Caribbean coral reefs are home to hundreds of different types of fish, who vary from one another in size, color, patterning, shape, and behavior. Looking at an active coral reef can be mind-boggling at first, but it won’t take you long to see some order in the chaos.

One of the first fish likely to draw your eye is a parrotfish, a colorful, relatively large creature. Parrotfish get their name from their bright colors and also from their beak-like, fused teeth. They use their “beaks” to scrape algae from underwater surfaces, including rocks, pier pilings, and the occasional living coral.

There are more than a dozen varieties of parrotfish in the Caribbean, but in many species the appearance of the male is totally different from that of the female! The female stoplight parrotfish, for ­example, has a dark and light pattern of scales and a reddish belly. The male stoplight is mostly turquoise, with some yellow on the tail and no red at all.

"Learning the names of the fish – or at least the general group they’re in, such as eels, angelfish, jacks – enables you to learn more about them."

How is a budding fishwatcher supposed to figure it all out? I’m so glad you asked – that means it’s time to look into fish identification guides. There are water­proof guides you can actually take with you, but also books, and even references you can load onto your computer that will give you several different photographs or sketches of each fish. Although some people actually do carry their guides with them in the water, things are less cumbersome if you study the guide while out of the water – unless your waterproof guide is in the form of a human being!

The very shy trumpetfishOne of the most unusual-looking fish you’re likely to see is the trumpetfish, a long, skinny creature who, like the parrotfish, is named for its mouth: when a trumpetfish sucks down its small-fish prey, its mouth flares out in the shape of a trumpet. Trumpetfish of both sexes look the same; individuals can be brownish, reddish, vibrant purple or bright yellow.

One of the busiest fish you’ll see is the sergeant-major, especially the ones who have a blue coloration over their usual yellow, black, and white. These are the dads guarding their eggs from surgeonfish, wrasses, and other hungry critters. The eggs – tiny purple dots when first deposited – become greenish and finally grayish just before they hatch, as the eye of the tiny fish inside develops.

Learning the names of the fish – or at least the general group they’re in, such as eels, angelfish, jacks – enables you to learn more about them. For example, knowing that the big school of blue fish you spotted on your last dive were surgeonfish gives you a clue as to why they travel in such large groups. Surgeonfish are herbivores (algae-eaters), but most of the algae on and around a coral reef is the guarded garden of a damselfish. A large school enables surgeonfish to eat more than foraging individually would because, while the farmer damselfish are chasing some of the surgeonfish, the other surgeonfish are grazing.

Keep in mind that the fish we’re watching are wild creatures living in the natural world. Their lives revolve around finding food, avoiding being eaten, and reproducing. Once we know what we’re watching, we’re much more likely to recognize these basic behaviors, thereby enhancing our fishwatching experiences. The more you know, the more you see.

Snorkeling in St. MartinWhere are They?
These fish are just some of the striking creatures you’ll encounter in St. Maarten’s unique underwater world. Snorkelers will be pleased to know that many of the island’s reefs are close to shore. Home to grunts, parrotfish, and surgeonfish among other fish, they are also frequently visited by sea turtles, especially the southern and eastern sides of the ­island. Dawn Beach, Cay Bay, Mullet Beach, Little Bay Beach, and Maho Bay all offer good snorkeling, while a day on Îlet Pinel wouldn’t be com­plete without a few hours under water. Scuba divers, on the other hand, can venture much deeper, and deep is where you need to go to experience the haunting HMS Proselyte, which sank in 1801. The more recently-sunk freighter Tiegland is also alive with creatures.

Watch some of those magnificient species on our video channel: