Dithering Dispar

Almost everyone with a large enough aquarium wants to have some dither fish. This is a term we have borrowed from the freshwater side of the hobby, where small, (generally schooling) fish are used in a display to bring activity to the display with the added benefit of making all the other fish feel safer, and thus are more likely to spend time out in the open (vs hiding in the rocks). Choices for these kinds of fish are limited on the saltwater side of the hobby because they either get too big or get too aggressive (many of our damselfish friends fit in this category). Frequently people go for Green (or Blue Green) Chromis and this is a great choice. For those who want something more striking, with more interesting swimming behavior, the next fish up is usually some kind of Anthias.

Pretty much all Anthias are gorgeous, but only a select few are hardy, stay small, eat well and are peaceful inhabitants of your reef aquarium. One of the best choices a hobbyist can make between all the available species is the Dispar Anthias (Pseudanthias dispar). While nearly always called Dispar among marine aquarists, they are also frequently called Redfin Anthias, Peach Fairy Basslets, Peach Anthias, Orange Anthias, and even just the very generic Fairy Basslet. In Japan they are often called Akane Hanagoi, which very loosely translates as Red Madder Perch. In regard to its scientific name, this fish is categorized in two different genus by the two best known research sites on nomenclature. As of now (August 2023), Fishbase lists it as Nemanthias dispar, while WORMS says that Pseudanthias dispar is the correct name. There has historically been a lot of confusion about the Anthias grouping, and we won't get too deep into the weeds on that topic here, but suffice it to say that “Pseudanthias” actually translates from Greek very roughly as False Pickerel...

Whatever you want to call them, and however you believe they should be classified, Dispar Anthias are a schooling fish, found in groups that can number in the hundreds or thousands. These huge schools are usually found in fairly shallow water, 60 feet or less all over the tropical Indo-Pacific Ocean, though they are replaced by another species, Pseudanthias ignatus, in the Indian Ocean Proper (also a great aquarium fish when properly sourced.) The schools of Dispars generally include many other species of Anthias, and together, they will hover above reef crests in areas of high current where they eat whatever foods float past them (most frequently zooplankton). These larger groups are made up of smaller harems where one male is associated with between seven and eleven females. As males leave these groups (are eaten or die) the most dominant females will turn male and take their place.

Dispar Anthias are very well suited for the aquarium life, given a proper environment and this starts with keeping them in groups. While a male isn't requisite because of their ability to change sex, we do suggest you start with one male and several females. This natural distribution will help them acclimate and save them the stress of trying to work out which female is most dominant. Pair this one male with a bare minimum of three females, with between seven and ten being ideal.

If you do some research on this fish, you'll see many references to them getting up to five inches long, and while the largest fish ever collected was nearly this big, this is a very uncommon size for Dispar Anthias; a much more common adult size is around three to three and a half inches. Regardless, this many fish, even of this smaller size, will necessitate a large aquarium. For a small harem, we recommend a tank no smaller than 75 gallons and four feet long. They do well in tall aquariums and given enough flow don't need a huge amount of space as in the wild, they mostly swim in place. 90 and 110 tall aquariums are great, and like with most aquarium fish, bigger is better. Flow will be big part of keeping your Dispar Anthias happy, you should have flow that is at least 20 times the tank volume, however you want to generate it. As these Anthias come from shallow water, they are accustomed to very bright lighting, and this combination of preferred environmental factors makes them nearly perfect fish for displays that feature small polyp stony corals, and bare bottom displays that don't have sand to blow around. Like all Anthias, they will dart, and this can result in them inadvertently jumping out of the tank, so keep it covered.

Water quality wise, these fish come from clean water, that is very highly oxygenated (remember the flow). As a result, you're going to want to emulate this as closely as possible, with stability at the forefront of your mind. Specific gravity close to 1.025, pH around 8.2, and nitrates under 3ppm. Where this might depart a little from what you are all used to reading is in temperature. Dispar Anthias will be fine in your 78-degree Fahrenheit mini reef, but they'll do better in a slightly lower temp; shoot for the low to mid 70s instead as even just a few degrees make a difference in how much oxygen the water can hold. Some Anthias enthusiasts also force oxygenate with air pumps and stones, located in areas where bubble intrusion to the display isn't possible; places like overflows and sumps are good candidates.

Dispar Anthias are very active fish and have evolved to be pretty much constantly eating. As they hold position in the current, darting to and fro to grab morsels of food that swim by, they are burning calories at a rapid rate. The plus side of this for hobbyists is that this is a fish that is accustomed to eating food without giving that food much of an inspection, because there just isn't time. As a result, they generally segue to frozen foods, and then to pellets very quickly and easily. In house, we start by feeding them a mix of thawed meaty offerings from Gamma Foods. We mix things like mysis, enriched brine, finely chopped prawn and all this is generally taken without much fuss; we mix some of the small Nutramar Complete Pellets in with this and it doesn't take much time for the Anthias to recognize the pellets as food too. We do these two or three times a day, and in the home aquarium we recommend you emulate this, and more wouldn't hurt. The reason we like to get them on a high-quality pellet is because they are nutritionally dense and offer the benefit of being able to use an auto feeder to spread these meals out even more; you could easily feed five times a day if you wanted to!

If you're the hobbyist who wants to go down the Anthias road, there are a ton of choices coming your way, just head to our website and look for yourselves: https://www.qualitymarine.com/quality-marine/fish/anthias/. Dispars are one of the best choices to make here, in regard to hardiness, ease of care, upfront cost and stunning looks. This is one of those fish that just can't be photographed well, their beauty is in their movement and the flashes of iridescence that happen under good lighting and lots of flow. They offer amazing activity and watching the male swoop around, showing off for and herding around a group of females is one of the great displays in home aquariums. Head to your Local Fish Store and ask them for a group of Dispar Anthias from Quality Marine today!