My pair of bala sharks have begun to exhibit bizarre behavior. They will follow one another around the tank, turn in opposite directions so that their tails are against each other, and rub the back quarters of their bodies against each other. Whenever any other fish in the tank swims by while they are doing this, one or the other of them will violently go after that fish until it is driven away. Then they will go back to this behavior.
They do this 90% of the time when not feeding. When they aren't behaving like this, they are wandering around the tank together taking turns attacking each other. It looks brutal, but so far there doesn't seem to be any damage, and most of the time the struck fish doesn't even run away (although they will on rare occasions). This behavior seems to be instigated more often by the slightly smaller fish.
Any ideas? Have my fish merely gone insane? They have behaved quite normally for over a year, so I am concerned about this sudden change.
Any help would be appreciated.
They do this 90% of the time when not feeding. When they aren't behaving like this, they are wandering around the tank together taking turns attacking each other. It looks brutal, but so far there doesn't seem to be any damage, and most of the time the struck fish doesn't even run away (although they will on rare occasions). This behavior seems to be instigated more often by the slightly smaller fish.
Any ideas? Have my fish merely gone insane? They have behaved quite normally for over a year, so I am concerned about this sudden change.
Any help would be appreciated.
