Moray Eels & Groupers: Teamwork in the Marine Environment

In Coiba National Park, we have the pleasure of observing several species of moray eel, an incredible hunter with a flexible body to move between rocks and wait in crevices for passing prey, a keen sense of smell, and not just one but two sets of jaws. While most fish avoid these clever predators, Groupers are known to actually seek them out, coordinating a team effort to hunt alongside them and share the catch.

Groupers themselves are expert hunters as well, with bursts of speed that make them formidable opponents. However, with their larger size and bulky shape, they are not able to catch prey that hide in small spaces and cracks. So, when their prey is not easy to reach, they seek out moray eels to flush them out instead.

First observed in 2006, this partnership has been studied by many scientists around the world. In the open ocean, Groupers are observed doing a sort of shimmying dance underwater to summon moray eels and signal their desire to hunt in a team. Occasionally, they even point out the hidden prey to a nearby eel by doing an underwater headstand, pointing out the fish’s hiding spot with their head and shimmying their body (check out this link to see a video of this behavior). This behavior is only done when there is a moray nearby, and is stopped as soon as an eel arrives. More rarely, when an eel ignores the signal, some have even witnessed Groupers fearlessly approaching the moray and attempting to push it toward the target prey.

Upon seeing the signal, the moray responds by chasing the fish out of its hiding spot to be captured in the speedy Grouper’s jaws. The two then actually share the meal, enjoying the rewards of their complimentary hunting strategies.

This sort of cooperation is one of a few examples of different fish species teaming up underwater to hunt, and there are many other manners in which marine organisms partner up for the mutual benefit of both parties. This sort of teamwork between the ocean’s many species goes to show how truly dynamic and complex life underwater can be, and how lucky we are to be witnessing some of this diversity here in Coiba National Park!

-By Daryll Carlson

Want to know more? Here you’ll find a great article with everything you need to know about eels!