Are you looking for a great saltwater fish to add to your saltwater tank? Ask your local fish store to order you a male Melanurus wrasse—quite possibly the best-kept secret in the saltwater aquarium hobby. And if you’re in any doubt, there are seven top reasons as to why you’ll want to make this stunner your next aquarium addition.
Table of Contents: Melanurus Wrasse
The Melanurus wrasse comes with plenty of positives. And if you have a particular idea in mind for your reef tank, you can jump down to the link that catches your eye. But if you want to get the full effect of these gems, stick around through the entire article (you’ll get the most appreciation that way—and they’ll win you over in no time!).
Common Names
If you start hunting around for your new wrasse addition, you might find yourself confronted with different names. The Melanurus wrasse also shows up as Hoeven’s wrasse, tail-spot wrasse, yellow-lined wrasse, orange-tipped rainbowfish, and pinstripe wrasse. The names all attempt to capture the image of a single species: Halichoeres melanurus. However, you may see an incorrect label of Christmas wrasse, pink face wrasse, or ornate wrasse. These other fish have somewhat similar appearances. So make sure you check with the fish store as to the species you’re bringing home.
Top 7 Reasons to Keep Melanurus Wrasses
If you have aspirations of beauty, activity, or ease of care, you probably have a shortlist of your favorite saltwater fish species. And if you haven’t considered the Melanurus wrasse, it may be due to a lack of information. That’s where this handy reference list will clue you in. Every good facet (and a few warnings) will pop out for you to peruse. And then you can decide if this delightful fish makes sense for you.
Appearance: The Stunning Melanurus Wrasse
Once you see your first Melanurus wrasse, you’ll fall head over heels in love. Don’t take my word for it, though. Look at these pictures (even THEY don’t do this fish justice!). The adult male Melanurus wrasse starts with a typical wrasse shape and covers it in an amazing blend of turquoise blue and green colors. Then you get red, horizontal maze-like stripes from head to tail. It’s similar in the palette of the six and four line wrasse species, with enough pop to make them stand out in any reef background.
Unlike some angelfish species, which start as brightly-colored juveniles and turn into drab-colored adults, Melanurus wrasses grow into their color. So if you start with a youngster, you can expect those colors to gain in intensity as your fish matures.
Adult males are considered more beautiful than females. And if you decide to keep a single wrasse, with NO other aggressive fish in the tank, you’ll luck out in the deal. This species is a sequential hermaphrodite. That means they change sex depending on the social situation in the group. So all Melanurus wrasses begin life as females. And while maintaining those lovely shades, they’re a little on the dull side. But without any other males around (or if they manage to become the dominant fish in a territory), the fish will change sex to male and adopt the brighter color patterns.
Hardiness
Aquarists love the Melanurus wrasse as it comes with a hardy reputation. They’re almost impossible to breed in captivity (the fry don’t usually survive), but it’s easy to collect them from the wild. And as long as you have your new striped beauty go through the usual quarantine process, you shouldn’t deal with much in the way of infection or parasites.
Part of this comes from the habit Melanurus wrasses have of burying themselves in the sand. Fish that dive into the sand—whether they’re sleeping or hiding—scrape their scales between the grains. This behavior acts as a natural “barrier” against the most common external parasites that like to attach to saltwater species, providing mechanical removal and stress reduction. However, this does not make the fish immune to all diseases. Internal parasites, bacterial infections, and other pathogens can still affect them, so sand-burrowing is only one line of defense.
It’s important to note that the effectiveness of sand-burrowing as a defense depends on your tank setup. If the sand bed is too shallow (less than 1 inch), too coarse, or absent, the wrasse cannot burrow properly. This can lead to stress, increased disease risk, and even physical injury from attempting to burrow into an unsuitable substrate. Always provide at least 1 inch of fine sand to support this natural behavior.
