The idea of symbiotic relationships is not new in the animal world. However, this article discusses the first time that one species chemically signals another species for help. Corals that are attacked by toxic seaweed release chemicals to signal fish (gobies) to swim over and fend off the invading seaweed. This process is remarkably fast. The gobies respond within a matter of minutes. Because the coral shields the gobies from predators and also provides them with food, it is not surprising that the fish take a very active interest in the well-being of their homestead. The article goes into the details of the research studies conducted and the results. I list the main take-home messages below:
– Coral experiments with goby bodyguards saw seaweed decline 30% over three days and coral damage decreased 70-80%.
– By collecting and transferring water samples from different places, researchers determined the fish do not respond to the actual seaweed, but to the coral’s signals.
– These 911 signals only come from specific types of coral.
– The chemical extract of the toxic seaweed is what causes the coral to signal for help.
– One species of goby actually eats the toxic seaweed, making the fish less attractive to predators. The other species of goby just spit the seaweed out.
I’m not sure how eating the seaweed would make the fish less attractive to predators. I wish they had elaborated on that a little more. The fish wouldn’t be able to re-emit the toxins because it would damage the coral, and I don’t think eating the seaweed would make the fish change colors somehow. I will look into that later. Back to the point of the article! These interactions are important for understanding marine ecosystems and how to preserve and restore them. The researchers also are hoping for a deeper understanding about the evolutionary journey of these fish and coral.