Aquarium Fish: Large Angels in the Home Aquarium, Part 1

by | Jan 15, 2008 | 0 comments

Thinking of purchasing an Angelfish? Then this article is just for you. Similarly, if you’ve attempted to keep one of these magnificent animals in the past only to encounter problems, then the next few pages should help tremendously. Of all the fish that can be found on a tropical coral reef, there is nothing more majestic than angelfish. Indeed, if my experience over the past few decades dealing with and helping people in this hobby is any indication, this group of fish is near the top of the list in popularity. Although definitely not for everyone, this doesn’t stop just about every marine aquarist from lusting after and trying their hand at keeping one of these beauties in his or her living room at some point or another in his/her fish keeping careers. The results as with any species can run the gamut, but there are concerns with these genera that I think warrant a detailed look.

The information in this article is by large the result of my 22+ years of experience observing these animals in my own tanks, as well as tracking the results obtained by other hobbyists during that time. I’ve had plenty of time to learn what does and does not work, both under my care and that of others. Success with these fish cannot be measured in months, or a few years. These fish can live for over 20 years in captivity; therefore only long-term results are salient when discussing what is best for their well-being. For the most part, this article is not the result of research, but hard earned empirical knowledge.



A resplendent Pomacanthus imperator adult. Photo by Teresa Zuberbühler,

On with it then!

Just like the freshwater ones right?

Not exactly, in fact not even close. Freshwater angelfish belong to a group of secondary division freshwater fish (close lineage to marine fish) known as the cichlids, which also contain popular aquarium fish such as the Oscar and Firemouth. While both the marine and freshwater angels belong to the order perciformes, and share a vague, tall bodied, laterally compressed similarity, the practical resemblance ends there.

Marine angels can be the length of your little finger or as large as 24 inches. They can be muted, garish, or anything in between. They are intelligent, and like the groupers and triggers that I’ve written about previously, they have loads of charisma and personality. The large angels that we will be discussing here are also rather robust as adults, despite a somewhat delicate, often butterfly-like nature when young.


Pomacanthus imperator in it’s juvenile colors. Photo by Teresa Zuberbühler,

What do I need to know?

Plenty! This article will be in 2 parts, and a little long-winded compared to the previous two on hinds and triggers, simply because there is much more than needs to be said. When considering purchasing one of these fish, you have to know your stuff, and you have to be prepared! These animals are by most measures one of the less forgiving families available to the marine fish keeper, and this unforgiving nature manifests itself in a variety of ways, including space requirements, nutritional requirements, temperamental considerations, and usually a combination of the three. This of course varies drastically with genus and species. There is too much variation and too many idiosyncrasies within this family to impart all necessary information here, so this article will not, and cannot be the extent of your research. However, I’ll attempt to give an overview of the family, and the must do’s and don’ts in order to help you keep these fish successfully. With regards to specific species, I’m going to speak in terms of what the hobbyist is likely to encounter with regard to hardiness and temperament for that species. Nothing is all the time, and you may have a stroke of luck with normally fragile species, or have a string of bad luck with a species that is generally trouble free.


Pomacanthus asfur – juvenile.

The most important thing to keep in mind with regard to marine angels is that they do not suffer a lazy keeper easily – they are for advanced keepers with the resources to give them what they require to thrive. In the grand scheme of things, when compared to many other fish species that are available, they are decidedly on the delicate side. This tendency is understated not only in most articles and books in my opinion, but by many keepers as well. This I believe is because many mistake a living fish, with a thriving fish in resplendent health. They see a fish swimming around still after a year, or 4 years, and assume all is well. Often in fact this apparently healthy fish is heading towards doom, even though it may not show outward symptoms of disease or stress. Below I will examine further why this is, and how to mitigate the potential problems. For now it’s enough to say that the keeper who neglects his initial research, fails to quarantine his new arrival, fails to give his charge the proper nutrition, the proper space, or fails to perform adequate maintenance on the tank itself is asking for problems. So, let’s get down to business and figure this family out!


Do I have the space?

