Next to sharks, eels have to be the most feared and misunderstood fish. Eels invoke thoughts of terror and wanton destruction. This may be because eels are similar to snakes, which also get little love and sympathy. Or perhaps this is another result of Hollywood's simplistic portrayal of this fascinating group of animals. In either case, the fear is unwarranted and one can successfully and safely keep eels in a home aquarium with a little planning and research.
While many people associate eels with saltwater aquariums, there are also freshwater eels, which means customers on both sides of the hobby can enjoy owning an eel.
Eels for saltwater aquarium come from three families Ophichthidae (worm and snake eels), Heterocongridae (garden and conger eels) and Muraenidae (moray eels).
Even though these eels come from different families, they share similarities. Some of these common traits are size, diet and behavior. Most eels are obtained when small but will quickly reach a size of 24 to 36 inches in an aquarium. They are all carnivores and need a variety of meat in their diet.
The majority want to hide in rock and caves, so the aquarium must be decorated accordingly. Last but not least, they are all excellent escape artists.
Together these basic traits mean that one should only put an eel in a large aquarium (50 gallons or more) that has a good filtration system because these fish need a lot more food than more common, smaller marine fish.
Their foods are also higher in protein than flake feed which means there will be more ammonia production, leading to nitrate buildup in the aquarium. Regular water changes are a must with these fish.
Water quality for saltwater eels is the same for all marine fish, as the ocean's basic water parameters, except temperature, are the same worldwide. These eels are all tropical and need a water temperature in the mid 70s.
Behavior differs among eels even in the same family. A popular eel is the zebra moray eel (Gymnomuraena zebra). The body of this eel is dark brown with white stripes running vertically down the body the entire length of the fish. They grow over 4 feet long, but are peaceful and will not bother tank mates. They are good for community marine aquariums but not reef compatible because they will knock corals over. This eels needs a large tank. It eats chopped fish, squid, mussels, clams and more.
Another popular moray eel is the snowflake eel (Echidna nebulosa). This eel also gets its popular name from the body coloration, which features white spots or splashes on a dark back-ground. The snowflake eel does not get as big as the zebra moray, but reaches about 2 feet in the aquarium, and it is easier to maintain. But it is a little more aggressive than the zebra, and it seems to spend its entire life trying to figure out how to escape from the aquarium.
This eel will eat fish and crustaceans smaller than itself, so the selection of potential tank mates is narrowed compare to the zebra. They need rocks and caves and may only come out at night.
There are smaller eels that can be kept in the aquarium and as a colony such as Hass' garden eel (Taenioconger hassi). These eels bury themselves in the sand, and if several are kept in the large tank, they will space their homes in the sand and all rise out of the holes looking like plant stems in the garden. These eels are difficult to keep, you should have the experience and patience needed to be successful with these species. Eels add a whole new dimension to an aquarium and are worth a try. With a little planning, you can be successful and enjoy these fish.
We hope that this guide was of help to you and your hobby.