Do snails and hermit crabs contribute to the nitrogen cycle? Obviously fish do, and apparently cocktail shrimp do as well, but do hermit crabs and snails produce ammonia waste?
They do, but I think the efforts they make in converting wastes to something else out weigh the amount they contribute. As wetmanNY once said--a snail is much better at making detritus into more snail than at making detritus.