There are so many choices of fish for fish only and reef systems. Fish only systems usually carry a higher number of inmates and these could be just about anything available at the LFS (local fish shop), the restrictions being the size of the aquarium and the compatibility of the fish types. Reef systems usually carry a lower number of fish and these are often smaller species, so that seawater quality is more easily maintained and the fish generally are more easily accommodated.
So fine, I’m only going to be allowed one small fish. It doesn’t matter if it is a fish only or reef system, that’s the lot! Oh, dear, what now?
I have favourite fish of course. One of them is that interestingly shaped and beautifully marked butterflyfish, the copperband, properly called Chelmon rostratus. This fish though very attractive has a drawback – it’s a bit of a lottery with feeding some will, some won’t. My luck would be that the one I had would turn out to be a ‘won’t’.
Ah, here’s a real contender, one of the dwarf angelfish. These have been called ‘God’s gift to aquarists’. They are beautiful but do not reach the size of the ‘normal’ angels such as Pomacanthus species. Yes, the flame angel (Centropyge loriculus) is really a contender – it is reasonably hardy, has a strong character and can be quite bossy if given the chance, but this usually isn’t a problem and in this case it wouldn’t be anyway being the only fish. They are easy to feed.
What about that attractor to the marine hobby, the so-called ‘common’ clownfish properly named Amphiprion ocellaris. I would guess that this fish has been responsible for quite a few people getting into the hobby. It is hardy, easy to feed and undeniably attractive. There is one drawback though, the fish likes an anemone and I would like to give it one, though they’ll live without. Unfortunately the one only rule means this fish isn’t the one (unless I try to argue that an anemone is not a fish so I can have one!).
How about a damsel? These are well known hardy fish and I have always admired the Fijian blue damsel properly called Chrysiptera cyanea. They feed very easily. However, admire it as I do it is not as beautiful as some others.
Then again there are the dottybacks. They can be scrappy and only one to an aquarium unless it is very large, but there is only to be one. Hmm, what about the ’flashback’ dottyback, Pseudochromis diadema? They’re an eye catching yellow with a light purple/red flash on the back, easy to feed and hardy. Well, maybe.
It could be a real problem this choice of one fish, there are so many worthy contenders it could go on and on. But it won’t. I know what I’ll choose.
At the back of my mind throughout has been one fish. This fish is not rare and is easily obtainable. It is not expensive. It is quite happy to live alone and feeds easily on many standard foods, particularly liking brine shrimp. It is a very beautiful fish. So what is this wonder of the salty world?
It is the Royal gramma, properly called Gramma loreto. It has been a favourite small fish of mine for a very long time. To my eye it is stunning, and if lit by blue (actinic) lights really shows up. The way the front half of the body colour changes gradually to the rear half is so much ‘better’ and sophisticated than the instant change of the bicolour dottyback Pseudochromis paccaguellae. The only ‘drawback’ is that if the fish is in a cave it could on occasion be seen floating belly up, which the aquarist doesn’t want to see his/her fish do! However, this is a known trait in this fish and shouldn’t be anything to worry about.
So I’ve picked my fish and it’s the Royal gramma. I don’t think I would be disappointed with my choice under the circumstances.
Having said that I’m glad that this is only a ‘what if’ situation, I can have whatever fish I desire in real life with the usual imposed limits. Nevertheless, the Royal gramma must be one of the most beautiful and desirable small fish available. If seawater quality is maintained, there shouldn’t be a problem with these hardy fish which are so suitable for a reef aquarium.
Here’s some more text and pictures: