Postdoctoral investigator Gihong Park and Professor Hans Dam published a study in the Proceedings of the Royal Society B that demonstrates a fitness cost of defense in a red tide dinoflagellate. Organisms must defend themselves against their consumers. It has long been hypothesized that defenses such as toxin production may come at a cost in the form of reduced growth. Yet, demonstrating such costs of defense is challenging. Park and Dam’s study presents a novel approach using a growth-related gene to show that when a red tide dinoflagellate (phytoplankton) is exposed to a copepod grazer, it increases toxin production but decreases its growth gene marker, indicating a fitness cost of toxin production. While costly, the defense is adaptive because it lowers the consumer ingestion rate and it allows the dinoflagellate to persist. The findings have important implications for understanding the factors that control the rise and fall of red tide blooms. Such blooms plague coastal regions wreaking havoc on local fisheries economies and threatening public health.
Link to the paper: https://royalsocietypublishing.org/doi/10.1098/rspb.2020.2480