Mediterranean commercial sponges: over 5000 years of natural history and cultural heritage (Review)

This paper deals with the history of the exploitation of a natural resource made up of various types of Mediterranean horny sponges. It also provides an update on trends in the trade of these sponges. The distribution and taxonomic status of Mediterranean species of commercial interest belonging to the genera Spongia and Hippospongia are reported upon and partly emended by (i) the selection of neotypes for Spongia mollissima, Hippospongia communis, and Spongia agaricina from the Indo-Pacific Ocean versus the Mediterranean Spongia lamella, and (ii) the discussion regarding the problematic status of Spongia zimocca. Attention is also focused upon species that have been of recent commercial interest as sources of metabolites with biomedical potential, such as Dysidea avara, which is considered endangered due to a pressing demand for the industrial extraction of chemicals it produces (e.g. Avarol). The wild harvesting of new target sponges is also discussed, together with a proposal for a rational, sustainable, long-term strategy for Mediterranean sponge management. Sponge culture in situ is suggested as a useful approach that may allow eco-compatible management and conservation of this natural resource.