Parasitic Isopod (IMAGE) University of California - Santa Barbara Caption This parasitic isopod, which is related to rolley pollies, is one of the larger parasites encountered by the researchers in the estuaries. The isopod is almost one centimeter long, and was found infecting a crab, which it had "parasitically castrated," completely blocking the host's reproduction. Credit Ryan Hechinger 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.