Otolith (image) University of Washington Share Print E-Mail Caption This otolith has been extracted from a fish. It is still within its fluid sac which is surrounded on the outside by blood vessels. Otoliths help fish with hearing and balance. Credit Sean Brennan, U of Washington Usage Restrictions Photo credit required. Share Print E-Mail 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.