While at the fish shop yesterday, I noticed that a baby lionhead was nipping the tail of a baby black moor over and over again. The moor had its dorsal fin and anal fins clamped down - is this due to stress?
It is a horrible thing to watch and when I asked the assistant about it he said it was bullying as opposed to the nipping fish being hungry. Then I noticed a telescopic fish doing the same to a baby ranchu, who also looked ailing. Is there anything that can be done to put a stop to tail nipping? Do nippers tend to target unwell fish who are easy prey, and if so, how does the fish sense that the ill fish is unwell? Does nipping permenantly injure the victim fish?
The moor had its dorsal fin and anal fins clamped down - is this due to stress?
yes the fish is not very happy and stress can be shown in this way. fin nipping is sometimes down to bullying but with bubble eyed type fish it could be because they can not see very clear and if something floats past their eyes they think it is food and try to eat it, if a fish is not well the other fish can try to chase it away so the fittest survive.
When it's 'feeding time' in my tank sometimes i see a bit of tail nipping to get to the food first - they never seem to do any damage but in the tank at work if a fish is ill they all turn on it i think it's like survival of the fittest and they don't want to live with a sick fish
its worse than that, they will actually eat the fish, its just they sense a weakness they will all pick on the fish, the fish gets more and more overcomed and stressed, eventually due to stress, diesease will set in the fish get a free meal, esp where fish of diffent sizes are kept, also there is less competition for the food you feed,if there is one less mouth. Its just the law of nature and not much we can do other than to minimise it as much as possible, you always get one tank bully, just like in the playground, the others may try and keep out of its way. The bigger the tank the less chance of it, the bully cant be everywhere at once so spread the food out as much as poss, also hiding places and well planted tanks will hinder bullys. I had a very bad one, that actually started to bite of bits of the other fishes.
We had a 'cannibalism' problem in the works tropical tank -when we first set it up, it was terrible. The tank had been cycled for a month and water tested, i think we added to many at once and some got sick
I had a bully - my favourite Comet Jeremy, he was the smallest fish i had but charged the others when he felt like it and headbutted them poor jeremy