Omilu, the bluefin trevally, gets quite large and is one of the top predator fish on the Hawaiian coral reef and it often hunts small fish along with puhi the moray eel.
One would think that the large 2-foot long trevally would eat a smaller moray eel but in Hawai‘i that is not the case. When I scuba dive in Palau and Tahiti, I have seen large trevally eat small moray eels and the eels are quite rare as most of them get eaten before they mature into adults.
Hawai‘i has more moray eels then any reef system I have seen worldwide. I have always wondered why, and then I saw something amazing happen at Koloa Landing in Kaua‘i that gave me the answer to my question.
I was following and shooting video of a 15-inch papio (young trevally) that was darting around the reef trying to catch small fish with little success then a small whitemouth moray (puhi ‘oni‘o) poked its head out of a hole and looked around. The papio immediately darted over to the moray and I thought it was going to try and eat it, but something totally different happened.
The two fish greeted each other with what looked like a kiss. After the kind introduction the moray turned around and went back into its hole in the reef, and the papio started a zigzag pattern above the reef. Within a few minutes the moray scared a small fish out of its hole in the reef and the papio gobbled it down. This was amazing to watch, as it was obvious that the two different fish species were hunting together.
After a while, the papio chased a small fish on top of the reef down into a hole, then the moray grabbed and ate that fish. After both the eel and papio had a meal they once again rubbed noses and took off in different directions.
I was so happy to capture this hunting behavior and share it with the local divers, who said they have also seen this pair of fish hunt together so this was a regular routine, not just a rare one of a kind encounter.
Fish helping other fish to hunt is quite common. After seeing the puhi and papio hunt together at Koloa Landing, I started paying attention to this type of behavior.
I have now shot video of roi hunting with the eels, barracuda hunting with the eels and in the Philippines, I have video of a sea snake hunting with a large omilu! I guess if you are a moray eel and want to survive in Hawai‘i, you may just want to help feed the larger predator fish so you don’t become food for the predators. Fish may just be a lot smarter than they look!
You can see the papio hunting with the puhi in my movie The Marine Life of Koloa Landing up on my webpage at www.underwater2web.com and YouTube at Underwater2web. I will have a full movie out soon about fish hunting together and if you subscribe to my YouTube page, you will get it first.
Terry Lilley is a marine biologist living in Hanalei Kaua‘i and co-founder of Reef Guardians Hawai‘i, a nonprofit on a mission to provide education and resources to protect the coral reef. To donate to Reef Guardians Hawaii go to www.reefguardianshawaii.org.
Source: The Garden Island