Shedd's Masters of Disguise
Every Halloween, we don costumes and become someone (or something) else. But when the night is over, we hang our costumes in the closet and wipe off the last stubborn streak of face paint, once again ourselves. For some animals at Shedd, disguises are not a once-a-year event: They are a lifestyle.
This Halloween, we profile some of Shedd’s greatest masters of disguise.
These animals may have eluded you during your visit to the aquarium. At times,
when you think an animal is off exhibit or “just not around,” it is hiding in
Let’s begin with our first aquatic Zelig, the weedy scorpionfish (Rhinopias frondosa). You may have mistaken the weedy scorpionfish for seaweed or debris. Not only is its body mottled green or yellow, but its tail, fins and spine also have leaf-like strands. When the scorpionfish moves, its weedy appendages fan out like an underwater accordion.
The scorpionfish disguises itself to catch food. As it hides, it remains motionless until a small fish approaches—sometimes waiting for days or weeks! Then, in a split-second, the scorpionfish snatches its meal. The weedy scorpionfish can also stalk fishes by folding itself into different shapes or by swaying back and forth on the seafloor to mimic seaweed. Using these techniques, the scorpionfish can move closer to its prey without attracting attention.
But even the most concealed animals need protection. The weedy scorpionfish gets the second part of its name from the venomous spines along its back. Get too close to its hiding spot and the scorpionfish will defend itself with these lethal barbs.
The weedy scorpionfish is found at depths of 33 to 965 feet in waters near Australia, Japan and Africa. Even in our Wild Reed exhibit, it may be too well-disguised for you to find.
Our second animal master of disguise is the mata mata turtle (Chelus fimbriatus). The mata mata’s disappearing act is simple: It disguises itself as a pile of sodden plant debris. With a lumpy, moss-coated shell, this turtle sits still on the river bottom all day long. As it waits, the mata mata occasionally stretches its lengthy, muscular neck to the surface of the water to breathe.
The mata mata has a triangular, leaf-shaped head with a snorkel-like snout. As if that wasn’t strange enough, it also has mottled tufts of skin on its neck that keep it camouflaged even when it moves— although it mostly stays motionless. To catch prey, this turtle suddenly opens its mouth underwater and fish rush in with the current. Unlike other turtles, the mata mata is unable to chew and relies on its vacuum-like mouth.
Given its feeding behavior, the mata mata is a poor swimmer and prefers walking along the river bottom, if at all. Its unique appearance is captured by its Latin name, which means “fringed turtle,” though one scientist characterized the turtle even further, calling it “the vision of a disordered dream.”
The nature of the mata mata has long confused scientists. Besides the fact that it was renamed 14 times before the name Chelus fimbriata was finalized, it is also the only animal in its genus. Although the mata mata is native to the Amazon and Orinoco river basins, you can visit the Amazon Rising exhibit and search for it on the flooded forest floor. (Hint: It’s with the caimans.)
Our final illusionist, the lookdown (Selene vomer), is a flashy fish. At first, the lookdown’s silvery skin may not seem like much of a disguise. But don’t let its showy appearance deceive you. The lookdown has a flat, rhombus-shaped body and a severe forehead. It rarely swims alone, but when it does you can see its long, shiny fins.
Lookdowns don’t just swim together to socialize: Staying in groups confuses their predators. In fact, a lookdown not only disguises itself within the crowd, but also changes color to match the surrounding sea life. It does this by manipulating the reflection of light on its shimmery skin. Instead of hiding behind objects or camouflaging themselves as coral, lookdowns can blend into the water itself and hide in open ocean. When they move as a group, they look like a blue ocean current.
Finding a lookdown in the aquarium is much easier than in the Atlantic Ocean, but check them out anyway. The ability of their flashy camouflage will surprise you.
Can you match these disguises on Halloween?
—Nadia Hlebowitsh, web team