It may be necessary to distinguish between detritivores and saprotrophs based on the fact the former ingest and digest dead organic matter internally, while the latter absorb nutrients through external chemical and biological processes, see https://www.differencebetween.com/difference-between-detritivores-and-vs-saprotrophs/

A decomposer which obtains nutrition by consuming detritus.

There is some debate over whether detritivores should be considered a subclass of decomposers, see https://en.wikipedia.org/wiki/Decomposer. We welcome input on our issue tracker: https://github.com/nleguillarme/soil_food_web_ontology