Stercomata (or stercomes) are extracellular pellets of waste material produced by some groups of foraminiferans, including xenophyophoreans and komokiaceans, Gromia, and testate amoebae.
[1] Stercomata are composed of small mineral grains and undigested waste products held together by strands of glycosaminoglycans.
[2] The term “sterkome” was first used Schaudinn in 1899 to describe the balls of undigested food remains produced by the testate amoeba Trichosphaerium sieboldi, the foraminiferan Saccammina sphaerica, and the gromiid Gromia dujardinii.
[9] [10] In Gromia, the only described genus of Gromiida, stercomata are spherical to ovoid in shape and range in color from brown to gray to orange.
[13] Stercomata consist of the undigested remains of ingested food and may include mineral grains, sponge spicules and diatoms, which are held together by glycosaminoglycans.