A Blue View: Masters of Disguise
Published September 11, 2013
A Blue View is a weekly perspective on the life aquatic, hosted by National Aquarium CEO John Racanelli.
From the smallest plants and animals invisible to the human eye to entire ecosystems, every living thing depends on and is intricately linked by water.
Tune in to 88.1 WYPR every Tuesday at 5:45 p.m. as John brings to the surface important issues and fascinating discoveries making waves in the world today.
September 11, 2013: Masters of Disguise - Marine Animal Camouflage
Click here to listen to John discuss how essential
camouflage is to the survival of many marine species!
This world of ours can be a dangerous place—and for many undersea creatures, camouflage means the difference between life and death. In some cases, it’s a strategy for defense against predators; in others, it enhances their pursuit of prey. One thing’s certain: a good camouflage can be an effective way to survive and thrive in the sea.
Take the ornate wobbegong, for example. This unique shark species is the opposite of eye-catching. Blending easily with the sea floor, a wobbegong can flatten its body, while spots and patterns resemble coral and rock. Skin flaps under its chin appear like seaweed, luring prey toward the shark’s mouth.
Other species employ different strategies. The double-ended pipe fish is actually able to emulate the swaying motion of sea grass. Decorator crabs adorn their shells with items from the sea floor to mimic their surroundings, often clothing themselves in sponges and seaweed. Peacock flounder settle into sandy bottoms appearing as one with the ocean floor. In laboratory tests, this fish has proven itself capable of matching striped, polka-dot and checkerboard flooring virtually instantaneously.
The camouflaging capabilities of ocean creatures take many different forms. A particular coloration may help an animal blend into its environment. Patterns can allow some creatures to better hide. Others may have the ability to morph their bodies into a particular color, shape, or texture to fool predators. And some animals can move in a distinctive way—or appear very still—in an effort to avoid detection.
Cephalopods, which include squids, octopuses, and cuttlefish, are the ultimate masters of disguise. Some species show 30 to 50 different appearances and can use every camouflaging strategy to maximum effect.
Scientists are still trying to understand the full scope of what these aquatic animals are capable of. Remarkably, octopus-like cuttlefish are able to rapidly adapt their body patterns and coloration—yet they are in fact colorblind. What’s clear is that some of these sea creatures are far more sophisticated in their use of camouflage than scientists currently understand, and this area of study is rapidly evolving.
A recent article in Current Biology examined the color-changing capabilities of the octopus and squid. Researchers found that some species can actually become transparent as they swim along the ocean’s surface, helping them avoid hungry predators. But in deeper waters, they can adopt a different behavior—turning red.
At depths below 2,600 feet, that same transparency that is so helpful along the surface actually becomes a liability, when light reflects off the transparent beings. Instead, it is more effective to be red, as red is the first color to lose visibility in deeper water, allowing creatures to become virtually invisible, albeit in a different way.
Some animals have different strategies for camouflage depending on the conditions they find themselves in. Exactly how these animals are able to interpret those conditions, and then change their appearance as a result, is still unknown.
As research on these animals and their amazing capacity for camouflage continues, a search for terrestrial applications is underway. Roger Hanlon, a senior scientist at the Marine Biological Laboratory in Woods Hole, Massachusetts, and a leading expert on marine animal camouflage, is collaborating with engineers across the country to develop a material that mimics this camouflage capability. The hope is that their research with cuttlefish may hold the key to creating new kinds of camouflage for clothes, buildings and vehicles.