Fish in the Galápagos

By Christopher Minster

Galapagos is world-renowned as one of the best places in the world for diving and snorkeling. If you choose to dive, snorkel, or take a tour in a glass-bottom boat, chances are very good that you will see a number of beautiful, exotic fish and marine animals.

The most common member of the Angelfish family is the colorful, disc-shaped King Angelfish (Holocanthus passer). It is easily identified by its bright yellow tail and white stripe extending the length of its dark body just behind the pectoral fins.

The Flag Cabrilla is a olive/greyish fish commonly seen in most snorkel and dive sites.

Damselfish are also very abundant throughout the archipelago. Although all damselfish can be distinguished by their elongated, elegantly flowing dorsal and tail fins, different species in the damselfish family have their own distinguishing characteristics.

The Great Damselfish has a gray body that fades to black near the tail, with breeding males demonstrating a striking silvery-white face. The Yellow-tailed Damselfish (Stegastes arcifrons) has a bright yellow tail (obviously) and lips, blue eyes, and purple-black body. The white-tail damselfish has a distinctive white stripe at the base of it's tail and orange "eyebrows" that make it easy to identify. The Sergeant Major (Abudefduf troschelii), a common reef fish throughout the tropics with black and yellow stripes and disc-shaped body, is also a member of this family, commonly spotted at major snorkel sites. Even though all damselfish are attractive (such is the fate of “damsels”), the juveniles are often the most visually pleasing, because they have iridescent blue spots that shimmer as they swim in the water.

Damselfish are usually found solitary or in small groups of up to three. Even though they are often found in the proximity of other fish, they are extremely territorial and will often chase away intruders (even humans) encroaching upon their algae patch.

If you're attentive while snorkeling or diving, you may notice something strange about that oddly-shaped rock on the bottom. Look more closely: you may have spotted a stone scorpionfish. By all means, take a closer look: just don't step on it, as the stone scorpionfish has quite the defense mechanism -- venomous spines along it's back!

Parrotfish are one of the easiest fish to identify in the Galápagos, because they are large, colorful, scaly, and shallow swimmers. Colors vary depending on species and age, but most parrotfish are orange with silver scales, red and black, or most often blue-green with colorful specks. One species, the Bumphead Parrotfish, has a very distinctive noggin: as the name implies, it has a flat, bulbous forehead.

Besides their bright coloration, all parrotfish have a beak-shaped mouth (hence the family name), which can serve to bite off and grind up large chunks of coral. They are very important for nutrient cycling.

Surgeonfish are another guaranteed sighting during a snorkel session in the Galapagos. All surgeonfish are flat and oval-shaped and swim in massive schools. They also have sharp retractable spines at the base of the tail, which can be used to make precise incisions (like a surgeon’s scalpel) in their predators. The most abundant species is the Yellow-tailed Surgeonfish, which, besides possessing a yellow tail, has three distinctive horizontal black polka-dots preceding the tail. It is found in just about every snorkel site in the archipelago.