Damselfish Aggressive & territorial creatures of the sea

We've been studying the bicolor, cocoa, and dusky (left to right) damselfish species in the Florida Keys.

Damselfish are classified as either farmers or nonfarmers based on their behavior towards coral and macroalgae.

The farming damselfishes cultivate the growth of macroalgae by biting off live tissue of coral. Common farming species in the Keys include: cocoa, dusky, and threespot (left to right).
The non-farming damselfishes graze on macroalgae and have not been seen harming coral. Common species in the Keys include: bicolor, beaugregory, longfin, and yellowtail (left to right, top to bottom).

We've been looking at bicolor, dusky, and cocoa damselfish aggression towards other herbivore reef fishes in the Florida Keys. These interactions may be indirectly influencing the reef by damselfish restricting the grazing of other herbivores. But is this a positive or negative influence on the reef?

Nearshore reefs have more turf and hard coral. Offshore reefs have more soft coral and more fleshy algae.
The number of encounters that each damselfish species met each intruder type depended on who the intruder is, who the resident damselfish species is, and the reef location.
The responses after encounters (aggression) varied by who the resident damselfish is and where they are located.


Overall, we have found that aggression is high between all three species of damselfish. However, we did see a significant difference in the aggression of our two farming species. The cocoa damselfish were more aggression toward other damselfish intruders, while the dusky damselfish were found to be more aggressive toward parrotfish intruders.


This research was permitted by the Florida Keys National Marine Sanctuary (permit # FKNMS-2013-077-A1). We would like to thank the Keys Marine Lab and the Conservation of Marine Resources Creative Inquiry Team. Funding for this experiment was provided by Clemson’s Creative Inquiry Initiative, the International Women’s Fishing Association, the Animal Behavior Society, the Women Diver’s Hall of Fame, and Sigma Xi. We would also like to thank Dr. Childress for his guidance, knowledge, and contribution throughout the years.


Created with images by Charles & Clint - "Damselfish"

Report Abuse

If you feel that this video content violates the Adobe Terms of Use, you may report this content by filling out this quick form.

To report a Copyright Violation, please follow Section 17 in the Terms of Use.