Understanding damsels: chromis, clowns, and others

Understanding damsels, chromis, clowns...
These are the professional 'little guys' of the reef.
They require much more space than people realize: 100 gallons is good...for most.
They're also good 'dither fish,' who reassure other fish the coast is clear.

You can see dozens of them about a reef. Let a predator swim by and---boink!---if you blinked you missed it. They've all vanished.

WHere? Each fish individually has a tiny hole somewhere in the corals. No room for two. There's an ideal spot that's 'home', and it'll go there. It'll stay there til the predator shadow passes. They're also in that hole at night.

The size and type of refuge is closely dependent on species. And these fish don't usually share. It's THEIR hole, and they'll kill any fish that keeps trying to take it over. Who's likeliest to try? One of their own species, same size, same fit. This is a life and death thing: this involves safety. They can't be shoved out to be eaten. So if you have a small tank with minimal 'holes', you'll find damsels of the same species or of close size requirements getting ripped up and eventually disappearing.

Big enough tank, everybody's got a home, everybody's cool.

Clowns happen to do this hiding-number in anemones, and change sex to pair up. This is why they're so popular. You can't go wrong mating them.

I say---MOST are small fish. I've seen a domino damsel the size of a dinner plate. And clowns can reach five inches---that's saucer sized. The red clowns get that big. Clarkiis nearly. These have teeth, quite visible teeth, and bite, I'm here to tell you. The smaller clowns are ok in a smaller tank, and the chromises and the azure and yellow tail damsels can go in a 50 just fine. I recommend 1 damsel of a kind in a 50---they don't like to be crowded up---but they adjust quite handily. The little clowns are ok in anything that makes their nem happy: that's kind of their permanent hidey hole.

Damsels up and politicking with each other convinces everybody on the reef that it's safe to come out.

If you HAVE the right tank, and want fish to school up and swim---well, damsels won't quite do it, but you won't notice that much---because they herd one another into motion, so there's a constant game of bumper cars going on, a streamer of fish going round and round your reef. Because they pick mostly on their own rivals, and nobody gets nipped much except if you've got too little room for them to hide in, they're color, motion, and a lotta fish for a little money (except for the orange Garabaldis, which are another whale-sized damsel anyway.) THey don't eat corals, they don't bother other species, and they're easy keepers. They're healthy fish, come in many colors and patterns (like angelfish, they sometimes change color and pattern as they grow, so look at what the adult looks like to be sure that suits you.) They're really compatible with just about everybody, blennies, gobies, tangs, angels, and whatever: they don't bother anybody but their own species.

Just be sure you have plenty of hiding spots (branching coral is a favorite) and that you've got a good variety of types.

Of all the tanks I've had, I think my damsel-100 was my hands-down favorite.