New studies of barnacle sex sheds light on the evolution of genitalia. That is the focus of research being performed by Christopher Neufeld of the University of Alberta, Canada, and his colleague, Richard Palmer, of Palmer Labs. Barnacles absolutely can change the size and shape of their penises to suit their environment. When ocean waters are calm, barnacles have longer genitalia, when rough, they can make their members shorter and stouter.
“Barnacle penises are retractable… Read More: http://www.trendhunter.com/trends/barnacles-shaping-the-evolution-of-genitalia/