If you’re at all familiar with the world of marine fishkeeping, the royal gramma (Gramma loreto) will be no stranger to you. This cheerful purple and yellow species is ubiquitous in the aquarium hobby, and for good reason: royal grammas are small, peaceful, and easy to keep.
Keep reading to find out everything you need to know about the royal gramma and keeping this colorful fish in your own aquarium!
| Name (Common, Scientific) | Royal gramma, fairy basslet, Gramma loreto |
| Minimum tank size | 30 gallons |
| Minimum group size | 1-2 |
| Temperature | 72-78 °F |
| Salinity | 1.020-1.025 |
| pH | 8.1-8.4 |
| Difficulty level | Easy |
Royal gramma description
Appearance
Gramma loreto may be a small species (it reaches no more than 3″ in length), but it’s certainly not an easy fish to overlook. You’ll recognize a royal gramma, also known as the fairy basslet, by its two-toned pattern, which fades halfway across the body from a bright violet to a deep, golden yellow.
A black streak through the large eye and black eyespot on the dorsal fin complete the royal gramma’s dramatic look.
Royal gramma vs royal dottyback
The royal gramma has a doppelgänger: Pictichromis paccagnella, also known as the royal dottyback or false gramma. Both sport the typical color split of violet on the face and yellow on the tail, which makes it easy to confuse the two if you’re not familiar with them.
Luckily, it’s possible to tell the difference. Firstly, the royal gramma has that black eyespot on its dorsal fin, which the dottyback lacks. And secondly, while the royal gramma sports a gradient between purple and yellow on its mid-body, the royal dottyback’s two hues change abruptly without an ombré effect.
Natural habitat
Gramma loreto is naturally found in the western Atlantic, particularly in the Gulf of Mexico and the Caribbean Sea. Here, the species inhabits coral reefs with a depth up to 300 ft, preferring the safety of rock overhangs and ledges over open waters.
Interestingly, it has been noted by researchers that royal grammas often hang out in their caves upside-down—i.e. with their bellies pointed at the water surface. This probably allows them to stay hidden from predators but still remain a clear view of any food sources, and it’s a behavior that you may be able to spot in the aquarium as well!
Did you know? Although the IUCN Red List currently doesn’t consider Gramma loreto to be an endangered species, it has been found that this species is unfortunately a particularly common prey item for lionfish (Pterois sp.), which are invasive in the Atlantic.
Lionfish cause increased mortality rates and drive local extirpation of native prey
Royal gramma aquarium
Due to their small size, you won’t need a very large aquarium to keep Gramma loreto. A minimum of 30 gallons is generally recommended for royal grammas, preferably a reef tank with plenty of hiding spots in the form of caves and ledges.
Because they prefer more secluded areas of the reef and occur in relatively deep water, royal grammas don’t tend to appreciate overly strong lighting. Like many fish species, they’re known to be jumpers, so be sure to use a tight-fitting lid on your tank.
This is not an overly fussy fish: your royal gramma will do fine in regular reef parameters.
Royal gramma compatibility
Royal grammas are considered a great choice for the peaceful community aquarium. Although they may chase other fish away from what they consider to be their territory, violent clashes are highly unlikely. In fact, your royal grammas are more likely to be the victim: you should avoid keeping them larger, predatory fish.
As with many fish, the shy and peaceful nature of Gramma loreto doesn’t extend to its own species. As such, it’s best to keep them alone or in pairs in order to avoid more serious territorial squabbles! In larger tanks, you may be able to keep a harem of one male and multiple females.
If you’re looking for a species to add to a prized reef tank, you’re in luck. Royal grammas are considered 100% reef safe! They won’t bother corals, nor are they interested in larger invertebrates like shrimp, crabs, and molluscs.
Tip: The royal gramma’s hatred for its own kind extends to any fish that looks too similar to it. As such, you should avoid keeping it with species like the royal dottyback, which looks almost the same. Stock other purple and yellow fish with caution.
Royal gramma diet
These fish are planktivorous, meaning they’ll snack on any small critters they can find. Their diet naturally consists mostly of zooplankton and small crustaceans, although they will also consume larger meaty foods if they can. Getting a royal gramma to eat in captivity is not too much of a challenge, which is another reason they’re so popular in the aquarium hobby.
You should offer a wide variety of foods to keep your royal gramma(s) interested. Most standard frozen foods, like mysis shrimp, will be accepted without issue. The same goes for commercial pellets and flakes. You can even feed live foods like brine shrimp to mix things up!
Did you know? Royal grammas sometimes act as cleaner fish in the wild. They eat external parasites off larger fish, which happily allow them to do so. It’s not common, but it is a behavior you may be able to spot in your aquarium.
Breeding royal grammas
Breeding saltwater aquarium fish in captivity isn’t always easy; sometimes it’s almost impossible. Gramma loreto is an exception! This species is captive-bred on a commercial scale, meaning you don’t have to buy wild-caught fish. You can even get it to reproduce yourself, in your home aquarium.
If you’re looking for a new challenge, you can try your hand at breeding royal grammas. It’s quite a fascinating process: these fish build nests. According to research, the male brings material like macroalgae to a secure cave, and there mates harem-style with multiple females. He takes care of the eggs there until they hatch.
In the aquarium, your main challenge will be to find a matching pair. It’s not possible to visually tell the difference between male and female royal grammas, and since they’re so feisty, prospective couples may end up attacking each other. Closely monitor the fish as you try different combinations.
Once you feel like your two grammas (we don’t recommend more females, as it’s already so difficult to form a single pair) are getting along, you should provide plenty of suitable nesting spaces. Faux caves, holes with rocks, and PVC pipe can all work well. Try to also provide nesting material in the form of seaweed and the like.
The process will go a little like this:
- The male will build his nest from his preferred materials.
- The male and female will swim to the nest nightly, perform a nippy mating dance, and disappear inside to breed.
- After a few days, the male will kick the female out, at which point you may have to remove her for her own safety.
- The eggs hatch after around a week, over the course of several days, in the order they were laid in.
- The challenging part is catching the larvae to rear them. A special larvae-catching device is often recommended.
- Once you’ve caught the baby grammas, move them to their own secure larval tank. Start them off on rotifers and start adding Artemia nauplii when the first batch is large enough. Since the larvae will be of different ages and sizes, you’ll have to offer both ultra-small and slightly larger foods for a while.
- The larvae will metamorphose and become recognizable as mini royal grammas around the 3-4 week mark.
Don’t be discouraged if things don’t work out the first time. Just try again—breeding fish involves a lot of trial and error.
Conclusion
The royal gramma is not a challenging species to keep and it should be suitable for beginners. But what if you feel you lack the experience or the time to set up and maintain your own reef tank? FantaSEA Aquariums is here to help!
We design, set up and maintain aquariums for our clients, both professional and private. Contact us with your ideas today!
Sources & further reading
Böhlke, J. E., & Randall, J. E. (1963). The fishes of the western Atlantic serranoid genus Gramma. Proceedings of the Academy of Natural Sciences of Philadelphia, 33-52.
Freeman, S., & Alevizon, W. (1983). Aspects of territorial behavior and habitat distribution of the fairy basslet Gramma loreto. Copeia, 1983(3), 829-832.
Ingeman, K. E. (2016). Lionfish cause increased mortality rates and drive local extirpation of native prey. Marine Ecology Progress Series, 558, 235-245.
