Scuba diving with frogfish in Bali.
Have you ever heard the said so ugly so cute?
Frogfish, also known as anglerfish, is, for many divers, one of the favourite creatures to find underwater.
Even though some might call them ugly, weird or grumpy, they come in so many colours and variations they are just fascinating creatures.
Frogfish belong to the order Lophiiformes and suborder Antennarioidei. They are classified into two sub-families, which differ in their distribution and reproductive method.
One has a relatively small number of large eggs that are attached to the body during their development. The other spawn a mass of small eggs that immediately floats away in ocean currents to fend for themselves.
There are more than 46 known species of frogfish worldwide in tropical and temperate seas. Frogfish can live up to 20 years.
Why the name frogfish
Frogfish take their name from the fact that they do bear similarities to frogs!
They have unique pectoral fins, which have an “elbow-like” bend at the front and then just behind these they have smaller pelvic fins that resemble legs. This is common across all anglerfish species.
Frogfish are carnivores. They eat fish, crustaceans and even other frogfish.
Anglerfish do not have teeth (more like sandpaper jaws) and therefore have to swallow their prey whole.
A frogfish’s mouth can expand to 12 times their resting size and they have also extremely flexible stomachs.
This allows them to swallow prey up to twice their size. If they attempt to swallow prey which exceeds their abilities they are forced to spit it back out as they cannot chew it down into smaller pieces. A lucky escape for the potential meal.
The suction of the prey is the fastest amongst all fish. They can trap the pray in 0.006 seconds!
Frogfish love fishing!
All frogfish have a “lure” which is a fine antenna that stems from the top of the head and dangles a bait-like looking appendage directly in front of the frogfish to attract prey, hence the other common name “anglerfish”.
Different species have different lures that imitate different prey. Some have lures that resemble shrimp, others fish, worms, or tiny squids. Recent research has shown the striated frogfish’s lure to be bio-fluorescent.
The lure can re-grow if it is damaged or destroyed but might undergo a time of fasting until completion.
Masters of camouflage
Frogfish have the ability to “mimic” their surroundings in both form and color which makes them masters of camouflage.
In fact, they are so well camouflaged that when potential prey approaches they remain still, assured that they will not be spotted and they only move the lure to attract the prey closer and follow the potential “victim” with eye movement only. When the prey is within striking distance it doesn’t stand a chance!
Colour change it’s not instant like another species. It can take days and even weeks for a colour change to occur.
Many anglerfish can also grow hair and become ‘Hairy Frogfish’. It is not a species in itself!
Hunting the hunter
Despite their camouflage frogfish are not without predators of their own. For example, lizard-fish, scorpionfish, and other frogfish as well. While juvenile frogfish are snapped up with ease, once frogfish reach maturity they are generally the hunter, not the hunted.
Frogfish swim by jet propulsion
Frogfish spend long periods of being stationary, but they are a swimming species.
Because they lack a swim bladder, they use their modified pectoral fins to walk, or even gallop, across the sea floor. In order to “jump” the fish will suck in water through its mouth and then force it out through their gills. This makes them literally jet propelled!
Depending on the species, frogfish can produce between 40,000 to 180,000 eggs at one time.
Before the egg-laying, the abdomen of the female starts to swell as the eggs absorb water. This makes them slightly buoyant. The male begins to approach the female around two days before the spawning. During the mating process, the male nudges the female in the abdomen until she is ready and then the pair will swim up to the surface together where she releases her eggs which are attached to a buoyant mass of mucus which resembles a ribbon and is known as an epipelagic egg raft. Once the eggs are released the male fertilises them immediately.
After mating, the partners depart quickly to hide from predators.
When anglerfish first hatch as larvae, they look like miniature replicas of adults, but they have not yet to develop their lure. This happens later. Here in Bali we often find juveniles and they range in size from just 5 mm to 10 mm! Juveniles often display different coloration to mature frogfish. Did you know that the “clown” frogfish is actually a juvenile warty frogfish?
When they grow older, females are noticeably larger than males. The male anglerfish never grow much more than 1 cm while females can grow up sometimes as much as 1o times bigger.
Where can we see frogfish in Bali?
In Bali we see often many different species of frogfish all along the coastline. We see them in many different colours and sizes.
But if we have to choose our favourite spot to see these fish, it would be, no doubt, The Jetty in Candidasa. Actually, we call this dive site a frogfish paradise. We can find them perfectly camouflage in sea fans, sponges, rocks and even on the sand.
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