Fast Feeder - The Frogfish - first published in the Nassau Guardian June 1981
little fish was slowly patrolling the edge of the reef,
picking at the tiny animals that form its food, when it
disappeared. One second it was there, and the next, it was
gone. All that remained was a disturbance in the water and a
slight movement from a weed covered brown rock.
brown rock is not a rock, nor is the fluttering shrimp-like
animal above it, a shrimp. The two constitute the obvious and
less obvious parts of one of the most highly adapted and
efficient predatory fish of the reef.
are seven species of frogfish or anglerfish in the Bahamas,
none of which grow very large. The smallest is the Smallspot
Frogfish, which attains a maximum size of two inches, while
the giant of the family the Ocellated (eyed) Frogfish, reaches
a mighty 15 inches.
frogfishes are masters of camouflage, their bodies squat,
lumpy and decorated with protuberances resembling weed, and
their colour - drab and irregular, mimicking precisely the
stones and rocks they inhabit.
foremost spine of the dorsal fin has moved forward, to the
upper lip and become amazingly modified to resemble a shrimp
or small fish, not only in its appearance, but also by its
strategy of the frogfish is to play a waiting game and
interest passers-by in its lure. When the curious fishes come
too close, the frogfish strikes. By expanding its mouth at an
incredible speed it creates a suction that engulfs its prey
before it knows what is happening. A frogfish can expand the
volume of its mouth by 12 times in less than six-thousandths
of a second, making it one of the fastest feeding vertebrates
known to science. Of course, in so doing, the fish swallows a
lot of water as well as its prey, but this is ejected as soon
as its supper is in its stomach. Movement of prey from the
mouth into the stomach is achieved in little more than time
than that required catching the prey in the first place.
fish also have the ability to ingest fish longer than
themselves. Like many deep-water predators, their mouths and
stomachs are gigantic in proportion to the rest of the animal.
most Bahamian frogfish are bottom-dwellers, the Sargassum Fish
(Histrio histrio) inhabits floating rafts of Sargassum weed.
Growing to a length of around six inches, it stalks its prey
in the weed rather than waiting for its prey to come to it,
relying on its superb cryptic colouration, and its ability to
propel itself by forcing water through the reduced gill
openings. The pectoral fins of the Sargassum fish are actually
prehensile, and can grasp strands of Sargassum weed like tiny
hands as it slowly makes its way through the Sargassum raft.
This species is not particular about its food and will even
consume members of its own kind. One dissected Sargassum Fish
held sixteen smaller Sargassum Fish in its stomach!
anglerfish eat other fish, although any shrimp that comes
within range is fair game. The Goosefish (Lophius americanus)
of North American waters grows to four feet in length and has
been reported to eat Seagulls and Cormorants – a not too
inconsiderable task in view of its huge mouth and fearsome
of us will ever see a frogfish in its own habitat, but boaters
may be interested in looking for the Sargassum fish. If a mass
of floating weed is netted
and shaken out into a bucket of water, a variety of
marvelously adapted Sargassum inhabitants can be observed.
Fish, crabs and shrimps all with the mottled brown colouration of the weed in which they live will appear.
the fish order Pediculati – the Frogfish and their kin, can
be seen some of the most amazing adaptations of the animal
world. From the greatest depths to the shallows of the reefs,
they lie in wait or cunningly stalk their supper, their
activities known only to themselves and to their bewildered
and unsuspecting prey - the latter for only the shortest time!.