Small, spectacularly colored fish are always welcomed additions to the marine aquarium hobby, especially those best suited for smaller reef aquariums. In 1988, I wrote an article for my club magazine that was probably the first article in North America to discuss a group of small, brilliantly colored fish known as dwarf basslets or dottybacks (Delbeek, 1988). At that time there were only a handful of wild-collected species available, with those endemic to the Red Sea considered the most coveted and highly prized. Today, dozens of species are available from all over the world, but even more impressive is that the Red Sea species are now readily available as captive-bred animals from facilities such as Oceans, Reefs and Aquaria (ORA) from south Florida; they have also produced hybrids.
Famed author and marine aquarium pioneer Martin Moe even produced a small book describing in great detail his adventures in breeding the orchid dottyback (Pseudochromis fridmani) so that others could learn the techniques to do so (Moe, 1997).
In this article, we will look at five of the most popular species readily available in the trade. Given that there are more than 150 species, it is no small task to narrow this to just five; there are arguably dozens more species that could be argued as “most popular,” but these are my top five picks.
Dottybacks belong to a family of fish known collectively as the Pseudochromidae, and they are related to wide variety of primarily carnivorous families, such as jack, snappers, basslets and groupers, to name just a few.
Within the Pseudochromidae, the vast majority of species kept in marine aquaria belong in the subfamily Pseudochrominae. They are distinguished by have a long continuous dorsal fin with only one to three spines, and the pupil of the eye is usually pear shaped.
Within this group are 24 genera, within which there are currently 100 recognized species, which were completely revised by Tony Gill in 2004. While there are several really cool fish within these 24 genera, the two genera that contain the most commonly kept and popular dottybacks are Pictichromis, the magenta dottybacks, and Pseudochromis, the common dottybacks; it is within these two genera that my five most popular species reside.
These are primarily small fish, rarely exceeding 3 inches in length, but a few can reach 8 inches. As mentioned previously, many are brightly colored, often possessing striking color patterns; some species even exhibit sexual dimorphism e.g. Cypho purpurascens, Pseudochromis cyanotaenia and P. jamesi, to name a few (Michael, 2004; Randall, 2005).
Distribution and Natural Habitat
Dottybacks have a wide distribution from the Red Sea eastward to Samoa, and south to Australia and as far north as southern Japan (Randall, 2005). In the wild, dottybacks are secretive fish of coral reefs, rarely straying far from cover.
In Palau, I have seen the magenta dottyback (Pictichromis porphyrea), mainly along vertical drop-off walls; in fact, they were very common below 40 feet, but they stayed close to the walls, darting from crevice to crevice.
In the Solomon Islands and the Lembeh Strait in Indonesia, I observed the royal dottyback (Pictichromis paccagnellae) in a similar habitat, but both were approachable if done so slowly. In the Solomon Islands, I have seen the oblique-lined dottyback (Cypho purpurascens) along shallow drop-offs and even tide pools, darting within the rockwork of coral walls and overhangs. In the aquarium, and in the absence of larger predators, dottybacks will show themselves more frequently, but always with an eye on a bolt hole to retreat into.
Dottybacks are very hardy fish given their size. They feed readily and ship well. They do not prey on desirable invertebrates (with a few exceptions noted elsewhere) and are, therefore, ideal fish for a reef aquarium. They are relatively disease-resistant, but if they contract one of the more common diseases, such as Cryptocaryon, they tolerate the standard treatments fairly well. Some species can be aggressive to other fish in the tank, especially if they share a common color pattern (e.g. royal dottyback and the royal gramma, Gramma loreto), and larger species should be kept with larger more active fish.
Dottybacks are not sensitive to water quality, and the normally accepted ranges for marine aquaria of ammonia, nitrate, temperature and pH are fine. Provide temperatures between 75 and 80 degrees Fahrenheit and a pH of 8 to 8.3.
Scott Michael (2004) mentions that species differ in their tolerance to low oxygen levels, with those from tide pools being the most tolerant and those found along steep drop-offs being less so. If you are fortunate to obtain a species found in deeper waters then temperatures should be kept between 68 and 74 degrees Fahrenheit, depending on the locale of collection.
Part of the appeal of this group of fish is that most of them stay relatively small and are adapted to move within tight spaces. This makes them ideal for smaller reef aquaria and nano tanks. However, as we shall see shortly, only one per tank may be possible for most species, while larger reef tanks (>200 gallons) offer the possibility of housing several specimens of the same species or single specimens of a variety of species (Michael, 2004). While not usually jumpers, if startled by a sudden movement within or outside the tank, or by lights shutting off, there is the chance of them jumping out, especially from very small tanks. In this case, a tank cover or a tank with broad inner lip would be advisable.
