Melanurus Wrasse

Why is the Melanurus Wrasse one of our favorite reef tank fish?

by Justin Hester

When it comes to reef aquaria, there are hundreds if not thousands of fish to choose from. Most either fall into the category of “looking cool” or “doing something beneficial” in your reef aquarium. The melanurus wrasse in my opinion is one of the best in both categories. It can be one of your best friends as far as actively seeking out coral pests and its totally fun to watch it do so as it darts and pokes its way through every piece of rock work.  We think if you are looking to add an interesting fish that definitely has a purpose to your reef aquarium, you don’t have to look further than the melanurus wrasse.

Melanurus wrasse biology

Halichoeres melanurus (Bleeker, 1851) or “Hoven’s Wrasse”  as its sometimes, called belongs to our favorite genus of wrasses called the halichoeres.  These wrasse I commonly refer to as the pickers as their mouth seems to be designed just perfectly for picking things like pods and pests from corals and rock work.  They go by a few names in the hobby including Orange-tipped, Rainbowfish, Tailspot, and Neon Wrasse.  They grow to approximately 5″ and are peaceful towards each other and all tank mates, but given their need for hunting territory, we only reccomend 1 per tank.  There are approximately 43 species that make up the halichoeres genus and we have had many of them over the years safely in our reef tanks despite their common listing as being reef safe “with caution”.  Personally, I think this relates to the face that as they become larger mature adults, some of our shrimp may become a part of their food source.  Personally, I have never had this issue and have had some individual for many years.

Like many wrasse and fish in general, the Melanurus goes through a juvenile to adult ( terminal phase)  color morph.  Unlike many fish that have bizarre and unusual colors as juvenilles, only to become dull or muted when they cross to adulthood, the Melanurus actually has more of a bright coloration as an adult. When you buy these wrasse as juvenilles they are often mislabeled as a “twin spot” or some other wrasse as they look very different from their adult phase, sporting long red stripes and a black dot on their dorsal and tail fins. When their cross to adulthood, these red stripes change to alternating turquoise blue and red lines with a distinctive red background near their head and neck.  You can see these side by side here on the picture from Live Aquaria.

Melanurus Wrasse

Care and Feeding

About the only thing you really need to be concerned with in keeping these awesome fish is keeping a tight lid on your aquarium.  They are notorious jumpers and I’ve seen them in our coral grow out tanks actually swim along the top of the water with their head out of the water as if looking for a place to jump to.  Needless to say, this usually ends up in a short live carpet fish so please make sure you have high walls on your tank or a screen top before trying to keep one.  You can get a screen top we like one like this:

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Feeding these wrasses as discussed is easy as they will usually get used to whatever you are feeding your other tankmates such as mysis and even flake food.  If you want to give them and most other wrasse or butterfly fish in your tank, you can crack and toss an occasional clam into the tank for them to tear apart.  Just make sure you scrub the clam and rinse it once you crack it to keep any unwanted things from your tank.

Melanurus Pest Control

As we briefly mentioned above, the melanurus can be your best friend in the world of pest control.  They make a great natural ecosystem approach to controlling many of the pests that we see in the reef aquarium hobby.  In fact, I have personally witnessed many of the wrasse in the halichoeres genus to be excellent at pest control.  This is one of the reason’s that we have a handful of them in our QT system for all the new corals we are growing out.  If you know you have pests such as monti nudi’s and even AEFW, we have witnessed them eating both actively.  The below is a video we took of some of the Melanurus’ halichoeres cousins at a local pet shop that we tossed a few monti nudi infested frags into.  Look at them attack!

One important note about using wrasse or ANY other natural means to control predators.  Using this “ecosystem” approach to pest control where you basically complete one segment of the food chain by adding a predator where another population has grown out of control has its limitations.  Keep in mind that this method will keep pest populations in check so your corals aren’t consumed overnight, but at the same time eradicating the pest population altogether should not be the expected outcome.  Life will typically find a way for monti nudi’s or AEFW to survive in some nook or crevice of your corals where the wrasse can’t get to them.  That being said as soon as their populations grows beyond that nook, boom, the wrasse will get them!

The Melanurus wrasse is tops in our opinion for anyone wanting a very colorful fish that also serves an important role in your reef tank.  They will give you hours of enjoyment and can be a natural alternative to pest control.  If you decide to add one to your tank, just make sure you secure your tank so they don’t jump out!

Here are a couple of products to help you take care of Melanurus Wrasse mentioned:

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