An ocellated wrasse collects algae for a nest.UNIVERSITY OF PALERMO, NATASCIA TAMBURELLOHow fish will respond as global carbon dioxide (CO2) emissions climb and the oceans become more acidic remains an open question. Previous studies have shown that some fish can show altered sensory behaviors in acidified waters. Now, for the first time, scientists have found that some fish also change their reproductive behaviors in CO2-rich, acidified waters. Their results appeared today (July 26) in Proceedings of the Royal Society B.
Researchers from the University of Plymouth, U.K., and the University of Palermo, Italy, studied the ocellated wrasse (Symphodus ocellatus), a Mediterranean, rocky subtidal fish that lives—among other places—near natural CO2 seeps off Italy’s Vulcano Island.
These fish have intricate reproductive behavior, with three kinds of males vying for access to a female’s eggs. There are dominant males (who build nests, court females into the nest, and defend the dwelling), satellite males (who help dominants in courting and defense), and sneakers (who try to slip into the nest to join spawning females). (See “Sly Guys,” The Scientist, July 2014.)
To investigate reproductive behavior, the researchers shot one 10-minute video for each of 18 nests in acidic waters and 14 nests in ambient waters. They observed that ...
