Top of the Food Chain: Keeping the Emperor Snapper Lutjanus sebae

Author: Brian M. Scott

Lutjanus sebae

(Cuvier 1816)

Perciformes, Lutjanidae

Original name: Diacope sebae

Common names: Emperor snapper, emperor red snapper, red emperor, government bream, king snapper, queenfish

Maximum size: 46 inches (116 cm), 72 pounds (32.7 kg)

Habitat: Tropical marine, brackish. Reef associated, depth 5 to 180 m (16 to 590 feet)

Natural range: Widespread in the Indo-Pacific, Red Sea to New Caledonia and Japan to Australia

Diet: General predator on fish, crustaceans, cephalopods, etc.

Aquarium concerns: This fish is too large for any standard home aquaria

Water Quality Control

As with all large-growing predatory marine species, the emperor snapper requires excellent water quality in order to thrive in an aquarium setting. High-quality water is best established and maintained through large and frequent water changes in addition to the use of a high-powered, high-flow filtration unit and an effective protein skimmer.

The emperor snapper Lutjanus sebae is a remarkably simple-looking yet strikingly beautiful species, highly sought for its hardiness, adult size, and character in aquaria. Juveniles and adults alike make impressive display specimens in properly sized setups. Proper size is the key here, as this fish can reach 46 inches—that’s almost 4 feet—and more than 70 pounds! There are, however, also some other areas of concern with keeping this species healthy in captivity, so I’ll pass along some of the information that I have gathered on this fish over the past 15 or so years of dealing with them.

What to Look For

If an emperor snapper is on your wish list, you’ll need to know what to look for when trying to choose a healthy specimen. As with most “tankbusting” species, this fish is commonly imported as a small juvenile. This is true for two basic reasons. First, juveniles are far easier to collect with a net or other capture device. Second, juveniles are much easier to transport and acclimate to life in aquariums.

An Eating Specimen

However, juvenile emperor snappers need to eat, and this—combined with their ravenous appetites—means that the shipping procedure can be very traumatic on them, since feeding during transportation is not an option. Thus, newly imported specimens may often be slightly emaciated by the time they make their way to dealers’ tanks. As with all fishes, and more so with this species, ensure that the specimen you choose to add to your collection is eating before you bring it home.

Signs of Illness

Additionally, there are a host of other things that could possibly be wrong with a juvenile emperor snapper. Disease (both internal and external infections) is the most common ailment. Of course, inspect new prospects for any sign of illness (i.e., clamped fins, swollen eyes, lesions, string feces, etc.).

Internal Flagellates

Emperor snappers seem to be particularly sensitive to internal flagellates, which infest their digestive tract. The early sign of their presence is the lack of appetite the snapper will display. As the infestation progresses, the feces will become stringy and discolored. Eventually, the infestation will rob the fish of enough nutrients where the fish will perish.

To prevent this from happening, feed the newly acquired snapper with medicated foods for the first week or so while in your aquarium—or better yet, place the snapper in a quarantine aquarium for two weeks. Every new fish should go through a quarantine period in a separate tank set up specifically for that purpose. (Okay, okay, I’ll admit I am also very guilty of not quarantining all my new fishes!)

Feeding the Beasts

It should come as no surprise that the emperor snapper is a strict carnivore. A diet of rich, meaty foods such as shrimp, clam, fish (whole and/or chunked), squid, and other seafood should constitute the bulk of the diet. I would also highly recommend, in addition to a well-rounded meaty diet, that a high-quality pellet also be offered. Since the emperor snapper is so common at such a small size, there should be little to no difficulty in getting these smaller specimens to accept prepared foods.

I have had great success with small sinking foods that are offered to the fish along with their meat-based foods. Additionally, it’s not a bad idea to get in the habit of offering frozen formulations, too.

Most hobbyists will house an emperor snapper with other fishes of similar feeding preferences. While this makes feeding time essentially a breeze by having the ability to throw some shrimp in the tank and walk away, I would highly discourage such a mindset. I have personally experienced recurring feeding issues with emperor snappers of many sizes, and while the largest one that I have cared for was a mere 14 inches or so in total length, that is still a large specimen. And if I recall correctly, he was quite temperamental when it came to feeding time, having fought several failure-to-feed-battles throughout his long life in an aquarium.

Basically, in my opinion and based on my experiences, feeding problems are the single most common ailment that you will encounter with this species.

Room to Grow

As long as feeding issues are kept to a minimum, you will have almost no difficulty in getting emperor snappers to grow in your tank. There is another problem that may arise, however—just how big these fish grow! I would conservatively estimate that of the infinitely small number of emperor snappers that are imported and actually survive their first year in captivity, only about a quarter of them will actually grow large enough to see their colors change from that of a strikingly beautiful juvenile to a bland, but still beautiful, adult.

Making Space

To accomplish such a feat takes space—a lot of space! It would be foolish to simply throw a random figure in terms of gallonage out here and say, “you need a tank of X size if you are to grow your emperor snapper up to adulthood.” That is not a wise approach, nor an accurate one, and I really cannot give carved-in-stone dimensions here that I feel are accurate enough to attach my name to.

