The Palenose Moray Eel (Echidna nocturna) is an uncommon species from the eastern Pacific. They only grow to about 28 inches in length, more commonly staying between 1-2 feet. They have olive green to dark brown bodies with pale spots. Their common names comes from the pale spots around the pores above and below the mouth and the orangeish colored nostrils.
Moray Eels commonly found in the aquarium trade are predators. They usually cannot be kept in groups and only one eel should be kept in most aquariums. Their natural diet includes smaller fish and invertebrates like crabs and shrimp; tankmates should be chosen carefully since an eel may prey on smaller tankmates. In the aquarium, eels can be fed a varied diet of fresh and frozen meaty foods like shrimp, crabs, scallops, fish flesh and similar items. It is not unusual for an eel to go on a "hunger strike" and not feed for several weeks at a time, especially after a stressful event like being moved to a new home. It is best to continue to attempt to feed the eel until it accepts the food; live feeders or appetite stimulants can be used to encourage feeding. Most eels, especially larger individuals, only need to be feed every two to three days.
Eels will usually establish a "home base" and spend much of their time peering out of the rockwork. Their mouth is often open, more as a way of "tasting" the water and environment around it rather than as a sign of aggressive since their eyesight is poor but sense of smell is keen. Most eels will not bother corals and stationary inverts although the large size of most and their housing in the rockwork can topple some colonies. Aggression can vary from passive, docile species to very aggressive predators and sizes can range from around a foot to up to six feet in some species often sold for home aquariums. Eels will get more aggressive around feeding time or when they smell food in the water.
While eels are not venomous, their mouths are full of bacteria and bites can get easily infected; avoid hand-feeding eels and be aware of the eel's location and behavior at all times. The teeth of most eels are curved and quickly pulling away once bit can cause the bite to be worsened; most eels bite out of defense and curiosity and will usually let go quickly. The tank should be covered tightly at all times since eels are prone to escaping from aquariums, especially if threatened. Weights or tank lid locks can be necessary for larger eels that might be able to knock the lid open. Morays are nocturnal and are most active at night.
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