What do ocean catfish eat?
A wide range of feeding behaviors and diets are represented by
the catfishes. In the family Trichomycteridae alone, there are
species that feed on algae, fish scales, mucus, carrion, insects,
or even blood in the infamous candirú. Panaque and some species of
Hypostomus are unique among catfishes in that are the only fishes
able to eat and digest wood.Members of the aspredinid genus
Amaralia are known to specialize in feeding on loricariid eggs.
Source: http://en.wikipedia.org/wiki/Catfish#Ecology