Dusky Wrasse Care Guide

Scientific NameHalichoeres marginatus
DifficultyMedium
Minimum Tank Size75 Gallons
DietCarnivore
Water Parameters72-78 F, pH 8-8.4, Salinity 1.020-1.025
AggressionPeaceful
Size7"

The Dusky Wrasse has one of the most dramatic color shifts possible in the home aquarium. Starting out as a dusky brown juvenile and transitioning into a vibrant peacock like fish, the Dusky Wrasse makes for a beautiful addition to any home aquarium.

They are easy to acclimate, accept prepared foods almost right away and can help hunt down pests that harm corals. They are most suited to tanks above 75 gallons with an established clean up crew.

Is the Dusky Wrasse Reef Safe?

The Dusky Wrasse is reef safe but will eat small inverts and worms of all kinds. This means they will do an excellent job protecting corals from pests but they will also hunt down any attractive worms you may have. Feather dusters and flat worms are common targets that aquarists do not want to lose.

The Dusky Wrasse uses the teeth on the bottom of its jaws to scrape food off of the rocks, meaning they can get some of the more stubborn pests, like large amphipods and pyramidellid snails. For tanks with expensive clams or corals that have issues with these parasitic snails the Dusky Wrasse is a great defender.

Aquarists will need to be careful when adding new coral frags to the tank. The Dusky Wrasse will likely pull on the base of the corals searching for food. If the new coral is not secured well it is likely to fall and become damaged or stressed.

Photo Credit to zsispeo on Flickr

Dusky Wrasse Tank Requirements

A sand bed of no less than one and a half inches is required for the Dusky Wrasse, as they enjoy burrowing for the night and when startled. This helps them preserve energy and reduces their stress levels as they feel much safer while they sleep in the sand bed.

When picking out a substrate for the Dusky Wrasse you need to find sand that is under 5mm in grain size. Gravel is never to be used with the Dusky Wrasse and neither is crushed coral. Rough substrate can tear at their fins and make them incredibly prone to diseases. Hard enough substrate will stop them from burrowing altogether.

Keep in mind that sand is much harder to add to an existing aquarium. If you plan on adding the Dusky Wrasse to a bare bottom tank you will need to read about adding sand to a tank with existing inhabitants. The short idea is that the sand must be wet and lowered into the tanks in clumps using tank safe containers to keep it from spreading around the tank while it is taken to the bottom of the tank.

A second note is that wrasse are frequent jumpers, especially when they are new to the aquarium. Seal up any holes in the lid to avoid an escape. The most commonly missed spots are around overflow boxes and filtration tubes.

Dusky Wrasse Diet

Wrasse of the family Halichoeres are easy to feed, accepting most types of food right away. This makes them easy to add to tanks without disrupting the diets of existing fish. In general the Dusky Wrasse should have a diet composed of:

  • Frozen mysis or brine shrimp
  • Chopped table shrimp
  • Seaweed|Nori
  • Prepared foods like pellets and flakes
  • Black and blood worms
  • Vitamin enriched feeder shrimp

The Dusky Wrasse will constantly be on the look out for any copepods, amphipods, worms of any kind(including feather dusters), small crustaceans and other various pests in the tank. These should not be considered a primary source, as even a large 300 gallon tank struggles to feed a much smaller dragonet. With the Dusky Wrasse being significantly bigger the food they find on the rocks and sand bed will act as little more than a snack.

Seaweed, which is often refereed to as nori, should be offered to the wrasse to help balance out their diet. If they do not accept the seaweed after several feeding attempts do not be too worried. Use a more plant based prepared food to help substitute the nutrients they would otherwise be getting from the seaweed. The more varied and balanced a fishes diet the better their colors will be. With the Dusky Wrasse being so vibrant we want to make sure their diet is the best it can be.

Occasionally there will be Dusky Wrasse who refuse to eat or stop eating. The main solutions for a wrasse who has stopped eating is to try more enticing foods. Going from prepared pellets to frozen mysis shrimp is often all it takes to get them eating again. More stubborn wrasse may need you to introduce live feeder shrimp. Many aquarists will use baby brine shrimp in this case. They are not too difficult to grow in a separate tank and can be fed whatever foods you want to pass on to your wrasse.

Dusky Wrasse Tank Mates

The Dusky Wrasse is fairly peaceful but they can be defensive around bed time when picking out a secluded burrowing spot. They are best kept with peaceful community fish or smaller semi aggressive fish that will not harass them.

When picking out tank mates for the Dusky Wrasse you should also be aware of territorial fish. Peaceful but territorial fish like clownfish will restrict the areas where the Dusky Wrasse feels safe. They will want multiple areas in the rock work where they can hunt for food and swim around in general. Likewise try not to keep too many bottom dwellers who might stop the wrasse from finding a burrowing spot.

Good Dusky Wrasse tank mates are:

  • Clownfish
  • Peaceful Wrasse
  • Tangs
  • Angelfish
  • Gobies
  • Basslets
  • Chromis
  • Butterflyfish
  • Surgeon fish

Other fish should not be dependent on copepods. The Dusky Wrasse will reduce the pod population of the tank to nearly extinct, making survival impossible for copepod eating fish in anything under 200 gallons. Exceptions would be tanks with effective refugiums to breed copepods or owners that target feed pod dependent fish.

Wrasse of the Halichoeres family will get along with one another as long as neither are unusually aggressive. There are exceptions as the family is giant, containing over 75 types of wrasse. Keeping multiple Dusky Wrasse is not too difficult, but may require a bigger tank to give them a bit of space from each other and reduce aggression.

Inverts are usually safe when the Dusky Wrasse is young and the inverts are of good size. When the wrasse gets older they are more likely to hunt shrimp and worms. Worms become unsafe much earlier in the Dusky Wrasse’s lifetime and should not be kept in the same tank if you are not willing to lose them. Feather dusters are the most common loss to Dusky Wrasse. Larger inverts should be fine even when the wrasse hits maturity.

Breeding & Gender

The Dusky Wrasse does not breed in the home aquarium. They can be seen spawning on rare occurrences when in a large tank and ideal conditions. To promote spawning the wrasse should be fed four small meals a day, have consistent light timing, water parameters and temperatures near the higher end of their preferred temps. Do not make the tank too hot and be mindful of heat created from the tanks equipment as many tanks do not have tools to cool the water.

Wrasse begin their lives as female and transition into male. When they change is dependent on their situation. The more dominant fish they are around the slower the transition will be. In the wild some will remain female their entire lives. In captivity the Dusky Wrasse will always become male.

The gender of the Dusky Wrasse is very easy to tell. Males will develop a vivid display of colors and stripes on their body with speckled green fins. Juviniles and females will be mostly brown with small green stripes on their head and a black spot on the middle of their dorsal fin. They will sometimes develop white lines going from their mouth to the mid point of their body. Males will lose the black spot during transition. It is the duller coloration that gives them their name of the Dusky Wrasse.

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