While Melanurus wrasses are generally hardy, their wild-caught status means they can be more prone to shipping and acclimation stress than captive-bred fish. Stress during transport and acclimation can make them vulnerable to disease outbreaks or failure to thrive. To mitigate this, use a slow drip acclimation process, keep lighting dim during introduction, and ensure a sand bed is available from the start. Even though they are considered robust, a thorough quarantine protocol is essential. Wild-caught fish may harbor latent diseases that can be introduced to your display tank if not properly quarantined and observed for several weeks.
And while the Melanurus wrasse usually comes into a fish store via wild collection, they don’t adopt hunger strikes or other dramatic behaviors the way more delicate species might. The worst you may encounter? Once your Melanurus gets established in a tank, it can get impossible to remove them again. Aquarists often have to haul EVERYTHING out of an aquarium to find and catch their sneaky fish.
The Diet of the Melanurus Wrasse
One of the reasons the Melanurus wrasse does so well in an established reef aquarium is its voracious appetite. They’re active fish that swim non-stop throughout the tank. This high activity level, combined with a short digestive tract, means they process small amounts of food rapidly and require frequent, small feedings to maintain health and coloration. If their metabolic needs aren’t met, they may become emaciated, lose color, or turn to hunting invertebrates in your tank.
Of course, you want to make sure you balance their diet properly. Otherwise, you won’t keep those brilliant stripes looking their best. As such, you want to mix things up for these carnivores with some live or frozen proteins:
- Brine shrimp
- Mysis shrimp
- Seaweed or nori (Yes, even carnivores need a little plant life in their diets)
And to keep that digestive tract running properly, you’ll need to offer food FOUR TIMES A DAY. That’s higher than most of the fish in your aquarium. An active Melanurus wrasse can start causing problems if they don’t receive a proper amount of food, such as increased aggression, predation on invertebrates, or visible signs of stress like color loss, lethargy, or fin erosion. On the other hand, overfeeding can lead to water pollution, algae blooms, and obesity.
Practical strategies for managing frequent feedings include using auto-feeders for dry foods, preparing frozen food in advance for easy portioning, and coordinating feeding times with the needs of other tank inhabitants. Monitor your wrasse for signs of nutritional deficiency or stress, such as faded coloration, listlessness, or ragged fins, and adjust your feeding regimen as needed. (If your wrasse doesn’t want to eat the seaweed, you can leave it out. They may graze on algae within the tank.)
Do Melanurus Wrasses Eat Cleaner Shrimp?
As omnivores, the Melanurus wrasse doesn’t mind sampling from the meaty side of the menu. And when they get hungry? They’ll happily consume feather dusters, crabs, shrimp, and snails. This means they’ll potentially turn on your clean-up crew, given a chance. Coral banded shrimp run the risk of consumption if you have a large male Melanurus wrasse, topping out at that 6-inch (15.2cm) length.
The risk of predation on shrimp depends on several factors: the size and hunger level of your wrasse, tank size, the availability of hiding places, and the species and size of the shrimp. Larger, well-fed wrasses in smaller tanks with limited rockwork are more likely to hunt shrimp. Behavioral cues that predation risk is rising include the wrasse stalking shrimp, shrimp hiding more than usual, or unexplained disappearances of invertebrates.
To reduce risk, ensure your wrasse is well-fed with frequent meals, provide ample rockwork and crevices for shrimp to hide, and consider introducing shrimp before the wrasse so they can establish territories. Choosing larger or more robust shrimp species can also help, but the risk is never zero—individual wrasses vary in their behavior. Always monitor interactions closely, especially in the first weeks after introduction.
However, many reports online of aquarium owners say the Melanurus wrasse will not eat cleaner shrimp. (Odds are they’re keeping up with the four daily feedings, though.)
Will Melanurus Wrasses Eat Nudibranchs?
Now you’re probably wondering about some of the other invertebrates in your tank. For instance, what if you have nudibranchs? And, as you might guess, a hungry Melanurus wrasse will eat the nudibranchs feeding on Montipora. They also target flatworms and parasitic pyramid snails. THAT probably sounds like music to your ears, but you shouldn’t rush out to get a Melanurus wrasse as a pest control method.
