For years I’ve been seeing this interesting behavior between certain species of grunts. And for years I’ve been trying to capture it on film and I finally hit pay dirt! Luckily, I had a GoPro on me and in standby mode. As soon as I saw these two white grunts (Haemulon plumierii) facing each other with their mouths open, I started rolling. Got it!

Grunts in the Giant Ocean Tank

We have 12 different species of grunts in the Giant Ocean Tank. I’ve seen this behavior among three of them, including French grunts, bluestriped grunts, and—as you can see in this video—white grunts.

Why do they do this? According to … “Frequently exhibit a ‘territorial’ kissing display in which two contenders push each other on the lips with their mouths wide open.” Other theories suggest that it’s a dominance thing.

In other news

Why is a grunt called a grunt? Simple – grunts make grunting sounds! The sounds are produced when teeth grinding deep within the throat are amplified by the air bladder. Grunt!