), (ii) to determine the cause(s) of SKUDs on thesespecies and (iii) to assess on these species the effects of increased temperature and decreased pH onSKUD prevalence and development, at values commensurate with predicted global changes.The project, that will last three years, links four teams: the “Biology of Marine Organisms and Biomimetics”laboratory of the University of Mons (Belgium), the Marine Biology Laboratory of the ULB (Belgium), theSeaweed and Seagrass Research Unit, Prince of Songkla University (Thailand) and the Marine BiologyStation of Concarneau (Muséum National d'Histoire Naturelle of Paris, France).The activities will include (i) a survey of H. scabra’s parasites and diseases in Thailand and of H. forskali inFrance; (ii) an histological study (indlucing TEM and SEM) with a metagenomic analyses of infected tissuesin Belgium after samplings in Thailand and France; (iii) field experiments on transfections and aquariumexperiments on the effects of global change on disease prevalence and extension; (iv) a workshop on seacucumber diseases organized in France