Dolabella Sea Hare – Care, Diet, Are They Poisonous?

The Dolabella sea hare is a saltwater invertebrate. It can live in any size tank, likes temperatures between 72° and 78° Fahrenheit, and has a very peaceful temperament. Sea hares get along with all other types of fish and do well with any corals. The salinity in your tank must be kept steady, as well as the water hardness and the pH levels.

This article is about Dolabella sea hare care in a saltwater tank. You’ll learn what factors are important to control for the sea hare to thrive in the aquarium. Healthy sea hares play a role in keeping your tank clean, which helps the other fish stay healthy. Keep reading to find out what you can do to ensure the health of your Dolabella sea hare in your tank.

How Do You Take Care of a Sea Hare?

For starters, you must have a saltwater tank set to the right levels. Sea hares need the tank salinity to remain steady. Set the salinity to between 1.023 and 1.025 ppt. Make sure to keep that level tight. Fluctuation in the tank’s salinity can result in health issues for your sea hare.

The temperature in the tank is important also. Dolabella sea hares thrive in cool water. Keep the water temperature between 72 and 78 degrees. They also like to hang out in shady spots. Make sure to include some covered areas where sea hares can get away from the aquarium lights. 

Water hardness has to be controlled in a sea hare’s tank environment. It’s measured in degrees of carbonate hardness, or dKH. The dKH in your saltwater tank must be set between 8 and 12. Water hardness is also referred to as alkalinity. Add chemical solutions to your tank water to increase water hardness levels. 

Set the pH level between 8.1 and 8.4. Most saltwater fish require this alkaline level of pH. If the pH level in the tank drops lower than 7.0, the water will turn acidic. Then, you may lose many of your fish.

How Big Does a Sea Hare Get?

A Dolabella sea hare is a sea slug that can grow to a foot or more. Generally, they won’t get any bigger than 6 inches in a tank environment. Larger sea hares are found in the wild.

What size tank does a Dolabella sea hare need?

The Dolabella sea hare can live in any size saltwater tank. You can place them in the saltwater tank setup you already have. Even if your sea hare did grow larger than 6 inches, the tank you have would still accommodate it.

What Do Sea Hares Eat?

Sea hares are algae eaters. They eat a variety of algae. They eat hair algae, turf algae, red or green algae, and brown macroalgae. 

Interested parties often ask what they should feed their sea hares. The answer is nothing. Sea hares have a diet that consists only of algae. They will eat the algae inside the saltwater tank. 

The only times you would ever have to feed a sea hare is if you added them to a brand new tank setup or if your sea hares ate all the algae in the tank. In these cases, feed them dried algae or dried seaweed to tide them over. 

Is Sea Hare Ink Poisonous to Humans?

The Dolabella sea hare releases a purple ink substance if it’s startled. It’s a defense mechanism. It is safe for humans to touch. It will stain skin, though. 

While this ink is not toxic to humans, it can harm your small fish. When the ink is concentrated in one area, it acts as a toxin in small fish.

If, at any time, your sea hare inks in your saltwater tank, clean the ink out immediately. Ink is released when sea hares die also. Remove a dead sea hare as soon as possible to avoid harm to any of your other fish.

What Kills Sea Hares?

Dolabella sea hares are sensitive to copper, which can be present in water. Make sure your water doesn’t contain copper. That exposure will likely kill your sea hare. 

Sea hares have been known to get sucked into tank filters. Make sure to slug-proof your saltwater tank, so you don’t end up with a dead sea hare.

The only other issue you will encounter with sea hares is their clumsiness. Wandering around the tank, they often knock decorations, rocks, corals, and other items over. Some of this occurs when they dig into the sandy substrate laid at the bottom of your tank. Redecorating is a sea hare’s special talent.

How Long Does a Sea Hare Live For?

The lifespan of most wild sea slugs is right about one year. A Dolabella sea hare in a saltwater aquarium can live for up to six years. The key to keeping sea hares for longer is to maintain the reef tank environment properly. 

The other fish in the tank won’t bother the sea hare. Dolabella sea hares are calm and peaceful creatures. Their days are spent digging down into the substrate to get away from the light. Sea hares are nocturnal, so their nights are spent eating the hair algae in your tank.

Are Sea Hares Slow?

Sea hares are not fast movers. While they do move about in a tank, they do it at a sluggish pace. Most of their wandering will happen at night.

Remember, sea hares are nocturnal. If you don’t see your sea hare during the day, there’s no cause for concern. Most sea hares hide under plants, decorations, or sandy substrate until nighttime. 


Dolabella sea hare care isn’t difficult. Your sea hare will thrive at the right temperature, with the proper pH and dKH levels, and with a nice shady spot to hide. Sea hares don’t need to be fed because they eat the algae in your tank. Caring for your Dolabella sea hare gets you a clean reef tank in return. It’s a win-win situation.