In the wild, dottybacks prey on a variety of items such as microcrustaceans and polychaete worms. In captivity, they will take a variety of prepared and fresh foods, such as marine pellets, finely chopped shrimp and clam, bloodworms and blackworms, frozen mysis and other frozen commercial food mixes now on the market.
Being predators of microcrustaceans, dottybacks will also graze on the infauna of the tank, seeking out amphipods, mysis, copepods and, in the case of the largest species in the genera, Labracinus and Ogilbyina, ornamental shrimp such as Thor spp. and Lysmata spp. The Red Sea species are particularly adept at hunting down small bristleworm polychaetes and can be an effective biological control if the population of these gets out of hand (Delbeek and Sprung, 1994).
The species with bright purple and pink colors, such the magenta dottybacks (Pictichromis spp.), are prone to fading in color, which is most likely a reflection of a lack of necessary pigments in their diet. Offering a variety of foods, including feeds with color-enhancing compounds, may help to prevent this. I also wonder about the level of light these fish are subjected to in today’s reef aquaria and whether this has an effect on cryptic fish, such as dottybacks, who spend the majority of their time in nature in crevices along drop-offs and overhangs, out of direct sunlight. It is possible that the bright lights in an aquarium cause their natural pigments to fade.
By nature, dottybacks are extremely territorial, so much so that they need to be held in separate cubicles in wholesale and retail sales aquaria (Fenner, 1998). Unless they are a mated pair or in a larger aquaria, and even then there are no guarantees, one dottyback per aquarium is recommended. The lone exception appears to be the orchid dottyback, but more on this fish later.
As far as tankmates go, smaller peaceful fish, like blennies, dragonets and gobies, may not fare well with a dottyback; adding the dottyback as the last addition to the tank can sometimes help to minimize territorial behavior (Fenner, 1998). The larger, more-aggressive species, Labracinus and Ogilbyina, should only be housed with larger fish, such as surgeonfish, large angels, triggers and more aggressive damselfish.
As more information has become available regarding dottyback reproductive biology and behavior, breeding projects have gained in popularity. Dottybacks are a family of fish that display sequential hermaphroditism. This means that they are born one sex and then change to another as they mature.
There are two types of sequential hermaphroditism: protogynous and protandrous. In protogynous sequential hermaphroditism, the fish is first female and then changes to male as it matures (e.g. anthias). In protandrous, the fish is first male and then becomes female (e.g. clownfish).
Interestingly, dottybacks contain examples of both; although most species of dottyback are protogynous, a few are protandrous (e.g. Cypho purpurascens). In protogynous species, the males are larger, and in the protandrous, the female is larger. A number of species also exhibit sexual dichromatism, where there are profound color differences between males and females.
Dottybacks are usually solitary, but they will pair up for spawning. Some species, such a Pseudochromis fridmani, are haremic. Males will use a small hole leading to a chamber in a rock or shell as the nesting site, and they then go through an elaborate sequence of chasing and trying to lure a female into the nest, where the eggs are laid and fertilized. The male then tends to the eggs until they hatch. The female does not stay.
An egg mass is held together within a network of sticky threads until hatching occurs after five to six days, depending on water temperature. Once hatched, the young can be raised on rotifers, copepods and eventually Artemia nauplii.
As mentioned previously, commercially available dottybacks are now available, but these are primarily the Red Sea species or other difficult-to-obtain species. The sheer cost of rearing fish makes it near impossible to compete on price with wild-caught animals of the more commonly seen species.
Top 5 Dottybacks
I’ve based the following selection on availability and heartiness. Three of my favorites are from the Pictichromis genus.
There are eight species of Pictichromis, three of which I would consider amongst the most popular in the aquarium trade. All three possess brilliant pink/purple coloration, two of which combine this with yellow. What is interesting is that when viewed at depths below 40 feet, the purple actually appears a brilliant blue due to the absence of red light at those depths.
My last two picks are Pseudochromis species and are spectacular in color as well.
1: Diadem Dottyback (Pictichromis diadema)
Found from Malaysia north to the Philippines in the western Pacific, and commonly imported from the Philippines and Indonesia, the diadem dottyback is primarily yellow with a bright magenta strip running from the top of snout over the head and along the base of the dorsal fin to the tail. In some specimens, a white line separates the yellow from the magenta, and this may be sexual difference (Michael, 2004). One of the most commonly imported species, they are found along reef slopes and under overhangs from 15 to 80 feet, and among coral rubble.
Even though the diadem dottyback reaches only 2½ inches, it is among the most aggressive of the dottybacks and should not be trusted around smaller gobies, dartfish, damsels, grammas or even cleaner shrimp (Michael, 1999). One per aquarium is recommended, but it can be kept in small groups in larger tanks with sufficient surface area and cover.
