Farming Fish: Parrotfish Harvest From Their Favorite Corals
Researchers find that Parrotfish essentially farm and harvest on their favorite algae spots. As farming fish, they're also enthusiastic in protecting their territory.
Strategic Algae Farmers
Researchers from the University of California Santa Barbara discovered something interesting about the feeding behavior of steephead parrotfish in two areas along the coral reefs of Palmyra Atoll in Hawaii. As it turns out, just like humans, steephead parrotfish have food preferences.
In the parrotfish's case, researchers observed that they seem to have favorite feeding spots in the coral reef. What's interesting is what they do in order to attain their favorite algae spots. Evidently, once a parrotfish has already finished the algae in his favorite spot, he moves on to his other preferred feeding spots in order to allow the algae to grow back. In turn, he could once again eat his favorite meal in the exact same area.
This results in a sort of rotating pattern in the parrotfish's behavior. It also shows how they are capable of essentially "farming" algae by letting it grow until they can harvest again. What's more, researchers also observed that the steephead parrotfish are also quite territorial when it comes to their favorite spots as they defend their territory from other parrotfish while waiting for the algae to grow back.
Coral And Algae Relationship
As it turns out, this behavior coming from the parrotfish is actually beneficial to the corals in the area. According to the researchers, turf algae can be harmful and even lethal to juvenile corals. By clearing patches of algae from the corals, parrotfish also allow pockets of space which allows tiny coral larvae to grow and thrive.
"Herbivores are really important for coral reef ecology because there's a constant battle between coral and algae. Anything that can remove algae is essentially considered a net positive for coral growth," said Peter Carlson, lead author of the study.
The authors also wrote a second study, this time observing the parrotfish's behavior in order to monitor their movement patterns through the years. They found that parrotfish travel over a kilometer offshore daily in order to spawn in sync with the tidal cycles. Further, they were also able to confirm the parrotfish's observed behavior from the first paper as the movement patterns showed a non-random and highly selective feeding behavior.
Parrotfish populations have greatly reduced in the wild in recent years due to overfishing. At the same time, coral reefs around the world have also been suffering. As such, researchers believe that it is important to observe the behavior of coral reef fish such as the parrotfish, as well as how they impact their habitats.
The papers are published in the Marine Ecology Progress Series.