Medaka Fish (IMAGE) Duke University Caption These are Japanese medaka fish used in a new study that found microplastic fibers cause severe cell damage and possible hormonal changes. Fibers of polyester, polypropylene and other types of plastics are shed or washed off of synthetic textiles used in clothing and other consumer and industrial products, entering waterways. Credit Melissa Chernick, Duke University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.