2: Royal Dottyback (Pictichromis paccagnellae)
The royal dottyback is found in the western Pacific from Indonesia north to the Philippines and as far east as Vanuatu. It is typically found along drop-offs, beginning around 40 feet, darting in and out of small crevices, pausing for a few seconds in the open before speeding off to another crevice. They closely resemble the royal gramma (Gramma loreto) in coloration, with a purple anterior and yellow posterior, but the purple and yellow coloration does not extend onto the fins to the same extent as in gramma. Reaching a maximum length of 3 inches, this species is commonly imported from the Philippines and Indonesia.
Some Indonesian specimens sport a vertical white stripe between the purple and yellow portions, but it is not clear if this related to sexual dimorphism or if it represents a variant (Michael, 2004).
Specimens out of Australia used to be classified as P. paccagnellae, but during a revision of the family, Gill (2004) named this as a new species based on some slight anatomical differences and genetics, called the bicolor or Coral Sea dottyback (Pictichromis coralensis). For the hobbyist, the easiest way to distinguish this species from the royal dottyback is the slight larger size as adults and the fact that instead of a vertical demarcation between the purple and yellow portions of the body, the bicolor has an oblique demarcation.
A highly recommended fish for the beginner, P. paccagnallae are extremely hardy and disease resistant. However, this species can become extremely aggressive toward others of the same species and other pseudochromids, basslets, gobies, dartfish, mandarins and docile species. It appears that the closer the other fish is in color to P. paccagnallae, the greater risk of aggression (Delbeek, 1988).
3: Magenta/Purple/Strawberry Dottyback (Pictichromis porphyrea)
One of the more widespread of the dottybacks, the magenta dottyback is found from Samoa to Indonesia in the west and from southern Japan down to Fiji (Michael, 2004). This fish is most commonly imported from the Philippines and reaches a maximum size of 2½ inches.
It is slightly less aggressive than the royal dottyback, and can even be kept in pairs in tanks of 75 gallons or more (Michael, 2004). However, add this fish with caution to a tank that houses smaller docile fish such as gobies, mandarins and dartfish, as it will bully them.
The magenta dottyback is one of the species most prone to color loss. This may be circumvented by feeding a well-balanced diet of meaty crustacean-based foods, such as krill and copepods, as well as diets with color-enhancing pigments, including astaxanthin and other carotenoids.
4: Orchid/Fridman’s Dottyback (Pseudochromis fridmani)
Named after David Fridman, one of the founders of Coral World in Eliat, Israel, this species is endemic to the Red Sea and is arguably one of the most beautiful of the dottybacks in my opinion. Reaching a maximum length of 2¾ inches, this species closely resembles P. porphyrea in color, being totally purple, but the purple color extends onto the fins too. It also has a black line through its eye.
A peaceful species, this is one of the few dottybacks that can be kept with smaller peaceful species and can even be kept in small groups. It is found in small groups of eight or so fish in nature, usually in a fairly small area (Michael, 2004). The orchid dottyback also tends to its hold color without much attention to diet.
This species has been bred in captivity by hobbyists and is available from commercial operations. There have been various things written over the years about sexual dimorphism in this species, including the fact that males tend to be larger and more elongate with an elongated lower lobe of the caudal fin, while the females are smaller and plumper.
5: Springer’s Dottyback (Pseudochromis springeri)
Also endemic to the Red Sea, this species is one of the smaller ones at a maximum length of just 1½ inches. The body can range from black to grey, with two brilliant-blue lines running above and below the eye along the head. It is thought that this coloration may mimic that of the Red Sea cleaner wrasse (Larabicus quadrilineatus), thereby offering some sort of protection via mimicry (Michael, 2004).
This is the first dottyback I ever kept and, at that time (1989), the only one in Canada. Today, this species is available as tank bred and at much more affordable price than what I paid! This is one of the more peaceful species, and can be kept as a pair. It is prone to jumping; an aquarium cover should be employed at all times. This dottyback can be found in a variety of habitats, from turbid inshore waters to clear offshore reefs amongst branching stony corals (Michael, 2004).
A Beautiful Addition to Your Tank
This concludes our look at five of the most popular dottybacks. With more than100 species to choose from, I am sure many of you have your own top five choices! For sheer beauty in a small package, there are not many fish groups that can compete, and it is easy to see why these fish are amongst some of the most popular for any size of marine aquarium.
Charles Delbeek has cared for marine organisms in closed systems for more than 43 years and has lectured at more than 80 aquarium-related conferences and meetings, He has chaired several professional conference sessions and published more than 130 articles in the popular aquarium and scientific literature, including three popular aquarium books with Julian Sprung, The Reef Aquarium series, considered by many to be the definitive works in the field. Charles provides consulting services through his company, JCD Consulting (jcdaquariumdesign.com), to public and private aquarium projects around the world.