As the title of this article indicates, by home aquarium standards these are large fish. This is a subjective term of course, and adult size varies from 6″ to 20″ or so in the wild depending on species. While adult size in the wild doesn’t necessarily translate into size attained in the home aquarium under average conditions (more on this below) you can easily choose a species that will be very at home in your 80 gallon, or very, VERY cramped in a 200 gallon tank if you’re not careful. So the first thing you need to determine is what species your tank will accommodate in the real estate department. Given the diversity of the family, and the varying growth rates and sizes of various species, coupled with conditions that vary greatly from one living room to the next, generalizations are difficult at best here. To further complicate this matter, some angels will attain a size close to their wild adult maximum under the right conditions, while others almost never reach full size in most living room tanks, even relatively large ones. As a general rule, and I stress that this is a generalization, most larger species can be expected to eventually attain half to three quarters of their maximum wild adult size under very favorable conditions. Most of the time, growth also slows as size increases, and appears to all but stop at various sizes depending on species and conditions at hand. This is due to stunting, and is a problem not dealt with in most publications with regards to this family.

The fact that minimum tank size is often grossly understated for most species in some trusted sources doesn’t help matters either. I will stress the previous point by saying that some very popular, current and often-referenced material is preposterously off the mark with regard to tank requirements for these fish, including just about every reference you’ll find on fish retailer websites. In short, the tank sizes given insure a stressed and possibly stunted animal, and therefore the accompanying health issues and shorter life span that comes along with it. A German Shepard will live in a 10′ by10′ room for years, and he might look just fine for the most part during that time, but would you subject the animal to this? I’m betting you wouldn’t. The conditions many keepers subject their fish to, often from the guidance of local fish stores, books, or fellow keepers posting in online forums is tantamount to exactly this.


A juvenile French Angel, P. paru.

What happens when you keep an angel in a tank that is too small? In short, you induce psychological and physical stress that has profound effects on the growth, color, immune response, and life span of the fish. In a physiological sense, cramped surrounding encourages stunting, which in extreme cases affects muscle and organ development, and leads to a dead fish well before it’s lifespan is reached. Minimally, a tank that is too small prohibits these fish from reaching their full majesty not only with regard to size, but some species will not attain full adult coloration, or the adult colors will be lackluster compared to wild specimens. (Diet plays into this too, more on that later).

It’s unfortunate that many aquarists do not appreciate the psychological stress that cramped surroundings create. Some species adapt to a confined environment with no apparent ill effects, at least not in the first years of life. Angels do not fall into this category however. Aside from the buildup of growth limiting substances that cramped surroundings encourage, psychological stress stunts growth in a huge way as well. More importantly in the short term -it breaks down the immune response, which will invariably lead to disease. While often we see disease almost immediately due to this stress, these effects are not always apparent at first, and make take weeks, months or even years to become evident, again depending on species and circumstances. A tank might be too small because of the size, or eventual size of the angel, or it might be too small because of tank mates that you’ve chosen to keep with your angel. Forcing an angel to cohabitate with aggressive species, especially without allowing enough room for the angel to escape the aggressor’s attentions is a recipe for trouble. In any case, the results will be the same for the angelfish eventually. Further, what would be an acceptable sized tank for a 10″ trigger is not necessarily an acceptably sized tank for a 10″ angelfish. This is simply because the Pomacanthids are generally more prone to the psychological stress that comes with going from the infinite ocean to the confines of a glass box. Remember, an angelfish in the wild often maintains a territory as large as the lot that your house is sitting on! In short, they need more physical space than you’re probably used to providing, and certainly more than most wishful thinking in current literature indicates.


Pomacanthus semicirculatus – adult. Photo by Teresa Zuberbühler,

So what does all of this mean in actual practice? While some of the Chaetedontoplus species will live long term in quarters as small as 80 gallons, most Holocanthus and Pomacanthus species require at least a 250 to 300 gallon tank to live a proper life span in optimum health. If this sounds ridiculous, think of the size difference between a tennis court and an 8′ aquarium. I think asking the fish to adapt to the 300 gallon tank is quit enough, don’t you?

