show Abstracthide AbstractResearch on marine pollution and its impacts on biota has focused over the last 15years on an important anthropic pollutant, plastic, and specifically on the effects ofmicroplastics on marine organisms. Of varied types and size, they have different originsdepending on their final use and carry chemical pollutants that can contribute todiversification of damage in organisms exposed to these microparticles. Although wehave an extensive literature on the physical effects of microplastics on marine biota, thechemical effects of additives and pollutants adsorbed to its structure are still poorlyknown, especially in basal metazoan organisms such as sponges. Among additives withpresence in the marine ecosystem, DEHP (Di(2ethylhexyl phthalate)), a product used asplasticizer to increase the malleability of polymers such as PVC, has the greaterconcentration. Potent endocrine disruptor in vertebrates, recently DEHP was found insponges tissues, but there are no reports about its possible chemical effects on thephysiology of these filter-feeder organisms. This work seeks to obtain, with the use ofclassical methodologies, such as histology, and modern ones, such as metagenomics, thefirst reports of the effects of exposure to DEHP in the sponge Hymeniacidon Heliophila,at different biological levels.