Parasaurolophus
Fish Fanatic
I was at maidenhead aquatics in st.albans earlier and one tank had a tetra labeled Rio negro tetra, it was with red finned tetras, I looked it up on the Internet and could find nothing it looks like a black neon tetra but larger and a cloudy black on it tail fin and lower half off the body, they had 5 of them but 1 looked very sick and wasn't shoaling with the others. Any information on this ''Rio negro tetra'' would be helpful, thanks! 
