Why is this loach shadowing my bigger fish?
I have a Kubotai loach that continually pesters two of the larger fish in my 180cm/6ft community tank.
He swims close up alongside one of the adult Red rainbowfish and also the Siamese algae eater, virtually touching, and copying their movement so that if they turn, he turns with them and so on. This must be really annoying and they can’t seem to shake him off.
He doesn’t do it continually, but I see it happening most nights and it can go on for some time. He is one of a group of six other Kubotai loaches, so he has plenty of ‘friends’ of his own kind.
Is this anything you have come across before? Do you know why he’s doing it? KEV HYDE, EMAIL
NEALE SAYS: Botia species are a curious mix of sociability, belligerence and simple high spirits, and your Botia kubotai is no exception. In the wrong aquarium Botia can be troublesome, and the other fish in the tank may indeed find them annoying, even stressful. So, let’s review their basic needs and work from there.
As you know, these are social fish. Their social interactions are based as much on touch as anything else, and in groups you’ll see Botia doing exactly the same things with each other as you’ve seen between your Botia kubotai and its tankmates. Nuzzling, mock nibbling at fins, head-butts, tail swishes, and side-by-side swimming are all features of their behavioural repertoire, helping each loach in the group to establish the size and strength of its peers.
More subtle cues may be conveyed that we can’t easily determine, given that their bodies are covered in pressure receptors and taste buds, and it may well be they can figure out things like health, sex and maturity just by swimming closely alongside each other.
While six specimens usually provides enough for everyone to be happy, you should understand that in the wild they will be living in groups that may be much larger than that. So, if you can, adding a couple more specimens might reset the hierarchy, encouraging the lone loach to mix back into his group. Sometimes, removing the troublesome fish – in this case, all of the loaches – rejigging the decorations, and then returning the fish is another way to force the hierarchy to be rebuilt. The loaches don’t recognise their environment, so revert to schooling together as a defence mechanism. They then need to establish the pecking order and, with a bit of luck, a more amicable arrangement ensues.
Your Botia kubotai are river-dwelling fish, and appreciate a complex environment that includes brisk (though not turbulent) water currents, plenty of rocks and bogwood roots, and suitably
Botia species are a curious mix of sociability, belligerence and simple high spirits
soft substrate that allows them to dig. Without these things, their swimming and foraging instincts will be directed into less helpful expressions. What they don’t want is an open tank with coarse gravel and a few rocks or plants providing little cover or interest.
Bottom line, your Botia kubotai might need more friends, and he may need a more interesting world. If neither of these helps, either move the loaches to a tank tailored to their needs, or else move the fish being harassed somewhere more peaceful. Botia are rarely ‘easy’ community fish in the same way as, say, Corydoras, and finding tankmates that get along with them often involves a degree of trial and error.
Social issues may stem from group size or the environment.