How do my Kuhli loaches..

[Makino]

...know when i put food in the tank?
Do they "smell" the food, or are they sensing the other excited fishes through the lateral line?
I'm just curious really. Never see them during the day, but the second food goes in they come out right on cue.

[wetmanNY]

Quite a few fishes have exterior taste buds, aside from the ones on their barbels. They are scattered on the fishes' heads, and I recall even along the lateral line to some extent (is that right?) It only takes a couple of molecules dissolved in the water to fire nerve endings. Our chemical senses of taste/smell are so dull by comparison, we can scarcely imagine a fishes' sensitivity.

Sensing other foshes' feeding reactions is a strong cue too. Part of what makes schooling behavior effective.