Common Name: Zoanthid-Eating Nudibranch (Zoa Eating Nudi)
Scientific Name: aeolid nudibranchs (Main sub order)
Fan Fact – Nudibranch (pronounced Nudi-brank), means naked gills.
Aeolid Nudibranches are marine slugs and range in size from 2mm to 40cm. They are slug looking creatures with no shell and commonly have a leafy structure or thick tubes growing on their backs. Aeolids Nudibranches usually feed on sea anemones, corals, gorgonians, jellyfish and the most commonly observed kind in the saltwater aquarium hobby – Zoanthids. These ‘Zoa Eating Nudis’ are usually a couple of millimeters in size and can grow up to a centimeter depending of the species variety and age. They are commonly introduced with coral and live rock to the aquarium that was not quarantined and treated properly before introduction to the tank. Zoa Eating Nudibranchs like to stay hidden in the polyp mat and are sometimes hard to discover, closed polyps are a sign of irritation and can give away this little creatures position. This animal comes in a variety of colorations that include green-blue, red-white brown-white and many more, with the most common ones being a pale yellow and yellow-brown colorations. Aeolis Nudibranches are believed to need several individuals to establishing breeding populations that can lead to infestation, this means that physical removal of the animal with a pair of tweezers can be an effective treatment. Unfortunately, many zoanthid-eating nudibranchs are quite small and hard to detect before it is too late. If left unchecked to breed they can easily proliferate in the aquarium environment making eradication quite difficult.
Short video of the animal:
More Images of Zoa Eating Nudis:
Common Opinion: BAD
Prevention is the best medicine. A quarantine tank is the easiest way to prevent unwanted additions to the main aquarium. Ideally, Zoanthid corals should be left in quarantine for 3 months. During the quarantine time, you should dip the coral in a coral dipping solution such as CoralRx to try to remove any potential pests. This time period allows for monitoring of the coral health and watch for Nudibranchs or eggs and other pests.
As mentioned above, Aeolis Nudibranches are believed to need several individuals to establishing breeding populations that can lead to infestation, this means that physical removal of the animal with a pair of tweezers can be an effective treatment. This should not stop you from removing and isolating the infected coral if possible.
The biological approach, Introduce animals that are known to feed on Aeolid Nudibranches.
There are several fishes that were observed to eat these animals: Yellow Coris Wrasse (H. chrysus) and Kleins Butterflyfish (Chaetodon kleinii), unfortunately these fish may not be reef or coral friendly.
Salifert Flatworm Exit if known to be an effective treatment and is marketed as safe to both fishes and invertebrates and can be used in a reef tank. This product will not kill eggs, so the treatment will need to be repeated several times over a long period.
Focused precision treatment:
– Removing Affected coral and surrounding corals to a quarantine tank. With good lighting and waterflow.
– in a separate container that can house the entire coral use a dipping solution such as CoralRx. Use a turkey blaster and blast the coral with the dip for 5-10 minutes making sure it is getting in between the polyps and the underside of the coral.
– Remove the coral from the dipping solution and discard the solution you just used.
– DO NOT REUSE THE CORAL DIPPING SOLUTION as it may contain parasites and toxins released by the coral!
– Rinse coral with clean saltwater and return to the quarantine tank.
– Repeat this procedure for several times every 5-10 days letting the coral to recuperate in between. This procedure is to be repeated until no more nudibranchs are found.
– Leave the coral in your quarantine system for an additional 3 months before moving back to your aquarium.
Additionally, adding animals from the biological approach above to your quarantine tank will also aid in the treatment.