Orange Frogfish
- Clown Frogfish
Frogfish, or known as Anglerfish to my Aussie friends, are a diver’s delight. Small frogfish prefer shallow water, hiding in crevices, between corals, and among the rubble. Their expert camouflage makes them very difficult to spot. In my group of diver friends, an alcohol beverage of choice (after diving is done for the day of course) is a common reward for being the lucky spotter. I have heard grown men squeal out loud underwater and bang endlessly on their tanks in excitement, to call the other divers to the find. Oh how such a small ugly fish can excite us all.
Painted Frogfish
Shallow water Frogfish display cryptic behavior, with body shapes and varied colors that help them mimic their environment resembling the coral, sponges, and algae that they perch upon. Adult sizes vary from 10 to 38 cm. Because they often reside in the same area for months at a time, divers are able to visit an individual during many dives. While I was in Indonesia diving for a few weeks in the Bunaken Marine Park, I was able to visit a Clown Frogfish several times. Species can be many different colors, from black to red, orange, yellow, browns, white, purple, green, and some even have blue patches. They can change their colors as quickly as a matter of days, or over a period of weeks to mimic objects in their immediate vicinity. If they move to darker surroundings, their bodies will adapt and change darker as well. They even can adapt their skin to resemble the openings of sponges or the apertures of sea squirts.
The Frogfish is a fascinating fish in that it looks like a cross between prehistoric life and evolution from sea animals to land animals. They are stocky, round fish, with pectoral fins resembling an elbow joint, and small round uncovered gill openings located behind the fins, with a very large upward directed mouth. They have small tails and large heads. The modified pectoral fins look like small feet including toes. Because Frogfish lack swim bladders, (except the Sargassum Frogfish), they walk using their pectoral fins. Most Frogfish use a gas bladder to control their buoyancy. They use their tail fin to help them swim but mostly rely on a form of jet propulsion for swimming. Frogfish will rhythmically suck in large amounts of water through their mouth and force it out through their small gill openings, which are located behind their pelvic fins by the tail. Most Frogfish remain stationary, relying on their expert camouflage to both hide from predators and to hunt for food. They prefer to lie and wait for their prey to approach, except for the hairy Frogfish which will walk along the bottom. They have two kinds of gaits, one where they alternately move their pectoral fins forward leaving their pelvic fins out resembling a tripod, and the other like a slow gallop where they move their pectoral fins simultaneously forward and back transferring their weight to the pelvic fins while moving the pectorals forward. Either way, they can only cover a short distance. The Frogfish is a master of camouflage with a body often covered with warts, skin flaps, spots, filaments, or stripes. Other examples of camouflage adaptation include those that look like plants like Sargassum weeds, sponges including openings they imitate with spots on their skin, and sea squirts. Some Frogfish are covered with algae of hydrozoa, their camouflage so perfect that sea slugs have been known to crawl over the fish without recognizing them. There is even a striped Frogfish which resembles patterns found on stony corals. Frogfish rely on this camouflage to protect them from predators. Most predators have a hard time distinguishing them from the surrounding habitat unless they move. If they are spotted, frogfish are able to suck in water and puff up their bodies, making them hard for predators to swallow. Because of this aggressive mimicry and its feeding behaviors, frogfish are one of nature’s most highly evolved examples of lie-in-wait predation.
Painted Frogfish Fishing (Black Phase)
Painted Frogfish Pair
Unlike passive predators that lie in wait such scorpionfish and sand divers, the frogfish lure in its victims to be captured. The first dorsal spine has been modified to moveable fishing rod or luring apparatus called an illicium. It is tipped with a flesh like lure called esca. The rod is different lengths for different species of Frogfish. Its third dorsal fin is greatly enlarged. The lure often mimics a small animal. Depending on the Frogfish species, the esca can resemble a worm; look like a shrimp, or even like a small fish with an eye-spot and appendages resembling fins. When using his lure, a Frogfish will imitate the way which that particular animal would move. This type of mimicry to catch its prey is called aggressive mimicry. I find it most fascinating that not only does a Frogfish rely on camouflage but also the way in which he attracts its prey using his lure as a “fishing pole.” Most other predator fish lie in wait for other fish to swim close to its mouth, but the Frogfish lures its prey in to where he can actively strike. The prey approaches the mimicked food and is swallowed. Frogfish eat mainly fish, shrimp, crabs, and even each other. They can swallow prey twice their size. When potential prey is spotted, a Frogfish will follow it with its eyes, and when it approaches within about seven body-lengths, the Frogfish will move its lure mimicking the animal it resembles. As the prey approaches, the Frogfish will slowly move itself to prepare for the attack, sometimes approaching or stalking. Sometimes he is just simply adjusting the angle of his mouth. Luring techniques depend on the surroundings in which the Frogfish lives. A Frogfish living on the sand or muck bottom would have a lure close to the ground trying to entice bottom dwellers out of their holes. A Frogfish living in a crevice would have a smaller lure, more like a white ball, stretched in front of its head. A Frogfish living exposed on coral or sponges will have a lure above its head with a longer lure to entice fish to come closer. Each Frogfish species moves his rod and lure in a special pattern to attract the attention of its potential prey. The catch is made by the sudden opening or unhinging of its jaws which enlarges the volume of the mouth cavity as much as twelvefold. This pulls the prey into the mouth along with water causing a vacuum effect, the water flowing out its gills. While the prey is swallowed, the esophagus is closed with a special muscle, keeping the victim from escaping. In addition to expanding their mouths, they also expand their stomachs to swallow animals as much as twice their size. This happens so fast that other animals don’t even see it happen. Frogfish have been seen eating lionfish, with the poison from the lionfish seeming to have no effect on the Frogfish. Frogfish appear slow, but can attack in as little as 1/6000 of a second, making the fastest movement in all of the animal kingdom.
Because the lure (esca) acts like bait, which is highly susceptible to loss or damage by attacks or the nibbling of potential prey as well as predators, some Frogfish have a pocket-like aperture formed by the membrane between the second and third dorsal spine which is used to protect the lure. Frogfish can regenerate their lure, but might undergo a fasting period until the re-growth is completed, which can take four to six months.
Un-named Frogfish
The eggs are very small, as .02-.04 inches and adhere in a gelatinous mass, or long ribbon. For most species, the eggs drift on the surface. After two to five days, the fish hatch and the newly hatched alevin are between .03 and .07 inches. For the first few days they live on the yolk sack while their digestive systems continue to develop. The young have long fin filaments and resemble tiny tenacled jellyfish. For one to two months, they live as plankton. After this stage and at a length of .6-1.1 inches, they have the shape of an adult Frogfish and begin their lives on the sea floor. Young frogfish will often mimic the coloration of poisonous sea slugs or flatworms for
There are currently about 48 known species of Frogfish. Because are oceans continue to be explored, new species of marine life are still being discovered. While I was in the Raja Ampat area diving, I took photographs of two kinds of frogfish that I am waiting for an expert to identify, as I am unable to identify them. These unique fish are such as delight to find, much like your first love, you will remember your first frogfish discovery. Happy Hunting!
Giant Frogfish
I had the privilege of observing a fox family for a few days in the early April. The mom made her den near Lake Michigan at the top of a hill, in a heavily populated area. They are an attractive animal with a rusty reddish body, white underpants, chin, and throat, and a long bushy tail with a white tip. They have prominent pointed ears. The backs of ears, lower legs, and feet are black. The distinguishing feature which sets them apart from all other fox species is the white-tipped tail. Their average height is 15-16” tall, 35-41” long and weigh between 8 and 15 pounds.
