Updated August 6, 2019
Author: Mike - FishLore Admin
The Pencil Wrasse is found in the Indo-Pacific in lagoons and areas of high coral growth. Males are a blue green color and have two horizontal stripes of blue and yellow. Females or primary phase specimens are pink with yellow fins. One male can be kept with multiple females in the same tank but watch for aggression. They may not fair very well with other wrasse species either. It's hit or miss with these pencil wrasses when it comes to keeping them with clams. Some have great success while other hobbyists report that they have caught them nipping at their high dollar clams. Carpet surfer alert! They are excellent jumpers so a good fitting hood or canopy is needed.
Other than being a beautiful fish, these wrasses might (emphasis on might) also be able provide a great service to SPS reef tank keepers. Montipora corals have a very troublesome pest called commonly called the "Monti Eating Nudibranch" that can decimate a tank full of montipora capricornis in no time at all. It can be very difficult to keep these pests under control especially if you have large pieces that are difficult or impossible to remove from your reef tank. Several hobbyists over the years have claimed that these pencil wrasses will eat these monti eating nudibranches. Other hobbyists have tried them with less than stellar results when it comes to eating these nudibranches. It may be worth a try if your tank has these nudis but realize that you will always probably have these pests if you can't get them out to dip since there is not much evidence of any natural predators that eat the eggs of the nudis. If you frag your montis let the people you are sharing frags with know that you've had this problem so they can dip the frag before introducing it to their tank. Always quarantine all new corals and learn from your fellow hobbyists. An ounce of prevention is worth a pound of cure.
However, zoanthid keepers have had better luck with them when it comes to eating the zoanthid nudis which is also quite the annoying pest. Fireworms are also on the pencil wrasse menu.
Feeding them is the challenge, especially new arrivals. They do not ship very well and need a period of adjustment with lots of pampering. Offer them meaty foods such as mysis and brine shrimp 2 or 3 times per day. Aquarists with lots of long established live rock or established refugiums will have better chances of keeping them long term due to the amount of pods that they can pick at throughout the day. They also need a sand bed at least 2 inches deep so they can burrow when they feel threatened. Live rock with lots of hiding places works well too.
Overall, they are not really for the less experienced hobbyists. It goes without saying, but make sure your tank is fully cycled and that you have top notch water and a suitable tank (tank mates, inverts, etc) before you buy a pencil wrasse.
Pencil Wrasse Care
Scientific Name : Pseudojuloides cerasinus
Common Names : Smalltail Wrasse
Care Level : Difficult - can be difficult to feed or get a feeding response from newly acquired specimens
Life span : 7 years, likely longer
Size : Up to 5 inches (12 cm)
pH : 8.1 - 8.4
Temperature : 75°F - 79°F (24°C - 26°C)
Specific Gravity : 1.023 - 1.025
Origin / Habitat : Hawaii, Indo-Pacific - Found at depths of 2 to 60 meters (6 to 200 feet) in lagoons and areas of high coral concentrations. It has been divided into three different allopatric species in the Indian Ocean.
Temperament / Behavior : May attack shrimps, possibly snails and males my fight with other males of the same species. One male can be kept with multiple females.
Breeding : As of this time (2011) and to our knowledge this species has not been bred in aquariums.
Aquarium Size : 30 gallon minimum
Tank Mates : Should do well with other species but may fight with other wrasses. Use caution when keeping them with invertebrates such as shrimps, hermit crabs and clams. It's not widely documented that they will attack clams but, as always, be prepared to remove them if they are caught nipping your prized clams.
Reef Tank Compatible? : Could be considered with caution.
Disease : Saltwater Fish Disease - Diagnose, Symptoms and Treatment. These wrasses are not very good shippers. Ich (white spot - cryptocaryon) is common. High quality saltwater via Quarantine is needed upon introduction.
Diet / Foods : This is the hard part about keeping them. They can be very difficult to start eating anything you give them. Offer foods multiple times per day (2 to 3 small feedings at least) upon introduction. If they are eating after acclimation then 1 to 2 feedings per day of brine and mysis shrimp and/or the frozen meaty preparations for saltwater fish. I've tried pellets and flakes (and will continue to do so) but they just laugh at me.
Tank Region : Hides a lot and swims near the bottom or near cover.
Gender : Males are green with a blue tint and have two horizontal stripes with the top stripe blue and the bottom stripe yellow. Females or primary phase pencil wrasses are a pinkish orange with yellow fins.
Photo Credit : Photos copyright JJPhoto.dk
Michael, S. W. (2001). Marine Fishes, 500+ Essential to Know Aquarium Species. T.F.H. Publications.
More Wrasse Profiles
White Belly Wrasse
Sometimes mistakenly sold as the yellow coris wrasse, the white belly (Halichoeres leucoxanthus) is fairly hardy once acclimated but is still a prolific tank jumper. Many hobbyists have reported that they will eat montipora eating nudibranchs and acropora flat worms.
These tuskfish can be quite pricey and those coming out of Australia will usually fare better than those coming from the Phillipines. If you have a large saltwater aquarium with the right mix of tank mates this species can be a great addition or center piece to a display tank.