Detritivores, also known as detritophages or detritus feeders or
detritus eaters or saprophages, are heterotrophs that obtain
nutrients by consuming detritus (decomposing plant and animal
parts as well as organic fecal matter). By doing so, they
contribute to decomposition and the nutrient cycles. They should
be distinguished from other decomposers, such as many species of
bacteria, fungi and protists, which are unable to ingest
discrete lumps of matter, but instead live by absorbing and
metabolizing on a molecular scale. However, the terms
detritivore and decomposer are often used interchangeably.
Typical detritivorous animals include millipedes, woodlice, dung
flies, slugs, many terrestrial worms, sea stars, sea cucumbers,
fiddler crabs, and some sedentary polychaetes such as
amphitrites (Amphitritinae, worms of the family Terebellidae)
and other terebellids. Scavengers are typically not thought to
be detritivores, as they generally eat large quantities of
organic matter, but both detritivores and scavenger