Effectiveness as pest control is inconsistent. Individual wrasses have variable feeding preferences, and some pest nudibranchs may be unpalatable due to chemical defenses, size, or nocturnal habits. More than likely, you’ll find your Melanurus feeding on the nudibranchs you paid for and WANTED within the aquarium. Use Melanurus wrasses as part of an integrated pest management approach, not as a sole solution, and monitor for unintended predation on desirable invertebrates.
Growth
What’s one of the worst things about starting a new saltwater aquarium? Waiting for those small, young fish you purchased to grow to their impressive adult sizes. Juvenile Melanurus wrasses often come home from the fish store in the 1.5-2-inch (3.8-5cm) range. But they quickly grow to their full 5-inch (12.7cm) adult size. It only takes about 3 years for that little striped squirt to turn into the impressive fish you admired in all of these pictures. Compared to many slower-growing species out there, that’s a record!
This rapid growth means you should plan for their adult size from the start—choose a tank that can comfortably house a 5-inch, highly active fish. As your wrasse matures, its feeding needs and social behavior may change. Increased size can lead to greater territoriality or aggression, especially if tank space is limited or if there are other wrasses present. Monitor for changes in behavior as your fish grows, and be prepared to adjust tankmates or aquascaping if needed.
Melanurus Wrasses: Active Charmers
The Melanurus wrasse comes packed with personality—enough to match those vibrant colors. During the daytime hours, you’ll see the fish zipping in and out of the rockwork, hungrily looking for something to eat. And since they don’t typically hassle corals, you’re in the clear to stock them in your reef tank. It’s only when they get hungry that you may want to worry. A starving Melanurus wrasse may start to decimate the planktonic food supply your corals need to fill that short GI tract.
But the charming behavior doesn’t end when the sun goes down! When a Melanurus wrasse is ready for bed (or if it gets scared), it burrows into the sand for the night. The sand protects the fish from nocturnal predators that scour a reef during the overnight hours. (And, of course, it keeps those parasites away and gives the wrasse its hardy nature.) Once the morning comes around, they wake up and shake off the sand to start their swimming routine again.
Oh, by the way, since this wrasse buries itself in the sand, make sure to pick a fine grain sandy substrate at least 1 inch deep to support this essential behavior.
Is the Melanurus Wrasse Aggressive?
Wrasses, in general, have an aggressive reputation. And the fact that the Melanurus wrasse will snatch up a cleaner shrimp without a second thought probably has you thinking the fish will pose problems in the tank. And since they swim almost constantly, that CAN irritate some fish within a tank, leading to chasing behaviors. But the Melanurus wrasse is actually shy, coming in on the peaceful side of the scale.
The main drivers of aggression in Melanurus wrasses are territory, food competition, similar appearance, and tank size. If you want to maintain calm within your aquarium, pair them up with fish of similar size and temperament that do not share the same feeding niche. Avoid housing them with species like dragonets, as the wrasse will quickly outcompete them for copepods, leading to starvation of the less aggressive feeder.
Diagnostic cues for aggression include chasing, hiding, and torn fins. If you observe these signs, practical interventions include rearranging rockwork to break up territories, increasing feeding frequency, or, if necessary, removing aggressors. Aggression may increase as fish mature, so always have a backup plan in case previously peaceful tankmates become incompatible.
You CAN keep the Melanurus wrasse with other wrasse species—provided there’s space. That even includes two males. You need room to diffuse potential tension. And you should still monitor interactions over time. As any fish ages, it tends to lose tolerance and get grumpier. That means two Melanurus wrasses that got along fine in their younger years can start to grow aggressive down the road. Always have a backup plan—just in case.
The Melanurus Wrasse: A Cleaner Fish?
