I would like to take a moment to share with all of you one of my favorite fish in reef aquaria, and one that has consistently been a great addition to not only my tank, but to a lot of fellow hobbyists’ tanks as well. Pseudocheilinops ataenia, or as it is commonly known, the “Pink-Streaked Wrasse”, is a great little wrasse for tanks as small as 10 gallons (I personally would recommend 20 gallons or larger for reasons I will share later).
Note that a large amount of the following is based on my own personal experience with this little fish, but I have also done extensive research into others’ experiences with it. All pictures are of my own P. ataenia, who I have affectionally named “Lord Sauron” since his bright orange eyes remind me of the Eye of Sauron from the ever-popular Lord of the Rings fantasy novels by J. R. R. Tolkien.
P. ataenia comes from the Western Pacific Ocean, on tropical reefs located in and around the Philippines, Celebes (Indonesia), and Palau. It will normally be found in depths of 5 to 15 meters around grown out stony coral branches in small groups. It can be found often feeding on amphipods and other small invertebrates. It is not a fish that ventures far from its chosen area, often staying in and around coral branches so that it can make a quick getaway to shelter if needed.
P. ataenia is a very modest fish, and as such is not one to act aggressively towards any tank mates, oftentimes including other pink-streaked wrasses and small possum wrasses. Unfortunately, this also makes the pink-streak vulnerable to aggression from other fish since it would rather run away than try to defend itself. This is why it is best to keep P. ataenia in smaller tanks with peaceful tank mates.
Once established, P. ataenia will be very active in the aquarium. It can often be found closely examining rocks and corals for copepods, amphipods, and other small invertebrates that it considers a food source. For this reason, it may not be best to keep P. ataenia with dragonets or other fish that feed predominantly on copepods, amphipods, etc. P. ataenia will readily accept mysis, black or blood worms, cyclops, rotifers, and other frozen/prepared foods in the aquarium hobby as well as flake and pelleted food as long as the piece of food is small enough for it to eat. My own P. ataenia enjoys mysis and prepared food offerings such as LRS Reef Frenzy but has also taken to liking spirulina flakes that I sometimes offer my fish.
Personality-wise, P. ataenia is a very curious fish and will often stay around the front of the tank when you are around it, ever-watching you with those bright orange eyes as only a wrasse can. Unlike the more common and popular nano-aquarium wrasse, the Six-line Wrasse (Pseudocheilinus hexataeni), P. ataenia will not act aggressively towards newcomers. P. ataenia will most often casually swim around the aquarium, minding its own business and staying out of the way of tank mates. Some hobbyists have successfully kept pairs of P. ataenia, but as with other wrasses, P. ataenia can switch genders from female to male and possibly act aggressively towards other males.
P. ataenia can be successfully kept in tanks as small as 10 gallons, but it is also a very active fish and if there are going to be multiple fish in the aquarium, it may be better to keep P. ataenia in something like a 20 gallon reef aquarium. As with most wrasses, there is a risk of jumping and a tight-fitting lid should be kept on the aquarium at all times. It does sleep in a mucus cocoon, so a few small caves and crevices will give it plenty of options to hide in before it builds its cocoon.
P. ataenia may provide some pest control benefits as well. It has been said by other hobbyists that their P. ataenia consumed small bristleworms and feather dusters. I have personally seen my P. ataenia go after a vermetied snail. As with any fish, however, you shouldn't expect them to completely eradicate a pest, but merely help keep their population at a reduced level.
Overall, my experience with P. ataenia has been very positive. It is a great little inquisitive fish that fits well in my Innovative Marine Nuvo 20. It has been a much better experience than the year or so that I had a sixline wrasse, notably in the aggression field. Hopefully, these little guys will become more common in the hobby and more nano reef aquarium owners will share in my experience!