Frogfish Behavior And Habitat

Frogfish Behavior And Habitat

Upon first glance, frogfishes appear to have faces that only their mothers could love. But it is an equally undeniable fact there is something that we find to be absolutely adorable in the way they look. And with the improbable twist of being so unattractive that with think of them as cute, there is little doubt that frogfishes have us hooked at first glance.

Worldwide there are approximately 50 species of frogfishes.  They are described in four families, with family Antennariidae containing the most species. Frogfishes are sometimes referred to as anglerfishes in reference to the lure-like appendage connected to the first ray of their dorsal fin. That ray is used to attract unsuspecting prey to within striking range in a manner similar to the way a fisherman might use a lure to help catch a fish.

Most frogfishes are relatively small animals with the body being less than seven inches long. However, there are exceptions such as the Commerson’s frogfish (Antennarius commerson), an animal that can be more than twice that long. This species is also known by the common name giant frogfish.

Frogfishes are known in all tropical and subtropical coastal waters of the world, and several species have been documented in temperate waters off Japan and southern Australia. They are typically associated with reef communities where these fishes live between near-surface waters to a depth of roughly 325 feet. The widely publicized Sargassumfish (Histrio histrio) is an exception, as this species lives in floating clumps of seaweed that are often found at the surface in the waters of the open sea.

Masters of camouflage

Masters of camouflage, frogfishes often adapt to look like the surrounding environment. As a result, they can be extremely difficult to spot when they are at rest as they often look like sponges, branches of corals or large clumps of encrusting algae. Some species actually cultivate bits of algae that grow on their bodies to help them in the art of camouflage. Collectively speaking, their colors range from white to vivid hues of oranges, yellows, reds and greens to black. Some fish are solid, others mottled, and still others are spotted. It is generally believed that the look of a given fish varies with the appearance of their surroundings and their “mood of the moment”. Their globular, somewhat humorous looking bodies are highlighted their small and upturned mouths.

While they are awkward swimmers, frogfishes are superb ambush predators. When “actively hunting” these clever predators remain almost perfectly still as they extend the “lure” that is connected to the almost invisible first ray of their dorsal fin. Once the lure is extended, the hunter wiggles it about to attract its prey, which is usually a small fish.

This lure typically consists of a lumpy, sometimes frilly-looking, globule. Where a human fishermen is somewhat blinded at the surface of the water, frogfishes have the ability to direct their lure towards their prey while following the action with their eyes. They also manipulate the lure to appear life-like, and with the already remarkably similar resemblance to animals such as worms, crustaceans, and fishes, the illusion is complete as the ploy often results in a successful baiting.

Scientists have videotaped the lightening speed at the moment of attack when a frogfish lunges at and engulfs its prey. The action takes place much too fast for human eyes to follow. As it makes its move a frogfish opens its suddenly enormous mouth as wide as it can as quickly as it can creating a pressure differential in the surrounding water. The “near vacuum” helps the fish suck in the surrounding water and the prey in an incredibly fast act. This feeding technique is known as “gape and suck,” and all the action occurs in less than 1/100th of a second! If lost, the lure can be regenerated, but that process is not a fast one.

Not Like Any Other Fish in The Sea

Frogfishes would win very few races in the world of fishes as stumpy tails propel their stocky bodies. They can also gain thrust by using jets of water squirted from their mouths. In addition, their pectoral and pelvic fins have evolved into “flattened hands” that frogfishes use to prop themselves when they rest and to assist them when they “walk” across the sea floor.

When moving across the bottom frogfishes can alternate the forward movement of their pectoral fins in a tetrapod-like walk, or they can move both pectorals forward at the same time, using the fins like humans use crutches to propel themselves sluggishly forward. In addition, the highly modified pelvic and pectoral fins are capable of grasping the surrounding substrate. This adaptation helps frogfishes hold still as they attempt to ambush their prey even in areas where there is current and surge.

The Rare Sighting of A Frogfish

While finding a frogfish for the first time is certainly challenging, many specimens can often be seen for days, or even months, on end as they remain in a small physical area. And if they are not where they are expected to be, they often move only a few inches to a few feet from their previous location. If disturbed, frogfishes often turn and face away from intruding divers rather than swim away.