Zebra moray eel

Zebra moray eel

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The zebra moray eel is a somewhat large fish living in the Pacific and Indian oceans. It is pretty easy to figure out how this animal got its name. The black and white stripes look almost exactly like a zebra’s. The black can sometimes be a chocolate brown instead. It is more of this color on the individual shown above. Most of the stripes are just vertical, but some of the white stripes have small branches off of them. Some of these eels have much thinner white stripes than the one shown above does. One special thing that all eels have is a flattened tail, it is hard to see that in the picture above though. The fact that it is flattened helps the eel swim better as a flat tail will push against the water more than a rounded tail would. Even though the zebra moray eel is a predatory fish, it is a rather docile animal. It rarely bothers fish even in an aquarium setting. Unlike most fish, eels do not have scales, their outer skin is more fleshy like a human’s. These fish are sometimes called just zebra eels.

Bite

I said that these eels are relatively peaceful, but they are not afraid to attack if they are agitated. Humans especially can irritate this eel due to how large we are compared to them. Their bite can be dangerous for two main reasons. First of all, they do not let go easily. After biting they will hold on, and even if they are killed after biting they will often continue to hold on. Secondly, zebra eels are thought to be venomous. Only thought to be though. They are actually not venomous, but their bite is still dangerous because there is a high amount of bacteria in their mouths. This can cause the wound to become infected if not treated well. There are several toxins that enter the bite victim, but they are not considered venoms as the eel does not make them specifically for protection or hunting. Also because it does not inject the toxins directly into the blood stream. Instead they are toxins that are found in the eel’s body and happen to be in the mouth where they then enter the wound.

Size

Zebra moray eels can grow to be rather large. Their maximum size is about five feet (1.5 m) although they are usually smaller, closer to three feet (.9 m). This smaller length is about the maximum they get in captivity. Even though they are so large, these fish are kept in captivity not only in aquariums but also as pets. They do need a large tank though. A pet zebra moray eel needs an aquarium of at least 150 gallons (568 l)!

Diet and hunting

These eels are typically very peaceful with other fish, but when they are hungry their attitude changes. Zebra moray eels will eat other fish when they are hungry, but fish are not their main food. Their normal diet is made of crustaceans such as crabs, lobsters, and shrimp. They will also eat other invertebrates such as sea snails, clams, squid, and sea urchins. Most of their hunting is done at night. At the Fort Wayne Children’s Zoo, these eels are fed fish, krill, and squid.

Moray eels, including the zebra moray, actually have two sets of teeth, and no, I am not talking about top and bottom. When a moray eel opens its mouth, a second jaw known as the pharyngeal jaw swings forward into their mouth. This is somewhat hard to picture in your mind, so below is an image showing what happens. Both sets of teeth are sharp, but the teeth on the pharyngeal jaw are pointed backwards so prey caught in that jaw cannot easily escape.

800px-Pharyngeal_jaws_of_moray_eels.svg

Zebra morays, along with other moray eels exhibit cooperative hunting with large fish called groupers. The groupers will signal a desire to do this by shaking their heads back and forth. The moray eels then catch fish which the groupers are unable to catch, usually fish hidden in crevices where only the eels can reach, and they share the meal. This is the only known cooperative hunting behavior between fish species. Often when hunting alone, moray eels in general will ambush their prey while hiding in crevices. Often they will go several weeks without eating.

I could not find a reason these eels share their food with the groupers. Why would any animal give up its food for no apparent return? I do have an idea though. Groupers are predators of moray eels, maybe wagging their head is a way of saying “I’m hungry, but if you catch me some food I wont eat you.”

Habitat and range

Zebra moray eels inhabit most of the coasts in the Indian and Pacific oceans. They live off the shores of Africa, New Zealand, Asia, Mexico, Hawaii, South America, and California. They are thought to not inhabit Australia, though. These eels spend most of their time towards the sea bed, but they don’t go in areas where that is very deep down. They typically stay higher than about 145 feet (44 m) below the surface. One of the things they especially like to have where they live is a lot of hiding places. This helps them protect themselves when they sleep. Reefs offer a lot of places to hide and are therefore common places to find these eels.

Status and threats

Although the IUCN has not classified the zebra moray eel, these fish are thought to be in stable condition. Other eels, barracudas, sea snakes, and groupers are some of the natural threats to these animals. Due to their ability to hid in small crevices and their nasty bite, these predators are not huge threats. Pollution, which can cause the reefs these eels live in to die, is probably the worst threat these animals must face.

Reproduction and young

These fish mate during the spring or summer. First individuals will open their mouths at each other to signal willingness to mate. The eels then twist their bodies around each other. This behavior can last for hours. As with most fish, zebra eels spawn to reproduce. Often one female will pair up with one male to spawn, but they will sometimes they will pair up with multiple smaller males. The eggs then float free into the ocean.

After hatching, the young zebra moray eels are shaped like tiny leaves. To give you an idea just how small they are, each female can release up to 20 million eggs at one time! For almost eight months these juveniles will float in the open ocean near the surface. At this time they are large enough to defend themselves, and they swim down to the reef to join the other creatures. It is not known how long these fish live in the wild, but they have been known to live up to 20 years in captivity.

Don’t forget to scroll down and comment your guess about what the next animal

mystery animal

Sources:

Photo credits:

  • Zebra moray eel – Public domain
  • Pharyngeal jaws – Zina Deretsky
  • Mystery animal – J J Harison

One Response

  1. Charis Dwire
    Charis Dwire at |

    Looks like a green tree frog to me.

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