When you watch scuba footage, it’s likely that much of what you see has been filmed during reef dives; this is no mistake, most people greatly enjoy reef dive sites, as these areas are often home to a wide array of marine life in various sizes, shapes, and colors. There are different types of reefs and in each type of reef you visit, you will encounter numerous unique species. Here, we’ll take a quick look at some of the most commonly encountered types of marine life.
Corals
There are thousands of coral species, both of the soft variety and the hard reef-building variety. Often mistaken for plants, corals are actually made up of thousands of tiny individual animals called polyps. They come in an endless array of colors and interesting shapes; some are tiny, while others are massive. Corals can be found throughout the world’s oceans, from the shallowest reefs to depths beyond 9,800 feet. Unfortunately, many coral species are in decline due to ocean acidification caused by global warming; toxic runoff, coral mining, and destructive fishing practices are also putting corals at risk. Protect corals while diving: do not touch them, snap off pieces for souvenirs, or use them to anchor yourself. By doing this, you won’t just be doing the corals and the millions of animals that depend on them for survival a favor; you will also be protecting yourself from injury since many coral species are capable of inflicting painful stings.
Sponges
Sponges live in concert with corals and though, like coral, they are sometimes mistaken for aquatic plants, they are actually animals belonging to the phylum porifera. These interesting creatures have bodies made up of a jelly-like pulp that is packed between two thin layers of cellular tissue. They have specialized cells that are capable of transferring nutrients between the inner gelatinous layer and the outer protective layers, and they are able to re-grow when injured. Sponges of various types can be found in both saltwater and freshwater environments, however there are many more marine species than there are freshwater species; in all, there are approximately ten thousand known sponge species, with some being found at depths beyond 8,500 feet. Sponges interact with other marine species, but they do so in a passive manner; small fish and other animals often take shelter inside sponges, and some animals including sea turtles enjoy feeding on them.
Starfish
Many people are surprised to discover that there are many different varieties of starfish in an intriguing array of colors, shapes, and patterns. These colorful little creatures are found in ocean environments worldwide, with various species inhabiting shallow reef environments and tide pools, and others living well beyond divers’ reach at depths beyond 6000 meters. Starfish are capable of utilizing various reproductive methods, and they are often capable of regenerating themselves after an injury. These amazing little creatures are usually harmless; crown of thorns starfish, however, eat coral and are causing serious damage to coral reefs worldwide. Crown of thorns starfish are toxic and will inflict a painful sting, as will some other starfish species. Protect yourself by never touching a starfish while diving.
Parrotfish
When diving, you may hear parrotfish nibbling on coral before you even see them; in fact, you can sometimes locate a parrotfish by following the sound of its munching. These beautiful fish come in various colors and sizes, ranging from 12 inches to over four feet in length at maturity. Found in tropical and subtropical regions, these fish are some of the most interesting reef dwellers, and they normally don’t mind being observed. With thick scales and strong parrot-like beaks that give them their name, they are equipped with stout pharyngeal teeth that grind rock and coral; an average parrotfish excretes up to ninety kilograms of sand annually. Watch for parrotfish on night dives; they have an interesting habit of secreting protective cocoons that allow them to sleep with less risk of predation.
Barracuda
Barracudas can often be encountered on reef dives, and different types of barracuda inhabit various sites around the world. These fish can be nearly two meters long, however they are quite slender; if you’ve ever seen a pike, you’ll note that the two species have a few things in common with one another. The barracuda has large, strong jaws and sturdy fang-like teeth that make grasping prey easy. With a pointed head, a soft white belly, and a silver body with a spotted or cross-barred pattern, this fish has five spins on its anterior fin and a single spine on its posterior fin. Its gill covers have no spines.
There are 27 different barracuda species. The fish are commonly encountered in the tropical and sub-tropical portions of the Atlantic and Mediterranean oceans, though they can be found in other places as well. They are efficient predators capable of swimming in fast bursts that have been clocked at as much as 27 miles per hour, sometimes pursuing prey that is larger than they are. While barracudas don’t normally attack people, they will bite if they mistake a diver for prey, or if they feel cornered or threatened in any way. When diving in areas where barracudas are common, avoid wearing anything shiny as this could provoke an attack; in addition, don’t pursue or try to pet a barracuda.
Groupers
Groupers are often quite large, and some species are capable of growing to the size of small cars. These docile fish are a favorite target of fishermen, which has caused their numbers to dwindle in past years. They are often interested by divers and some will approach and come close, hoping for handouts. Be careful if you are on a dive that encourages feeding groupers. Though they won’t harm you on purpose, these fish have very strong crushing jaws capable of smashing crabs and lobsters. Groupers like to hide in rocky dens and while you will often encounter them in colorful reef environments, you can often find them in areas where there are few corals.
These are just some of the animals you’ll find living in reef environments throughout the world. Some others to watch for include turtles, sharks and rays, crustaceans such as crabs and lobsters, and of course, colorful little reef fish like angelfish, anthias, Moorish idols, and others. Familiarize yourself with the animals you are likely to encounter at certain dive sites, and watching for the behaviors you have learned about will prove to keep you entertained for the duration of your dive. Remember – treat these animals with respect, and be sure to keep in mind that you’re a visitor in their environment: take only photos, and leave only bubbles.