Purple Dottyback Care Guide

Scientific NamePseudochromis porphyreus
Final Tank Size30 Gallons
Water Parameters72-78 F, pH 8-8.4, Salinity 1.020-1.025
The Purple Dottybackis a beautiful fish that most aquarists will skip right over. They are small bullies that are persistent in harassing anyone too weak to stand up to them. Adding them to a tank that was not built with them in mind is a quick way to have the existing fish wiped out as the Purple Dottyback becomes established therefore more aggressive. Only try to keep them, a single dotty back, if you are 80% sure they will not harm any of the fish in your aquarium. Even in larger aquariums these little fish can be a big problem.

In the wild we can frequently see the Purple Dottyback swimming in decent sized schools around coral reefs and large rock structures. They will typically stay around a few selected homes, hiding inside caves and coming out to feed. This makes them highly suited to aquarium living as that is exactly what they do in our homes. They are quite hardy and will survive the trip to most aquariums when provided proper care and a good starting diet of live foods. Once they become established they are very easy to care. They can survive as the first fish of a new tank, however this will make them very aggressive towards any new additions to the tank.

Is the Purple Dottyback Reef Safe?

The Purple Dottyback is reef safe. They do not attack small shrimp, crabs or other inverts like starfish, worms or cucumbers. They will go after very young or small worms that are born in the tank but should not harm anything that has been established for awhile.

As for coral the Purple Dottyback typically lives around bright and colorful corals. As its body is made to blend in with these bright settings they do not eat or destroy their camouflage and will happily swim around corals without picking at them or stealing food from the corals. They will even benefit the corals as they eat small worms or pods that would otherwise harass the corals.

One of the main issues they can run into is dealing with clownfish who host an anemone. The Purple Dottyback is very aggressive and may not like the clownfish chasing them away every time they swim by the anemone. Keep an eye on the two fish and remove an overly aggressive dottyback if they are harassing a clownfish that hosts an anemone. It is much more difficult to get a clown anemone combo than a lone colorful fish.

The Purple Dottybacks Diet

The Purple Dottyback is a fairly easy to feed fish. They are carnivorous fish that do well when fed a mixture of high quality flake food, pellets and occasionally live foods like brine shrimp, which can even be gut loaded to increase their nutrition. The more variety you keep in their diet the more colorful they will be. As the age, get stressed or become deficient in some nutrients their color will fade, so a good diet is something easy we should focus on.

A good diet for the Purple Dottyback should contain:

  • High quality flake and pellet foods
  • Dried brine or mysis shrimp
  • Live gut loaded brine shrimp
  • Frozen foods
  • Finely cut meaty foods like squid or table shrimp

These fish do better when fed frequently rather than large feedings. The Purple Dottyback can eat as many as 5 meals a day, which helps simulate their constant feeding habits in the wild. The easiest way to keep them fed is to do two big feedings for the tank and have automatic feeders drop in supplementary foods in between the feeding times. As the Purple Dottyback is a very quick feeder they should get a good amount of the food before other fish move in to get food they may not need. They will do fine when fed two or three times a day but may show loss of colors if they are not able to hunt small foods in the tank like copepods, bristle worms or other tiny crustaceans.

One of the bigger issues the Purple Dottyback faces is their picky nature in new tanks. When first added they are unlikely to eat most foods and can often starve to death before their owner can get them to eat. The easiest way to combat this is using live foods like phytoplankton, brine shrimp or small worms. You can also add bags of copepods to the aquarium, however these are rather costly and will be eaten by most small fish that are kept with the dottyback.

Once they are eating prepared foods it is a good idea to use occasional herbivore foods mixed in with their meaty diet. They do not need a lot of the nutrition that herbivore foods have, so only the occasional few flakes or pellets do great as a low cost supplement. Keep an eye on the herbivore food when feeding the Purple Dottyback as they may simply spit the food back out and never eat it. IF this happens every time you should stop feeding them the herbivore foods.

Finally be careful when adding them to existing tanks that have non competitive eaters. Slow moving fish or those that are easily scared away may have trouble getting food around the Purple Dottyback and can easily wither away if their inability to feed goes unnoticed. Feeding the tank in multiple areas at once can help combat this issue, however in smaller tanks there may not be enough space to keep the fish feeding in separate areas.

Purple Dottyback Tank Requirements

The Purple Dottyback is quick to make a new tank its home no matter how it is set up. The require no less than a 30 gallon tank, with a longer tank being more preferential than a tall tank. They enjoy tanks with a large amount of live rocks to swim in between and hide in when they feel frightened. They will swim around all levels of the tank and around every existing fish, invert and coral. In the wild they will spend a good amount of time in the caverns created by live rocks, being very aggressive towards those who try to enter the caves.

The importance of live rock in the Purple Dottyback’s aquarium cannot be overstated. They will typically hide in these from predators and will feel much more secure with them in the tank, even if there are no predators. Additionally the dottyback is quite aggressive towards fish its own size. They will likely need the live rock to protect them from the dottyback. The most effective way to decrease aggression using live rocks is to divide the tank into multiple sections, breaking the line of sight between the fish.

Both the Purple Dottyback and any fish it chases are high risk jumpers. A tight fitting lid is absolutely necessary to keep them in the tank. All small holes, like those around power cords, overflow boxes and heaters should be covered. Likewise be sure that any overflow box has teeth keeping the fish out of the box and cannot be hopped into.

As the Purple Dottyback lives in high flow areas in the wild they are used to living with high currents that must be imitated using powerheads or wave makers. Using a single powerhead in a small tank with a large amount of live rock is likely to create low flow zones where most of the tanks debris will collect. You can either combat this with a second powerhead or take advantage of it by placing your filtration around there, hoping it will remove the debris before it can settle onto the floor. Caves will always collect debris and there is very little you can do to combat that other than have a clean up crew of sand sifting inverts and crabs.

Purple Dottyback Tankmates

The Purple Dottyback should only be kept with small semi aggressive fish who will not be bullied by them. Adding them to tanks with meek fish like gobies, dragonets and blennies is always a bad idea. They will be bullied frequently and will suffer either from attacks, stress or starvation as they are unable to eat around the dottyback. Also avoid any bright purple fish with long bodies that look similar to this dottyback. They will quickly be bullied no matter their aggression level.

Likewise large, aggressive fish can quickly harass the Purple Dottyback as they are very small and colorful fish. Large fish like groupers will easily eat the dottyback and aggressive, colorful wrasse will quickly kill a Purple Dottyback if they get on their nerves.

Good tankmates are:

  • Dwarf Angelfish
  • Clownfish
  • Cardinalfish
  • Chromis
  • Fairy Wrasse
  • Anthias
  • Damselfish

Keeping two of these fish together is not ideal. The Purple Dottyback is quick to go after similar looking fish and will not tolerate other members of the Pseudochromis family.

They should not harm any established inverts no matter how small but will feed on young worms or crustaceans. This makes them a decent pick for tanks that are having an increasing amount of worms or pest amphipods.

Purple Dottyback Gender & Breeding

There is no way to differentiate between a male and female Purple Dottyback. Additionally they do not breed in the home aquarium. This is hard to understand as their most similar looking dottyback, the orchid, is very easy to breed even in the home aquarium. A big part of them not being bred is their extreme aggression towards others of their kind, making pairing them nearly impossible for the average aquarist. Even a suitable pair of Purple Dottybacks are likely to fight to the death even if they were captured together in the wild.

It is a very common story for people to keep a young pair of Purple Dottyback together for awhile only to have one wind up dead. As they get older they will always fight. Having them both become established while young makes neither of them willing to back down.

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