their desirable appearance as they age. Some actually turn completely brown or black when they are mature, and some of them can get much bigger than you might think. Several species that are often seen at shops at one to two inches in length can grow and grow until they’re the biggest fish in a tank at times (depending on what else is in the tank, of course). Wouldn’t you hate to buy a beautiful two-inch damsel, only to have it grow into a very plain black six-inch fish? A few species can get even larger, too.

Still, these are trivial issues compared to the absolutely nasty attitudes many damsels have. Even at small sizes, these fishes are often territorial in nature, and can decide that a significant section of a large tank is their territory, or that everything within a small tank is. They’ll defend what they consider to be their own real estate, even against peaceful fishes that are much larger than they are, to the point of pestering them to death. Such damsels will chase and nip at practically any fish that doesn’t have the guts to fight back, and you’d be surprised at how many larger fishes won’t. If this persists, the victim will often become so stressed since there’s nowhere to move on to, that they’ll hide all the time, may end up sick, and might even die. Really big damsels have been known to outright murder smaller fishes.

Speaking in general you should never try to keep more than one damsel of the same species together unless they have plenty of room and hiding spaces. For that matter, it’s usually a bad idea to mix different species in confined quarters, too. Remember, they can be very ter-ritorial, and another damsel, regardless of type will typically be seen as a direct competitor for space. However, some can be kept in schools at times, and the same goes for the chromises. In fact, the popu-lar chromises are best kept in groups and will stick together and swim around in a pack near the top of a tank.

I’ll also add that while they typically won’t bother invertebrates, there are some species that will snack on tiny worms and crustaceans that are quite beneficial in some tanks, especially those that have deep sand beds. Little things like amphipods and copepods will make quick meals for some of them.

Some Common Species:

There are lots of damsels and chromis-es, but I’ve listed a few common ones below. Just enough to give you a good idea of the variability found between the species, and what may or may not

Abudefduf vaigiensis, the sergeant major damsel:

Named for its sergeant-striped body, these damsels and their close cousins can be spotted on just about any dive, wherever there’s warm water.This is one of the species that looks cute when small, but can grow to a whopping 8 inches and may eat small invertebrates if given the chance.

be a good choice for your aquarium. Keep in mind that how common a species is at a shop, or how popular they are overall, has little or nothing to do with how suitable they are for a reef aquarium. Many of these are no good for reefers, even in large aquariums.

Chrysiptera cyanea, the blue devil damsel:

Awesome blue, but called a devil (and a lot of other words that I can’t write here for good reason.) They only reach about 3 inches at best, but when it comes to nastiness, these little things can be real terrors. I’ve added these to reef aquariums in the past, and regretted it on every occasion. So they’re off-limits now in my book, no matter how cheap, tough, and pretty they are.

Of all the fishes available to marine aquarists, I’ll bet that none have

been added to tanks as often as damself-ish have. Some species are as colourful as a fish can be, stay relatively small in size, can get along well with other fishes and invertebrates, and are inexpensive, too. However, the key word here is ‘some’ species, rather than all of them. Despite the general popularity of these fishes, many can be absolutely nasty towards their tankmates. Some get much, much bigger than you might think, and some get quite plain looking or even ugly as they age, too. So, this clan of fishes certainly merits a closer look.

What are they?

Damselfish are the members of the Family Pomacentridae, which contains over 300 species altogether, some of which are without a doubt the most popular fishes in the marine aquarium hobby. Almost all of them are marine, primarily being found in the Indian and Pacific Oceans, but there are a few that may be found in brackish waters, and several species that are found in the Car-ibbean Sea and Atlantic Ocean, as well.

Most of the members of the family are simply called damsels by hobbyists, but some members are called chromises, all of which belong to the genus Chromis. The clownfishes, which hang around in anemones and belong to the genus Amphiprion or Premnas, are also in the same family with the rest of these, too. But, we’ll be sticking with just the “regu-lar” damsels and the chromises here. Clownfish, despite being in the same

family, are unique enough to warrant full-coverage in their own article.

The good things about them:

There are quite a few good things to say about the damsels and chromises. Many are very colourful, and some actually seem to glow under bluish-coloured aquarium lighting. Even those that are covered only by black and white stripes and spots can be really attractive. Many also stay relatively small, even when full grown, which is very desirable to most reef-keepers. In fact, quite a few of them won’t get any larger than two or three inches at the most. I’ve provided the maximum reported sizes for several species below (from www.fishbase.org), but keep in mind that these are exactly that – maximums. Most specimens won’t get so large in aquariums, and are often considerably shorter in length even when perfectly healthy and well cared for.

Some will get along well with other individuals of the same species, and with other species of fishes, too. Many can even be kept in groups of several individuals, which will move around larger tanks in schools. And, almost all of them will leave alone whatever sorts of non-fish life you have.

On top of all that, the damsels (but not so much the chromises) are categorically tough. Very hardy indeed, so much so that they have been the number one type of fish used to cycle new aquariums for as long as they’ve been available, as best as I can tell. Less than stellar water qual-ity is seldom a problem for them, and

most will survive the process of establish-ing the biological filtration cycle in a tank in stride. They aren’t bulletproof, but compared to other sorts of fishes, they’re certainly ranked high when it comes to survivability under adverse conditions.

