The Importance of Accurate Species Identification

Why Is It Important to Know the Latin Names of Marine Aquarium Animals?

Sally Lightfoot Crab
Tristan Brown/Getty Images  

It is not unusual to see saltwater fishes and invertebrates for sale in stores displayed only by common names, with no Latin, or what is known as scientific names posted. Why is this important? Because one of the biggest problems with identifying marine animals properly is that many similar or look-alike species are tagged with the same common name, which leads to their miss-identification. By doing this, you may be lumping an animal into a general category that does not pertain to that species particular environmental, dietary, or other aquarium care requirements.

Some Examples

Here is a good example. It was brought to our attention at one time by Robert Toonen that we had not accurately identified two Sally Lightfoot images linked under our Crab Photo Resources section. Rob told us that the true Sally Lightfoot Crab is the Grapsus grapsus, a species that is found in the cooler waters of the Galapagos Islands, whereas Percnon gibbesi, also commonly referred to as a Sally Lightfoot, and a Nimble Spray Crab, inhabits warmer tropical waters of the Caribbean.

Because the picture we linked to from Steve Gahaghan's Galapagos Islands Travel site of his Sally Lightfoot Crab picture does not include the Latin name with it, we assumed that the Latin name shown with another site's photo we had linked to previously made them one and the same species. Wrong! When we compared these two species of crabs side by side, the differences in their appearance, coloration, and markings were clearly defined, which you can see for yourself by viewing these pictures:​

Galapagos Grapsus grapsus Species:

Caribbean Percnon gibbesi Species:

Accurate species identification is of the utmost importance to the survival of marine fishes and invertebrates in our care. From this Sally Lightfoot example, you can see that the two crabs are similar, but definitely different. One crab requires a colder water habitat, and the other a warmer one, which can be bad news for either one if they are put into the wrong environment.

Next >> Problem Marine Animal ID Communications from Robert Toonen

Robert Toonen has an extensive education in the field of Marine Sciences, with a Masters Degree in Marine Biology and a Ph.D. in Population Biology. You are probably familiar with his name from the many articles and publications he has written, particularly his Reefkeeper's Guide to Invertebrate Zoology series for Cybermagazine over the years. Another popular resource from Rob is his Polychaete (aka "bristleworm") FAQ For Reefkeepers information.

Sally Lighfoot Crab Photo Misidentification Mishap

In his communications to us regarding our Sally Lighfoot Crab photo misidentification mishap, Robert expressed that, "I have personally seen tanks with at least three different species in them at one local pet shop with a bright sign declaring, Sally Lightfoot Crabs -- Reef Safe! I think that when a common name like "Sally Lightfoot" or "Tigertail" catches on, suppliers occasionally ship anything similar for which there is no real common name under the more recognizable nickname like these. I think it is important to get people to at least mention Latin names when talking about animals with common names like these. I'm sure that everyone realizes that there is plenty of individual variation in animals, but I suspect a lot of the conflicting information about how a given animal performs in aquaria may largely reflect the fact that people in different places are sold different animals under the same common name."

Robert further commented that, "I can't remember how many times I've pointed out that "red sponge" is about as descriptive as "red fish" -- there are too many species to draw any inferences from a non-specific description like this. No one would consider asking questions like "how do I keep a red fish?", but such questions are common when dealing with inverts. It's even more important to be specific with inverts because the range of differences in life history, feeding mode, and habitat requirements among many groups such as sponges are much greater than the range for all species of fish."

We are in total agreement with Rob on all of these points, and here is another prime example that brings them home.

Next >> Triggers! Another Prime Example of Mis-Common Name Use Problems
Previous << Why Is It Important to Know the Latin Names of Marine Aquarium Animals?

Let's talk Triggers! From our experiences, Triggerfishes are another prime example of mis-common name use problems when it comes to identifying them accurately. It is not unusual for any Trigger to be referred to as a Humu Humu, and when asked by a saltwater hobbyist for help in caring for their Triggerfish, we get questions like this all too often:

  • I have a Humu Humu. Can you tell me how big it will get?
  • Will two Humu Humus get along in the same tank?

Ok, well, yes you have a Humu Humu, but which species? Give us the Latin or scientific name, and we can tell you how big it will get if it is one of the more aggressive or non-aggressive types, what it prefers to eat the most, and so on. Triggers worldwide may be similar in appearance, but not every one of them has the exact same characteristic traits.

Test Your Knowledge

Here's a test. Can you identify these two species of Triggerfishes, Rhineacanthus rectangulus, and Rhineacanthus aculeatus. Both are referred to as Humu Humus, AND as Picasso Triggers, but only one of them is the true Picasso, and the other just tagged with the same common name.

When it comes to accurately identifying marine fishes and invertebrates, don't be fooled by a common name. Accepting a general or common name an animal is labeled with is not wise. What one specific species requires for care may not necessarily pertain to the other.

It's easy to learn, or at least look up the Latin names of marine aquarium animals. All you need are a few good profiles and care reference guides in your library.

~ Debbie & Stan Hauter

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