Scroll Top

Marine Species: Frogfish

It’s always a treat to see an expertly camouflaged frogfish on a dive. What makes these eccentric little fish so appealing?

The little frogfish, with its unusual name and even more unusual appearance, is a creature of expert camouflage. If you’re lucky enough to spot one (whose location wasn’t already known) on a dive, you’ll not only be amazed by its appearance, but you’ll also be held in high regard by your fellow divers, especially photographers.

What is a frogfish?

Frogfish, of the family Antennariidae, are a type of anglerfish, and are known as such in Australia and elsewhere. These are short and stocky fish, looking like the bodybuilders of the ocean. But unlike other fish, they do not have scales; rather, they have a textured exterior, sometimes covered in spinules and other appendages. Divers often mistake them for sponges due to their appearance. They can vary in size, shape and color, and can change their exterior to blend in perfectly with their surroundings. Their unusual, textured skin is to thank for their amazing, chameleon-like camouflage abilities, which they use both to protect themselves from predators and to help them lure in unsuspecting prey. In keeping with this camouflage, they typically move quite slowly, lying in wait for their prey. Only when their intended meal is close enough do they move rapidly, striking in as little as 6 milliseconds.

How did they get their name?

Frogfish (anglerfish) earned their name because of the way they hunt. They’re carnivores, dining on other fish and crustaceans, and have even been known to be cannibals. A frogfish’s mouth can expand to 12 times its resting size, enabling it to easily catch its prey. To attract passersby, the frogfish has a modified dorsal fin, featuring a retractable lure that resembles a shrimp. The fish uses the lure, like an angler, to draw its prey close. If eaten or damaged, the frogfish can easily regenerate a new lure. Once the prey is close enough, the frogfish grabs it much like a frog grabbing a nearby fly.

Where do they live?

Frogfish live in the tropical and subtropical regions of the Atlantic, Pacific and Indian Ocean and in the Red Sea. The Indo-Pacific region features the greatest diversity of species, with the highest concentration around Indonesia. Within the Lembeh Strait, divers have found nine different species. They generally live on the ocean floor around coral or rock reefs, but there are a few exceptions. The brackish-water frogfish is most at home in brackish and fresh water around river mouths.


What you may not know:

Frogfish lack a swim bladder, meaning that they use their short, modified pectoral fins to walk, or even gallop, across the seafloor. Juveniles can even use a kind of jet propulsion to move themselves by forcing their breath-water out through their gills, which propels them forward. The sargassum frogfish has adapted fins that can grab hold of strands of sargassum, enabling it to effectively “climb” through the seaweed.

So the next time you’re diving, if you’re lucky enough to spot a frogfish, know that it’s not as docile as it may appear and it is, in fact, using its remarkable camouflage to lure you in as well.

By guest author Beth Alexander