Most of them will also eat just about anything that you add to a tank that is considered fish food. Flake food, brine shrimp, blood worms, fine bits of fish, clam, and squid meat, sheets of algae, frozen cube foods, etc. Most of them will take it all, and will nibble at some of the unwanted algae that grows on rocks and such, too.

And, as if that’s not enough, they’re cheap. Marine fishes are quite expen-sive compared to freshwater fishes, but damsels and chromises can still be picked up for just a few pounds at any shop you might visit. Thus, there are lots of reasons to like them.

The bad things about them:

Okay, time for the bad news. As wonderful as all of that sounded, there are some problems when it comes to many of the damsels. In fact, many of the commonly offered species should be avoided by reef aquarists altogether. (Keep in mind this doesn’t mean these same undesirable species aren’t perfectly fine in non-reef aquariums stocked with larger/more aggressive fishes that can take care of themselves, though.)

Anyway, some damsels may be very colourful when they are small, but lose

By James W. Fatherree, M.Sc.All images © James W. Fatherree, M.Sc.

Damselfish A L o o k a t t h e . . .

Chrysiptera parasema, the yellow tail damsel:

Mostly blue with a bright yellow tail, these are a little smaller than the blue devils and are far less aggressive. That doesn’t mean they’re necessarily peaceful though, and for a fish with a maximum size of about 2.5 inches, some individuals can be surprisingly obnoxious. Still, these are a far better choice than a blue devil, and most times they don’t cause any troubles, so I recommend them.

Chrysiptera hemicyanea, the

azure damsel:

This species also reaches about 2.5 inches, and looks a lot like a yellow tail with some extra yellow. The tail and the whole belly is bright yellow, with the rest being that same blue colour as the two previous species. These are some of my personal favourites, as they tend to be even less aggressive than the yellow tails, although I have had a couple over the years that had poor attitudes though. Still, I like them enough to recommend them.

Chrysiptera talboti, the talboti or Talbot’s damsel:

This one also reaches about 2.5 inches, but doesn’t look at all like the three above. No blue body on this one, but they still have attractive colours on their body, with a black spot on their back. Very pretty, and quite possibly the most peaceful of all the damsels. This species is highly recommended due to its generally peaceful nature, small size, and hardiness.

Dascyllus aruanus, the three-stripe damsel:

It is odd to me that with all the colourful marine fishes out there, some that are only black and white are still neat looking enough to bring home. The three-stripe is a good example, as its look is nothing more than 3 broad black and white stripes on a body that doesn’t get more than about 2.5 inches long. Unfortunately, they not only lack colour, but they generally lack any tolerance for other fishes, too. Yes, they can be pretty mean.

Dascyllus melanurus, the four-stripe damsel:

This one is very similar to the three-stripe damsel in both appearance and attitude. They get just a little bigger, maybe reaching about 3 inches, and they have a black tail rather than a white/clear one, but that’s about it. Mean again.

Dascyllus trimaculatus, the domino

or three-spot damsel:

These will fool you for sure. They’re seen for sale everywhere and look like cute little dominos when young, but they can also be very aggressive. What’s worse is that they lose the spots, turn a kind of crummy black, and get up to 4 inches long.

Neoglyphidodon oxyodon, the neon-velvet damsel:

Same for this one, but worse. When young, this species has cool looking neon blue racing stripes on its black body, but they lose these and turn completely black as they age, and can get up to about 6 inches in length. These are also exceptionally aggressive, even more so than the domino damsel, and I say should never be added to a reef tank.

Neoglyphidodon melas, the black

damsel:

Okay, I’m starting to sound like a broken record here. This species is also beautiful when small, but turns solid black and reaches up to 7 inches in length. And of course, they can be mean.

Chromis cyanea, the blue chromis:

Another schooler, which can be kept singly if you like, these can also be kept in groups and are generally peaceful. This species can reach a maximum of about 6 inches in length though, so they may get a little bigger than you would want. Still, if you don’t mind the size, these are a much better choice than the blue devil damsel if you’re looking for something blue.

Chromis viridis, the blue-green chromis:

Finally, we get to something else that I can recommend. The blue-green chromis is a nice colour, only gets up to about 3 inches maximum, can be kept in groups, and won’t bother each other or any other sorts of fishes either. Nice. On top of that, they also like to hang around near the top of aquariums, rather than constantly hovering close to and moving about the rockwork. This species is great for larger/deeper tanks, as a small school of them can really add to the overall look, instead of having a lot of less-traveled or even empty space at the top.

Microspathodoon chrysurus, the Atlantic jewel

damsel:

Same, again, except that these will loose all of their bright spots and grow to about 8 inches in length. Mean, mean, mean. Big ones will even take a nip at divers that get too close, which I’ve experienced myself.

Close:

All right, that’s enough to give you a pretty good idea of what the bunch is like, and in case you didn’t notice, I only recommended a handful out of these spe-cies for reef aquariums. Of course, there are so many species that I can’t cover even a significant percentage of them here, but you’ve got the basic idea now.

So, it’s up to you to do some homework if you want to try any of these or the oth-ers, and I suggest taking a look at:

Fish Base (www.fishbase.org) and/or Wet Web Media (www.wetwebmedia.com) before making any purchases. On these sites you’ll able to find some specific in-formation about damselfishes’ maximum sizes, habitat, and diets, etc. to help you make informed decisions.