Certain fish will breed in captivity like dottybacks, damsels, clowns, cardinals but you’ll only ever see the eggs and getting pairs other than clowns can be hard. Raising these fish would have to be done in a separate tank and you’d need plenty of small live foods of varying sizes to feed the fry.
20 Gallon SPS reef
29 Gallon FW "fat catfish" tank
20 Gallon Long Dart Frogs "Zig" and "Zag"