Instructions
Examine the length of the zebra moray eel.Captive older eels will reach a maximum length of 37 inches (57 inches in the wild), while younger ones will be much shorter and smaller in proportion (See References 1 and 2).
Look at the girth (width) of the eel. Younger eels are thinner than more mature ones. As a zebra moray matures, it becomes wider and thicker (See References 1 and 2).
Examine the stripes on the eel. Zebra moray eels are appropriately named and have white or black stripes that increase in number as the eel ages (See References 1 and 2).
Inspect the eyes and head of the eel. Younger eels have proportionately larger eyes and heads than older ones (See References 1 and 2).
Compare the eel you are looking at to other zebra moray eels. Ask the clerk at an aquarium shop if she knows the ages of the ones on display. Captive eels grow uniformly and if you can find out the age of a similar eel, you will have a good idea of your zebra moray's age range (See references 2 and 3).
Don't avoid purchasing larger, more mature eels. A zebra moray eel can live 20 years or more in an aquarium setting as long as its habitat is well suited to its size and behavior (See References 1 and 2).
How to Tell the Age of a Zebra Eel
There are over 200 species of eels but only 12 of those species are appropriate for a home aquarium. The zebra moray eel is well suited to aquarium living. With pebble shaped teeth that are designed to crush and grind prey, zebra morays eat mainly crustaceans; these eels tend to leave other fish alone as long as they are well fed. Knowing the age of an eel before you purchase it will give you an idea of how much you can expect it to grow. An eel's age is also an indicator of whether it is mature enough to reproduce (See References 2 and 3).