SSI - Your choice for certification

Catfish is the common name given to any fish in the order Siluriformes and are one of the most widely diverse and abundantly distributed species on the planet, occurring on every continent except Antarctica. Most of them live in freshwater lakes, rivers, and ponds with the exception of a few saltwater species. They are easily recognizable by their barbels on the upper jaw and, sometimes, snout and chin, which look like the whiskers of a cat, giving them their name.

With over 500 different species of rays identified, this group of cartilaginous fish are more varied then their cousin the shark. Stingrays derive their name from their long, skinny tails, many of which have poisonous stingers used for self-defense. Due to these predominant stingers, please take caution when diving or walking through waters with stingrays. As long as you keep a safe distance, you can experience beautiful dives with them. They are mostly found on the seabed where they hide under the sand and feed on fish, crabs, worms, snails, and other mollusks.

One of the most fascinating fish on the reef, moray eels come in nearly every size and color from the tiny, bright blue ribbon eel, the smallest averaging only 25 cm long, to the black speckled giant moray which can grow up to 4 meters in length! In fact, there are nearly 200 different species. Most morays are marine dwelling fish, but several species have been seen in brackish water, and just a few are found in fresh water. They are clearly distinguishable from the other reef fish with their long, slithering bodies, pointy snouts full of sharp teeth, and long dorsal fins that run the entire length of their bodies. No matter the species, these animals are always an exciting site to see while scuba diving.

Not to be confused with the freshwater angelfish of the Amazon Basin, marine angelfish are brilliantly colored and live on the warm, shallow water reefs of the Atlantic, Indian, and western Pacific Oceans. This beautiful family of reef fish consists of about 86 different species, the most well-known being queen, king, french, royal, and grey angelfish. With their large, laterally compressed bodies, small, up-turned mouths, and bright colors, they are hard to miss and a favorite sighting for most divers.

There are nearly 130 different species of marine butterflyfish all living in the tropical waters of the Atlantic, Pacific, and Indian Oceans. These beautiful, small fish are known for swimming in monogamous pairs but can sometimes be seen in large schools. Like their larger cousin, the angelfish, they are a favorite sighting for scuba divers and snorkelers due to their beautiful, bright coloration and striking patterns. Another distinguishing characteristic is the eyespots many species have on their flanks to trick predators, similar to those found on butterfly’s wings.

Lionfish are native to Indo-Pacific waters and are usually found hiding under ledges or in shallow caves at depths between 2 and 60 meters. They are diurnal, meanings they hunt both during the day and at night but often stay hidden until sunset to avoid predators. Unfortunately, lionfish have become an invasive species in the western Atlantic Ocean and Mediterranean Sea. In fact, despite their menacing beauty, lionfish have become a huge problem in the Caribbean as their population has spread tremendously in just a single decade. In fact, the Science Channel has claimed they are “one of the most aggressively invasive species on the planet.” These flashy predators are considered fairly aggressive and harmful to humans so take caution when diving with lionfish and keep a safe distance.

An octopus has eight arms with suction cups which it uses as powerful tools for hunting prey, defense against attackers, and locomotion along the seafloor. They are one of the most fascinating marine animals on the planet. Every octopus has a designated “arm“ that it favors and uses most often. Because they have no inner skeleton, they are extremely mobile and can slip through the narrowest gaps and holes. Some species can even survive and move on land for a short time. Scuba diving with an octopus is an amazing and rewarding experience.

One of the most fascinating creatures of the sea, these small but mighty jelly-bodied, shell-less mollusks are part of the sea slug family. Nudibranchs inhabit ocean waters throughout the world, from the Southern Ocean to the Arctic, and everywhere in between. Depending on the species, adult sizes can range from 0.25 to 12 inches. These soft-bodied gastropods derive their name from the Latin word Nudibranchia, meaning naked gills, which is why most have feathery gills and horns on their backs.