Mariner - Spring 2008 - (Page 12)

Some juveniles have special “baby clothes” reserved for their youth. Others wear their less-conspicuous pajamas to bed each night. Some even have false eyes (not just eyelashes) on their bodies to ward oﬀ attack. And some can pull a superhero-like quick-change without the aid of a phone booth. But why do the fish of the Great Barrier Reef have such amazing and diverse attire? There are almost as many reasons as there are fish in the sea. Even if you’ve never been to Oz, odds are you’ve heard of the Great Barrier Reef. Lying oﬀ the east coast of Australia, it covers an area half the size of Texas and is the only living organism that can be seen from outer space. Not only that, it contains more species of fish than any other marine habitat—close to 2,000 of them in an astounding array of scarlet, rose, yellow, turquoise and emerald. What led to this wild extravagance? To unravel the mystery you have to think like a fish. A ﬁsh-eye view They may dazzle the human eye, but in the complexity of a coral reef, it’s possible these kitsch colors serve as the perfect camouflage. Human eyesight can distinguish many shades of yellow and green, but according to the latest research, a reef fish would be hard-pressed to tell a banana from a lime. Fish eyesight does however pick out fine distinctions in shades of blue-green. So if you put on fish glasses, the yellow of a trumpetfish swimming 10 feet away blends into the reef behind it, while the light blue of an angelfish’s stripes blends into the hazy blue of open water. And red actually disappears upon descending into the depths. Science is also revealing that only some fish (maybe half) can see ultraviolet light. Small species, like damselfish, are more likely to perceive UV than big, fast-moving predators, and UV can only be seen up close. So those UV spots on a two-bar damselfish may be visible to its pals but not to its enemies. Protecting their assets Color isn’t the only way fish camouflage themselves. Butterflyfish usually have a dark band covering the eye, and a false eye spot on or near the tail. As they frequently feed with their heads poked down a hole, their rears are left vulnerable. The false eye may oﬀer them some protection against predators. The juvenile rockmover wrasse looks and acts like drifting debris—pretty unappetizing to a hungry barracuda. Another has a flip-flop swimming style that is thought to mimic a foul-tasting flatworm. It pays to advertise Color can also say, “Hey, look at me!” Several species of cleaners, fish that nibble the parasites oﬀ other fish, share a similar shade of blue whether or not �hasin� �ain�ows: Fish of the Great Barrier Reef 12 Holland America Line

Table of Contents Feed for the Digital Edition of Mariner - Spring 2008

Mariner - Spring 2008 Table of Contents Black Pearls of the Sea of Cortez St. Lucia’s Drive-in Volcano Alaska’s Prolific Wildlife How Coffee Changed Costa Rica A Traveler’s Guide to Holiday Shopping Malta’s Last Stand Colorful Residents of the Great Barrier Reef Introducing Our New Website, a New Mariner Society® Director, a Face-lift for the Ms Prinsendam and More The Best Cruise Fares Currently Available The Ms Eurodam’s New Tamarind Restaurant Your Guide to Holland America Line Savings 2008/2009 Sailing Schedule

Mariner - Spring 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.