Do parasites know where the grunion go?
by Dr. Bruno Passarelli, Saddleback College
The California grunion, Leuresthes tenuis, is a beach-spawning fish endemic to California, U.S.A., and Baja California, Mexico. Southern California sandy beaches, crucial for grunion reproduction, have been continuously impacted for the last several decades due to high levels of urbanization, coastal construction, beach grooming, and pollution. Metazoan parasites can be used to study many aspects related to the ecology of their hosts, including movement patterns. In this study, California grunion were collected at five localities in the Southern California Bight (SCB) between 2016 and 2018 and inspected for parasites. A total of 2,902 parasites belonging to 26 taxa were identified and quantitative descriptors were calculated for each taxon. Overall, 84.6% of grunion were infected with at least one species of parasite and, on average, 3.8 parasites were found per infected fish. Analysis of parasite communities showed that the metazoan parasite fauna of California grunion varies among localities within the SCB. This variation in parasite assemblages is greater than what would be expected in freely migrating fish. This suggests that groups of California grunion may stay relatively close to their spawning grounds instead of moving extensively across their range in the SCB.
Dr. Bruno Passarelli is a professor at the Department of Biological Sciences at Saddleback College in Mission Viejo, California. He has earned an A.A. degree in General Science from Santa Monica College, a B.Sc. in Marine Biology and a M.Sc. in Biology from CSU Long Beach, and a Ph.D. in Biology from UCLA. Dr. Passarelli has been teaching a variety of courses at Saddleback College since 2011. These courses include Marine Biology, Coastal Ecology, Evolution, and Oceanography. He has also been leading study abroad programs to Brazil and Costa Rica since 2015. His research interests include marine invasive species and marine parasites, especially the ones associated with marine fishes.
Tickets are available HERE.
Parking is $1 per hour, but FREE for members - become a member today!