I have a school of 4 or 5 Yoyo loaches – botanical name “Botia almorhae” also known as the Pakistani loach. I bought them a couple of years ago to eat the snail invasion I had in one of my tanks when I bought some new plants. Lately they have become strange. I have seen one of two of them stick their heads out of the water for a couple of seconds then go back into the tank, swim around and then do it again. My first thought, I checked the water quality and there is no problems there. The fish don’t seem stressed, no red gills, they don’t hide in caves, and they spend their days chasing each other round the tank. So I am curious to know why stick their heads out of the water, they do it in the corner the water comes back into the tank from the trickle filter so they are swimming in a water column. I was waiting to see a Clown Loach join in on the fun; I know they can be strange, like laying on their sides or head pretending their dead.