Okay, so the Melanurus wrasse is ranking up checkboxes in the form categories. But how about one more in the functional category? This wrasse is a helpful fish to add to your tank courtesy of the tendency to eat parasitic pyramid snails, flatworms, bristleworms, and nudibranchs. (Well, except for the nudibranchs you DON’T want to be eaten.) On their constant patrols of the aquarium, they’ll hunt down all of these common pests for food. It makes them a handy part of your tank’s clean-up crew.
But you don’t want to rely on them 100%. Individual fish may not always have a taste for particular parasites. You could end up with a Melanurus wrasse that doesn’t care for bristleworms, for instance. And then you’re going to have to cope with the problem on your own.
Reef-Safe
Officially, the Melanurus wrasse comes in as MOSTLY reef-safe. I know, that’s a troubling description. Aquarists prefer fish to fall into handy categories of “reef-safe” or “not reef-safe.” Overall, you’re in the clear. The “mostly” label comes from their habit of snatching up invertebrates. They like to eat shrimp, feather dusters, and crabs. And if you don’t supply them with a proper diet, that habit will go into overdrive. But as to corals? They’re in the clear. In fact, plenty of hobbyists say their Melanurus wrasses were great additions.
Of course, one aquarist mentioned his wrasse developed a habit of flipping over snails and nipping at them (without killing them). So roll the dice and watch your wrasse carefully when you add it to your reef tank.
Cautions with the Melanurus Wrasse
Watch out, the Melanurus wrasse jumps. (No, seriously!)
Unfortunately, like many wrasse species, Melanurus wrasses surf on carpets. This is because aquariums don’t provide the same depth the fish get used to in the wild. When they cruise a reef and flee from a predator over a reef, they have more than a foot of water over their heads. But in a tank? That isn’t the case. As such, they often sprint up and end up bolting out of the water.
Jumping is triggered by several biological and behavioral factors: sudden startle responses, territorial disputes, chasing, or even searching for food. To prevent escapes, keep a tight lid on your tank or install a mesh cover. Effective tank covers should have a snug fit, small mesh size (to prevent even small wrasses from escaping), be made of durable material, and allow for easy maintenance access. I’ve lost a few fish that way over the years (a real bummer).
Also, since they ARE aggressive eaters, it’s best to limit yourself to ONE per tank. The Melanurus wrasse will use the entire tank as a feeding ground, picking it clean of tiny, mobile invertebrates (like copepods, amphipods, etc.). While they’ll tolerate sharing space with each other, you may not be able to provide enough “ready” food for everyone. And that WILL lead to aggression problems.
And while they’re not the largest fish out there, it’s generally not recommended to keep this fish in anything less than 40-50 gallon (141-189L) tanks. Remember, they’re active fish, and they need plenty of territory to cover throughout the day. You also need AT LEAST one inch of fine sand bed on the bottom for them to burrow into. Anything less, or using coarse substrate, and they’ll end up stressed, unable to burrow, and at higher risk for injury or disease due to the loss of this natural behavior.
For More Information
STILL not convinced you need to add a Melanurus wrasse to your tank? Well, this YouTube video ought to do the trick:
If you’re looking for other awesome saltwater fish for your aquarium, how about these perfect tank mates for the Melanurus wrasse (hint, hint):
Conclusion
I’ve been in this hobby for a long time now, and I was slow to notice the Melanurus wrasse. I knew about the stunning beauty of other wrasses, though: fairy wrasses, flasher wrasses (carpenter, McCosker’s), you name it. I was also aware of the somewhat similarly colored and notoriously troublesome six line wrasse and the ubiquitous but challenging to feed bluestreak cleaner wrasses.
But somehow, the Melanurus wrasse remained a secret. Not any longer, though! And I hope you get as much enjoyment out of checking out this fish as I do.
Leave a comment and share whether you’re interested in this fish or if you’ve already had success keeping it.
I love my Melanuras Wrasse! Very entertaining and they do a great job at keeping the bristleworms to a minimum!
Thanks for sharing, Sandee! How long have you had yours? Glad to hear it is a great fish!