I’ve had my soft coral reef now for quite a while. In October this year it will have its 6th birthday. Everything is fine, corals show good growth, there is some beautiful encrusting algae (I’ve just got a new bit which looks like multiple snowflakes stuck together – where did that come from?) and the fish are healthy and happy.
There used to be three fish but one, a flashback dottyback (Pseudochromis diadema) disappeared and I have no idea why. This occurred about 18 months ago. The remaining two are a blue damsel (Chrysiptera cyanea) and a flame angel (Centropyge loriculus). They both show wonderful colour.
The flame angel is the boss of the aquarium and always has been. Presumably the fish sees the aquarium as its territory. It acts perfectly normally until feeding time arrives. This isn’t any feeding time though; it’s the evening one, the time when the normal basic diet of marine flake is provided. Both fish eat well without dispute and always eat their fill. I have to be careful as I feel sure they would both eat to excess and then semi-digested food would pass into the aquarium – not wanted.
After feeding in the evening, the blue damsel goes to its favourite haunt which is mid-water at the right hand end of the aquarium. The flame angel however starts its antics. It doesn’t threaten the blue damsel but cruises up and down the front glass seemingly shouting ‘Look at me!’
With all fins stiffly extended it moves slowly along and it could hardly do anything else but move slowly. Making itself as big as possible it bobs a little upwards and then a little downward. Clearly it’s displaying and I have always assumed it would be to its own reflection in the glass. However, I moved to the end of the aquarium and the angel followed. I moved back and it didn’t. So I waited until it had got to the other end again and went to the opposite side – the angel followed. All of a sudden the fins went in and the fish became normal again, swimming much more efficiently around the aquarium. The damsel popped out, the angel gave a quick chase, and then all was peace and normality.
So what was that all about? As said the fish was clearly displaying but was it to me? My movements seemed to indicate it was, but maybe it was all coincidental. It does its display regularly after feeding in the evening but this is the first time it has reacted to my movements. I’ll have to try it again.
I remember a good number of years ago with a different aquarium there was a bit of fun at cleaning time, that is, when the magnetic scrubber went in to remove algae from the glass. At the time the aquarium contained a regal tang (which was a gorgeous blue and had been resident for a good while. When the magnetic cleaner appeared the fish would swim stiffly up to it and zigzag back and forth with fins erect. Obviously the magnetic cleaner didn’t take any notice! As the cleaner moved back and forth the fish would follow it, totally oblivious to the presence of my hand. The fish seemed to become more and more enraged and changed colour – the blue faded and it became much more of a pale blue/white. Clearly this was a territorial display and it only happened at cleaning time. The colour of the cleaner was blue so this strange square fish was an interloper into the territory, maybe seen as another tang of the same type.
The flame angel maybe sees the reflection in the glass and interprets it as an interloper. The movement outside (me) maybe connects with that and it follows.
If that is correct the fish is just boosting its street cred!