Yes fish food. That's how Shepard rolls. Why buy 3 kinds of food when you can buy just one?
Mass Effect Comic 'Collectable'
[Shepard bursts in on the collector leader's secret room]
Shepard: It's over, collector!
[The collector leader is revealed to be quite small]
Shepard: Your days of -
Shepard: You won't ... uh..
Shepard: You're tiny
Shepard: And adorable
[Shepard keeps the collector leader in a terrarium and feeds him fish food]
Shepard: Are you hungry Mr. Collector?