This little lemon-yellow beauty is a juvenile Commerson’s frogfish. Frogfish are rarely seen by snorkelers because they blend in so beautifully. Typically they look like bits of the reef but some, such as this one, mimic sponges and so are more easily seen.
Frogfish are anglers. They sit motionless on the bottom. When potential prey approaches, they flick their first dorsal fin forward. This is tipped with a fleshy lure that hangs over its mouth. If the prey takes the bait, the frogfish strikes. It can expand its mouth to swallow quite large fish and it strikes with such speed that other fish in the vicinity are generally unaware what’s happened, thus allowing the frogfish to remain in place and continue fishing.
In this photo, the frogfish’s eyes and mouth are visible, as are its pectoral fins that are adapted to help it hang on to the reef and to move about.
This frogfish was spotted by my wife and we watched it for a while before we were interrupted by three whales breaching. They were half-a-mile or more away, but this was the first time I’d seen whale activity from the water and it was pretty impressive, if almost impossible to photograph.
When the whales settled down, I dipped my head below the water to try and locate the frogfish again and the first thing I saw was a white-tipped reef shark cruising by. I suspect it had been attracted by my feeble attempts to dive and photograph the frogfish, probably thinking there was some easy prey to be had. It quickly disappeared again, but it made for a memorable few minutes.