One reason for this is because I have seen several specimens grow to half size of about 2 feet in impossibly small aquariums (e.g., 180 gallons). Now do not get me wrong here folks, I am not advocating the use of smaller aquaria to house these beasts, but I will say that I have been surprised on more than one occasion to see/hear that such a specimen was raised for that long in something as small as a 180-gallon aquarium. Now to some, a 180-gallon tank is a huge piece of furniture, but for those of you that are hardcore tankbustin’ fish nuts, a 180-gallon tank is just the filter sump!

How Big Is Big Enough?

The absolute minimum size aquarium for any fish is wider than the fish is long (so it can turn around) and several fish-lengths long (so it has some room to swim before having to turn around). For this species that translates into a minimum of 4 feet by 16 feet. At 4 feet deep that means a 2000-gallon tank!

Perhaps the best way to approach the question of tank size is to simply suggest that you should do whatever it takes to provide the absolute largest aquarium that money and space will allow. This will help ensure that your emperor snapper will have the best home possible. Since I tend to err on the side of caution, I will also throw out a little useful tip here: By increasing the circulation and the size and frequency of water changes, you can mimic the benefits of a larger aquarium. What I mean is that fishes will usually do better, or just as well, in aquariums with good circulation and more frequent doses of clean, new water as those that are housed in an aquarium of slightly larger volume—just something to keep in mind.

Thoughts on Tankmates

When choosing tankmates for an emperor snapper, keep two things in mind. First, any prospective tankmates should be too large for the snapper to swallow. Be warned, however, that emperor snappers are not always aware of the size of their mouths, so even marginal fishes should be avoided. In other words, make certain the tankmates cannot effectively be swallowed!

Second, emperor snappers seem to prefer tankmates that are a bit less rambunctious in terms of rapid, jerky, and random movements. Thus, I would stay away from larger flashy fishes and keep to the pretty graceful fishes like tangs, angels, and butterflies. While I am thinking of it, you might also want to watch potential fin-nipping species, as they would love to have a taste of a juvenile’s flowing fins. There are actually many candidates for tankmates of an emperor snapper, and your local aquarium professional can certainly assist you in selecting the right ones for your setup. Additionally, high-quality online Internet forums are good places to seek advice about fishes like the emperor snapper, too. Whichever outlet you choose to get your information from, just make sure the source is talking from at least a little bit of first-hand experience.

Unique Attributes and Notes

All right, so emperor snappers look cool, maybe they even act cool, but the skeptical fishkeeper may ask, “what else is there about them that make them a good addition for my tank?” Now, while I try not to make a habit of talking anyone into keeping a certain fish, nor even types of fishes, I should at least provide my dedicated readers with some useful and unique points that make this fish interesting or cool, right? Maybe knowing some unique attributes of this species will provide a good excuse for absolutely having to have one in your tank!

  • Did you know that juvenile emperor snappers are commonly associated with sea urchins? I never knew that! Just as clownfishes are commensal with anemones, emperor snappers can often be found swimming amongst the spines of sea urchins. This predominately takes place in shallow, estuarine waters, and is less common in deeper rubble or reef zones.
  • Emperor snappers inhabit a wide range of habitats. Juveniles tend to be found in either shallow coastal bays and lagoons, or on coral reefs. Occasionally, juveniles or subadults can be found in brackish conditions. Adults (those over 18 inches) move into deeper water during warm months and shallow water during the cooler winter months. Adults are usually found either alone or in large schools of same-size specimens—but in captivity, only one per tank, folks; adults in aquaria tend to be rather belligerent toward each other.
  • Several sources that provide care information on this fish indicate that beefheart is an excellent food for emperor snappers. In my (strong) opinion I do not find this to be true at all. I feel that red meats, and foods associated with red-meat animals in nature, do not serve as good fish food. They are often fatty and will make a terrible mess of your water quality. Additionally, since we are talking about a marine fish here, can you imagine what fatty foods would do to your protein skimmer? Talk about a reaction—you’d have a flood of foam!

As a parting note, a common myth about this species is that they are difficult to keep alive. As mentioned previously, I tend to agree for the most part, but only if the juvenile does not feed. Healthy specimens are voracious feeders, and just like groupers and lionfishes, emperor snappers are capable of eating themselves to death—literally.

Does Your Fish Have Proper Food and Space?

Presented here are two main concerns with keeping emperor snappers in aquaria: proper feeding and adequate space. As long as the juvenile, or even adult, specimen is actively and aggressively feeding, there is a good chance that it will do well in your care. That having been said, always keep the diet varied and try not to allow a mindset take hold where you simply just use one or two types of foods because it’s easier that way.

Regarding space, a standard 180-gallon tank is just a starting point if you plan to grow your juvenile emperor snapper into an adult. As with any species of fish, always try and buy the largest aquarium that you can afford and that your floor will hold. Of course, don’t forget that huge tanks still need to fit through the doorway of your home, so be sure to make that measurement before heading off to your local aquarium store to buy that monster tank.

Good luck with your fishkeeping endeavors, and if you have the desire and means to do so, try an emperor red snapper—you might like it!