Let’s look at a popular, easily obtained species – the Koran Angelfish, Pomacanthus semicirculatus. This species attains a maximum adult size of 15″ or so in the wild. Now, most literature will tell you that you need anywhere from a 100 to 135 gallon tank as a minimum to maintain this species. Not so fellow fish keepers! Will a juvenile Koran live in a 135-gallon tank for quite some time? He sure will. Will he live for 20 years, reach his full adult size and thrive? Most definitely not – he’ll most likely become stunted and eventually, sick. A more appropriate long term home for this species would be in the 200-gallon range, or even better, 300 gallons. Having said this, this is one of the species that will suffer least from such treatment. Other species that are often lumped into the “minimum 135 gallon tank” category will suffer to a greater extent, both in ways that are, and are not readily apparent, and often simply wither and die for reasons typically unbeknownst to the keeper. To see the Emperor or Queen angel sited as needing such meager quarters is just ridiculous. An adult Queen angel, by the time fin trailers are measured pushes 2 feet, a 135-gallon tank is typically 18″ wide! The Annularis Angel pushes a foot in length, yet many would have you house it in a 100 or 120 gallon. The Emperor Angel attains almost 18″ – again, the idea of a 135-gallon tank is just silly.

The justification that the fish will not attain adult size in captivity, and therefore not require such a large tank is erroneous and indicative of poor husbandry philosophy. The health of the fish kept under such methodology will suffer sooner or later. There are fish that do not suffer as greatly from such an approach (within reason) such as the triggerfish, or many grouper species. While a genus or species being generally forgiving in this regard should not be interpreted as license to cramp them into tight quarters, the Pomacanthids offer no such level of forgiveness. They eventually and invariably show faded color, and/or withering health, and begin a long, (or not so long) downward spiral. If that all sounds discouraging, no worries, the good news is that you can split the difference between a small inland sea in your living room, and a tank that is too small to allow for a long and healthy life for your angelfish. The bottom line here is that you will have greater success the more room you provide from the get-go, even beyond the sizes I’m about to list. This means that despite it’s small size, a 3″ juvenile Queen angel will do much better in the long run starting out in a 180 gallon tank than it will an 80 gallon tank, even though from a space perspective, 80 gallons would seem large enough for the time being, and certainly would be for a 3″ Hawkfish. Remember, we’re concerned just as much about the psychological effect of the environment at this point, and by extension we are managing the stress level, immune response, growth rate and color of our specimen. When upgrading to something larger, do so before he’s starting to look too small for the 180 gallon, say around 6″ or so. To reiterate, artificially stunting these fish by keeping them in inadequate quarters is not appropriate husbandry practice, despite how common this practice is, whether it be from ignorance, or lack of space, or limited finances. While the above statement moves a majority of aquarists out of the realm of being able to keep these fish, considering the frequency with which these fish die under the care of well meaning but ill-equipped hobbyists – I think this is justified. This family is without a doubt for advanced keepers in multiple respects. Just because a fish is collected and imported, does not mean it’s appropriate for your living room. The aquarist must be, above all things, conscious of the well being of the animals he/she keeps.

As stated before, these fish generally do not grow quickly, even under the best of circumstances, but some species will buck this slow growth tendency, even in less than adequate surroundings, such as Pomacanthus paru, the French Angelfish. This species will not only grow large, it will do it rather quickly, often going from the size of a half dollar to the size of a dinner plate in a year. While I haven’t personally seen any other species grow quite this quickly, that doesn’t mean it’s not possible. By large though, fish belonging to this family are relatively slow growers in captivity when provided with typical accommodations, and for the most part they will not reach full adult size in tanks that are available or affordable to most hobbyists.


How do I select a healthy specimen?

As with any marine fish, selecting your specimen is where your success or failure in keeping the animal begins. This is easier said than done of course, as the fish has been through quite an ordeal by the time it reaches your local retailer. All things being equal, the general effect of this ordeal varies from one genus or species to another. As mentioned above, the Pomacanthids are among the most sensitive species of fish to stress. The rigors associated with capture (often with cyanide), being held with little or no food, then being shipped halfway around the world in a bag is taxing to even the most robust species.

So, what do you look for? In short, a flawless, alert looking specimen. This means no sunken regions on the body, either on the dorsal or ventral regions. Fins should be intact, with no light or discolored patches on the eyes, fins or body. There should be no sores, pits or lesions of any kind along the lateral line, or anywhere on the fish. Angels often turn sideways to maneuver through holes or crevices in rocks or coral – aside from this exception, the fish should be swimming upright at all times. The specimen should show awareness of your presence, even if this means it insists on hiding behind something to avoid you, which is quite common with some species. The fish should of course show good color!

