Baby catfish are called sac fry & subsist for 5 days on this, even after they hatch from the egg
[DOC] [TLE] Apr - Pennsylvania Fish and Boat Commission [PAR] Page 5 ... in order* to provide fishing, the trout are retained at the hatoheries until 
they are ... for this type of fish cultural work, which takes in the collection of the 
eggs, .... black bass, yellow perch, catfish, sunfish, and shiner, a species of 
minnow.