May 062010
HomeCaribbean Sea and Gulf of Mexico
HabitatTropical seas (reefs and shallows)
NicheAmbush predator
Favorite Food – small fish like wrasses
Lengthup to 3 feet
Statuslocally common

Among the residents of the warm waters of the Caribbean, trumpetfish are both conspicuous and anything but. Relatives of seahorses and pipefish, their flattened tube-like bodies are truly bizarre to behold, provided you can find them. Most of their lives are spent hiding on the seafloor or drifting in the currents as inconspicuous as a piece of seaweed.

Trumpetfish are ambush predators, using stealth are trickery to remain unseen until the moment of strike. They often hover vertically alongside sponges, thin corals, and gorgonian weeds, swaying in tune with the currents. Other times they’ll swim alongside large fish in order to cloak themselves from schools of wrasses on the other side. If an unsuspecting fish gets too close, the trumpetfish will dart at it, flaring its mouth open like the end of a trumpet. Like other fish that hunt by ambush, they suck in a volume of water with lightning speed during an attack, vacuuming small fishes into their mouths.

Trumpetfish are still locally common in many parts of the Caribbean and Gulf of Mexico, but like any resident of a reef system, they’re vulnerable to even slight disruptions. Something like a giant oil slick could have unwelcome consequences for these and thousands of other species living in the warm waters off the Americas.

*filmstrip photo provided courtesy of JennyHuang on Flickr Creative Commons

Jan 172010
photo provided courtesy of 3Neus on Flickr Creative CommonsHometemperate and tropical seas worldwide
Habitatocean surface
Nichepassive predator
Favorite Foodsmall fish
Lengthup to 100 feet
Notable Featurethe whole is composed of thousands of individual organisms

Although it looks like a jellyfish, the Portuguese Man-o-War is actually a colony of living organisms that band together to form a highly efficient killing machine. These organisms, called polyps, each perform a specialized role in order to keep the whole outfit floating, killing, eating, digesting, and reproducing in the world’s oceans.

The Portuguese Man-o-War is so named because of the projection on its float bladder that resembles the sail of a centuries-old warship. This sail catches wind on the surface of the ocean, which is the only way the colony can move. The Man-o-War has no means of locomotion and can only float. It’s at the mercy of the sea breeze and ocean currents, and if either of these forces drives it onto the seashore, it’s done for. However, as long as it remains at sea, it is a formidable predator.

Although it’s not technically a jellyfish, the Portuguese Man-o-War nonetheless hunts like one. It boasts dozens of dark purple tentacles that can trail behind the bladder in the water for over 60 feet. Like a net trolling behind a boat, these tentacles are used to kill and ensnare prey. Each one is studded with tiny cellular weapons called nematocysts. Each contains a trigger mechanism, a coiled spring, and a deadly barb. When an unsuspecting fish brushes up against one of the Portuguese Man-o-War’s tentacles, it flicks the trigger and the trap is sprung. The coiled spring unfurls in a fraction of a second, driving the venomous barb deep into the fish’s body at high velocity. Toxins in the barb attack the fish’s nervous system, paralyzing it. The polyps specializing in digestion take over, secreting powerful enzymes to break down the fish for the good of the colony.

Although it can’t run, fly, or even swim, the Portuguese Man-o-War is nonetheless one of the most feared hunters in the temperate and tropical seas of earth, delivering stings powerful enough to land an unwary diver in agony. They are also prime examples of the fascinating possibilities of working together in the natural world.

Jan 142010
photo provided courtesy of Mister.Tee on Flickr Creative CommonsHomeIndo-Pacific Oceans
Habitatcoral reefs, rocky coastal shelves
Nicheambush predator
Favorite Foodsmall fish
Lengthup to two feet
Threatshabitat destruction, exotic fish trade, bottom trolling fishing practices
Notable Featurehighly venomous

The estuarine stonefish is one of five species of synanceia, a group of unusual scale-less fishes that inhabit tropical waters. However, this species is commonly known just as the stonefish. These grotesque fish are both masters of camouflage and killing in their underwater lair.

Stonefish are the most venomous fish in the world, delivering a powerful toxin through sharp spines on their dorsal fins. What makes the stonefish so terrifying is that it’s nearly impossible to see when it’s sitting motionless on the sea floor. As an ambush predator, it relies on its ability to blend in with its surroundings. Many divers have discovered the sinister nature of this fish the hard way, in excruciating pain after stepping on what they thought was a stone. If the antivenin is not promptly administered to reverse the effects of the deadly toxin, what started as an unfortunate accident could quickly turn fatal.

Stonefish don’t use their venom for hunting because they don’t need it. Few fish even know of a stonefish’s presence before they’re gobbled up. The stonefish has eyes set on the top of its head, so it can remain completely motionless piled in sand and mud until its victim is practically touching its body. It then strikes with lightning speed, sucking the unfortunate fish into its huge mouth.

Although stonefish encounters can prove deadly, the number of those encounters in the wild is steadily decreasing. Destruction of their rocky reef habitats, collection as exotic aquarium fish, and bottom trolling fishing has devastated populations in the South Pacific. They are now an endangered species.