As with many species, you should also avoid specimens that are too small. Anything under 1.5″ is not likely to be sturdy enough, or eat enough to enable it’s survival beyond a week or two. Likewise, avoid larger specimens above 6″ or so, as they are unlikely to adapt to captive foods and conditions. Always ask to see the little guy eat, but be aware that many specimens will be much too stressed to take any food in the store’s holding tanks. Still, if given the choice between two identical, healthy fish, take the one that eats -it will ease the acclimation process when you finally get him home.


One more thing…location, location, location!

Specifically, the location that your angel fish to be was collected from. Unfortunately, the use of Cyanide to collect marine fish is still prevalent in many regions. Fish that are stunned, or “juiced” with cyanide during collection, and survive the initial exposure (many die outright) have been shown to have an extremely high mortality rate 55.9% to 61% 40 days post-importation. (Jay Hemdal pers comm.) Worse, the fish often appears normal, even spectacular when viewed at the fish store and may even eat well, only to “crash” a few weeks, or even months later for apparently no reason. I have seen at least 2 authors call into question the validity of studies attempting to prove the long-term effects of cyanide on marine fishes, and I commend any effort to add to our knowledge base. However at the same time they do acknowledge that concentrated exposure to cyanide is most definitely deadly to marine organisms, and there are other more recent studies that validate delayed mortality after cyanide exposure. Even if the specific long-term physiological effects of cyanide are still unclear on fish that initially survive exposure, it’s clear that cyanide is a poison, and in high concentrations it kills fish outright. In my opinion, the need to debate the issue ends there. When dealing with toxins, there are very few examples of “X-amount kills instantly, but Y amount has no ill effect”. It’s the belief of this author based on 22 years of observation at all levels of the hobby, that at least some seemingly inexplicable deaths post-capture are caused by cyanide poisoning. My advice is to let others poke holes in published graphs and charts, and do your best to stay away from cyanide caught fish – period. At the very least, the additional physiological stress and negative health effects that this method most likely brings on are not something our angel friends suffer easily. My own empirical data on Pomocanthids caught in regions such as the Philippines where cyanide fishing is rampant supports this contention.


The Queen Angel, Holocanthus ciliaris.

Where does this leave you? For starters, from time to time captive reared angles are available from online dealers. These are usually captured larvae that are reared in pens or tanks, and are most suitable for the aquarium. At the time of this writing, I’ve been unable to verify the legitimacy of the current captive reared offerings out there, so proceed with caution. Investigate thoroughly before purchasing! Lastly, and most importantly, you can arm yourself with research as to where cyanide fishing takes place, which locations are cyanide free, and where your prospective new aquarium inhabitant hails from. This way not only can you be sure for instance to avoid an Emperor angel that was collected in the Philippines, if the store employee tells you he’s from Mexico, you know you’re not getting accurate info, and to steer clear of that fish. Any reputable dealer will know where his fish come from!

A good place for information on locality for just about any fish species is and a bit more technical, Up to date information regarding where cyanide fishing is taking place, and what areas are safe is a bit harder to come by. The following is a list of localities that are known more or less safe from cyanide use.

The Red Sea, Australia, the Cook Islands, Sri Lanka, East Africa and Fiji (Jay Hemdal pers comm.), as well as Papua New Guinea, Mexico and Tonga, (Gresham Hendee, pers comm.)

This is not necessarily a complete list, nor am I contending that every fish from everywhere else is doomed to die from cyanide poisoning. I’ve purchased plenty of fish from “unsafe” zones and did just fine with them. The point is that you need the variables on your side, and ending up with a “juiced” fish is a good one to eliminate, especially with this family. Cyanide fishing is the most rampant now in Indonesia/Bali, with the Philippines coming in a close second. (Steve Robinson, pers comm).

One final note on cyanide, and that is the damage this practice causes not only to the environment, but also to the indigenous peoples in the regions where this practice occurs. Most fishermen are not tropical fish catchers, yet they all lose when habitat is destroyed by cyanide fishing – resulting in poverty and genuine suffering for these populations. (Steve Robinson, pers comm.) As aquarists, we are the least of the victims. For these reasons alone we should strive to avoid purchasing fish collected with this toxin.

Next issue, we’ll look at further husbandry requirements, including acclimation, compatibility and stocking methods, as well as diet and species profiles.


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