The Frogfish

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26.08.2015 11:08
Kategorie: News

Incredibly Fast "Suckers"

Frogfish sometimes looks as if they come from another planet. - © Karlheinz Grosch
Frogfish sometimes looks as if they come from another planet.
© Karlheinz Grosch

Finding a frogfish is the tough part. Once you do, taking photos of it is relatively easy, since they remain motionless in an attempt to evade detection. Looking at them, it is hard to imagine how this odd-looking sedate critter could be capable of the record-breaking speed at which they catch their prey.


How can I find a frogfish?
Who among us can spot a frogfish that doesn't want to be found? Not easy, eh? Well, that's the way it's supposed to  be! We may at times spot an eye or a fin amidst the background of the reef, and then realise that we've actually been looking at a frogfish. Yes, the frogfish is indeed a odd fellow, that disguising itself as a sea squirt, or just zoning out (or appearing to!) on the seabed trying to look as harmless as that familiar old shag pile in our living rooms.


A great video (shown at the San Diego Underwater Film Festival) depicts the frogfish in some fantastic sequences (from 0:38). This video provides a good insight into the locomotion and hunting methods of the frogfish. Thanks to Denise Glazer (Purple Twins) for her permission to post the video.



Information about the frogfish

Frogfish - © TomTom
A typical picture: This frogfish is supported by its pectoral fins.
© TomTom

No. of species: about 50 species
Family: Antennariidae
Length: up to 35cm
Habitat: Soil and reef
Appearance: Perfectly disguised and rather “unfish-like

Fishing for food: The frogfish is also called the anglerfish, thanks to its modified dorsal fin that's built like a fishing rod. At the end of it is a lure that looks like a shrimp or worm. The frogfish waves it around in a way that mirrors the movements of the bait, completing the enticing illusion for any unfortunate prey.

Six milliseconds to catch prey: 0.006 seconds. That's the incredible speed at which the frogfish can expand its mouth so that it creates a strong vacuum that sucks the unfortunate prey in. Once the prey is inside the stomach, the water that was also sucked in is then ejected. All this, in six-thousandth of a single second. Now, to call that a split second still doesn't quite do it justice.

Strolling through the reef In contrast, when moving to a new location, the frogfish prefers to crawl and climb around the reef using its pelvic fins. If danger strikes, it swiftly flees the scene by swimming away.

Two frogfish specimens from the deep  - © H.-C. Ho + Pietsch and Van Duzer (Wikimedia)
Two frogfish specimens from the deep - © left: Diceratiidae: Bufoceratias shaoi [Pietsch, Ho, and Chen, 101 mm SL, ASIZP 61796 (Photo by H.-C. Ho)]; right: Melanocetidae: Melanocetus eustales (Pietsch and Van Duzer, 93 mm SL, SIO 55-229) from Evolutionary History of anglerfishes (Wikipedia)


Epilogue
"Photographing frogfish isn't difficult; the tough part is finding them!”
Old saying among divers

Indeed, filming the frogfish as it catches prey is tough, due to the speed of the capture. By the time you start to press the shutter button, the prey would already be in the frogfish's tummy. Even with a flash sync speed of 1/60 second, it's still too slow!