Getty Images / Wikimedia Commons Rights (collage)
Pubblico dominio, https://commons.wikimedia.org/w/index.php?curid=352698
By GerardM - http://en.wikipedia.org/wiki/Image:Dreissena_polymorpha.jpghttp://nl.wikipedia.org/wiki
Public Domain, https://commons.wikimedia.org/w/index.php?curid=352696