Moray Eel (muraenidae)

Contributed by TPERP Kirk Copic

Where to find them

Moray eels are some of the more elusive creatures lurking in our tide pools. They can grow to about 5 feet in length and are dark brown or green in color. They can live to be about 80 years old and spend most of their lives at a depth of 60 feet or less. There was one at the Birch Aquarium that was at least 80 when it died.

What’s Their Life Like

Adults tend to live in the deeper water while the juveniles live in the more shallow areas. Although moray eels are known to live at Cabrillo, they are difficult to spot in the lower tidal zone during the day as they prefer to hang out in crevices in the rocks with only their heads sticking out of their hiding spots. They are much more active at night since this is when they tend to eat. However, one way to look for them is to search for red rock shrimp. Moray eels are often found with these guys nearby as these specific shrimp help the eels by removing parasites and dead tissue.

Adaptations

Although moray eels are considered a type of fish, they don’t look quite so traditional. Instead of the normal side fins, moray eels have one long fin that extends from the top of the entire length of their bodies. This fin helps them swim through the water in a snake-like fashion. The gills on the moray eel are a bit different as well. Moray eels don’t have the normal side slit gills, but instead have small round gills. Most fish breathe by forcing water over their gills using gill covers. Moray eels don’t have these gill covers and instead breathe by taking water in through their mouth, forcing the flow of water over the gills. This behavior may make it look as though they are gasping for breath.

What Do They Eat

Moray eels eat mostly at night. Because of this, in order to find their prey, they must rely on their well developed sense of smell more than their eyes. They have three rows of razor sharp teeth that help with hunting their favorite treats of octopus, small fish, crabs, sea urchins and shrimp. While their teeth act as a great hunting tool, they don’t help much in the actual swallowing of their food.

Who Eats Them

While moray eels do not have many natural predators, they are hunted by barracudas and sea snakes. And, occasionally, moray eels will prey upon each other.

Reproduction

The reproductive cycle of the moray eel usually takes place in warmer water temperatures. Female moray eels deposit eggs on the ocean floor in well hidden places. They then release an odor that attracts the males to fertilize the eggs. It can take from 30 to 45 days for the young to emerge as larvae depending on the warmth of the water. It can then take up to a year for the larvae to drift as they grow and get strong enough to find an appropriate reef to call home. The water in Southern California is probably too cold for the eggs to hatch and it is believed that the eels here come from larvae that drifted north from Mexico.

Interesting Facts 

As such, moray eels have developed a second set of internal jaws that allow them to break up the food and push it back toward their stomachs. These razor sharp teeth are also used as a defensive weapon.

Classification
Phylum: Chordata
Class: Actinopterygii
Order: Anguilliformes
Family: Muraenidae
Common Name: moray eel
Scientific Name: Muraenidae

Source(s) of Information:

bio4esobil2009.wordpress.com

montereybayaquarium.org

oceanwildthings.com

sciencedaily.com

bioexpedition.com

a-z-animals.com/animals/moray-eel/

Last revised 24-Nov-17