The head of the dojô is small, the mouth is surrounded by six or eight barbules as is the case with several species of fish which inhabit muddy streams. … A microscopic examination showed them [the barbules] to be rich in muscular fibres for movement, and through the centre run a thick bundle of very delicate nerve fibres which spread out on the surface of each barbule's tip. These, I suppose from the manner which the dojô dips its head down, assist in the search for food, …