Garden eels are separated into two different families, and while they have much in common with other eels, they are distinguished by the fact that they live in established colonies along flat, sandy stretches of seabed where not much else flourishes. Some live among beds of sea grass for extra camouflage; others are the only apparent concentration of life in a specific area. If you have never seen a colony of garden eels, try to visit a site where they thrive sometime; you’ll be fascinated.
Garden Eel Basics
Garden eels are found in the world’s tropical regions, throughout the Indo-Pacific and Red Seas, in the Caribbean, the Bahamas, and Florida. There are several different species in two genera, each with much in common. Typically ranging in size from eight to sixteen inches long, they dig burrows for themselves, in which they spend their entire lives.
No matter which type of garden eel you see, you’ll rarely see more than about a quarter of the eel’s body. That’s because these eels anchor themselves into their holes, which are kept intact via a cement that is formed from sand and the slime they secrete from their skins. When threatened by a predator or frightened by divers, they’ll disappear into their holes, leaving nothing but a flat, sandy surface behind. Sneak up on them though, and you’ll be treated to the sight of thousands of little eels, waving slightly in the current just like a bed of sea grass, which is actually what they are mimicking.
Usually found at depths between 5 and 60 meters, and sometimes preferring sandy slopes at the bases of coral reefs, these colonies form with the largest males in the center, and smaller animals along the periphery. In order to feed, they extend themselves from their burrows and point their faces into the current. With mouths wide open, they pluck bits of zooplankton and detritus from the water; each consumes several hundred bites of food during a typical feeding session.
To mate, the eels make new burrows, closer together. Males defend females they are interested in, biting at other males who try to move into the area; once mating has occurred, fertilized eggs float out into the current, where they hatch into larvae and grow. Once they’re a few inches long, the juvenile garden eels swim down into a suitable habitat and create new burrows.
Garden eels are not threatened, partly because they are prolific, and partly because they have only a few predators, including snake eels, which burrow beneath garden eel colonies and snatch them from below, and big triggerfish, which sometimes dive down from above to yank them from their burrows. Humans sometimes pose a threat, as garden eels are occasionally captured for the aquarium trade; but, due to the fact that keeping them in captivity is very difficult, and as they are adept at disappearing when threatened, they rarely fall prey to this fate. If you manage to photograph garden eels, consider yourself lucky; they are notoriously difficult subjects. Try hiding, yourself – your chances will improve significantly.