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Marine Eel Care Sheet

Developed with and approved by a qualified veterinarian.

marine eel care sheet

This care sheet covers a variety of eels, including:

  • Snowflake eel
  • Green wolf eel
  • Jeweled moray eel
  • Yellow head moray eel
  • Palenose moray eel
  • Tessalta eel



Scientific name: Echidna nebulosa, Congrogadus subducens,  Muraena lentiginosa, Gymnothorax fimbriatus, Echidna nocturna, Gymnothorax favagineus

Because of the marine eel’s poor eyesight, they have developed an excellent sense of smell. Eels have an elongated, snakelike body and vary in size. Most eels possess striking body patterns and coloration. They open their jaws to allow water to flow over their gills for breathing. Eels have a pharyngeal jaw that they use to grasp prey and pull it into their throat. Eels are excellent escape artists, so a secure cover is recommended. One of the most popular marine eels for the home aquarium is the snowflake moray eel. Eels are recommended for experienced aquarists only.


Typical appearance and behavior

  • Marine eels are usually communal and sedentary
  • Eels tend to be nocturnal, spending the days hiding out in holes and caves
  • Marine eels have a reputation as vicious hunters but are usually harmless to people
  • Will eat small fish and invertebrates
  • Although called an eel, the wolf eel is a large species of dottyback



Care Difficulty Intermediate to advanced, depending on the species
Average Life Span Depends on species
Average Adult Size Up to 6+ feet long, depending on the species
Diet Carnivore
Minimum Habitat Size 50+ gallons, depending on species
Water Temperature 74.2-80°F, depending on the species, as some may prefer temperatures outside these parameters
Specific Gravity 1.020-1.025



Habitat size

Keep marine eels in an appropriately sized aquarium with a well-fitting hood as eels are known escape artists. A minimum of 50 gallons, depending on the adult size of the species, is recommended.


Building your habitat

Water health

  • Provide proper filtration to ensure optimal water quality to help maintain health. Moderate to strong water circulation should be provided to mimic water currents and high oxygen levels found in the eel’s natural habitat. Stable water quality (pH, ammonia, nitrate, nitrite) and water temperature are critical to the health of aquatic life. If you are unsure of your water quality, bring a sample to Petco for free testing. The addition of a protein skimmer can aid with maintaining great water quality and high dissolved oxygen levels. An aquatic heater should be used to stabilize water temperature, ensuring it does not fluctuate more than +/-2 degrees in a 24-hour period. The specific gravity should remain stable. Do not allow specific gravity to fluctuate more than +/-0.001 in a 24-hour period


  • Provide hiding places large enough for an eel to fit inside.



A well-balanced marine eel diet consists of:

  • Frozen silversides, krill, shrimp or other carnivorous frozen options, and freeze-dried krill
  • Squid can be given occasionally as a special meal


Things to remember when feeding your marine eel:

  • Feed one to two times a day, ideally in the evening or early morning before turning on the lights. Do not overfeed
  • Use caution when feeding; lower food with feeding tongs
  • Thaw frozen food before feeding


Marine eel care

Water care: Maintaining great water quality with regular water changes and adequate filtration is important to help keep your eel healthy

  • Daily: Check filter, water temperature and other equipment
  • Weekly: Test water quality at least once a week
  • Weekly to monthly: Change 10 to 25% of the total volume of water every two to four weeks or as needed; change filter media monthly

Avoid overcrowding, which is a major cause of stress and disease


Where to buy

Various eels are available for purchase at Petco online and in store; availability varies by location. If visiting your local Petco, please call ahead to check availability.




Aquarium mates

Compatible with certain species of:

  • Puffers
  • Triggers
  • Groupers
  • Large angelfish
  • Tangs
  • Large wrasse
  • Lionfish
  • Foxface/rabbitfish

Don't house with small, slow-swimming fish species and crustaceans

May become more aggressive in an overcrowded aquarium

They can be territorial; only one eel per aquarium is recommended



Signs of a healthy marine eel

  • Clear eyes
  • Healthy appetite
  • Bright, even coloring
  • Free of disease and parasites


Red flags (If you notice any of these signs, contact your local aquatic specialist or aquatic veterinarian.)

  • Loss of color or appetite
  • Spots or fungus on body or mouth
  • Erratic swimming
  • Labored breathing
  • Weight loss
  • Cloudy eyes


Common health issues

Health Issue Symptoms or Causes Suggested Action
Health IssueMarine ich or marine velvet Symptoms or CausesCysts on fins, gills and skin; rapid breathing; excess skin mucus or pale skin; fish rubs against hard objects or swims erratically. Suggested ActionQuarantine fish immediately and use a commercial parasite remedy; complete a water change, freshwater dips can help dislodge the parasites; consult your local aquatic specialist or aquatic veterinarian for treatment.
Health IssueBacterial infections Symptoms or CausesCloudy eyes, open sores and/or reddening of the skin. Suggested ActionImprove water quality; add freshwater aquarium salt; use a commercial antibacterial remedy as directed; consult your local aquatic specialist or aquatic veterinarian for treatment



  • How many types of marine eels are there? There are around 800 known eel species. Not all species with eel in their name belong to the order of Anguilliformes, including the green wolf eel.


Additional care sheets


Notes and resources

Ask a Pet Care Center associate about Petco's selection of products available for the care and happiness of your new pet. All products carry a 100% money-back guarantee.

Because all aquatic life are potential carriers of infectious diseases such as atypical mycobacterium and salmonella, always wash your hands before and after handling your aquatic life or habitat contents to help prevent the potential spread of disease.

Pregnant women, children under the age of 5, senior citizens and people with weakened immune systems should contact their physician before purchasing or caring for aquatic life and should consider not having aquatic life as a pet.

Go to the Centers for Disease Control at for more information about aquatic life and disease.


The information on this Care Sheet is not a substitute for veterinary care. If you need additional information, please contact your veterinarian as appropriate.