stercomata

Stercomata are produced by members of several different subclades of Foraminifera that possess organic-walled or agglutinated tests, including: single-chambered taxa with spherical organic-walled tests (e.g., Bathyallogromia and other undescribed species),{{cite journal |last1=Gooday |first1=A. J. |last2=Holzmann |first2=M. |last3=Guiard |first3=J. |last4=Cornelius |first4=N. |last5=Pawlowski |first5=J. |title=new monothalamous foraminiferan from 1000 to 6300m water depth in the Weddell Sea: morphological and molecular characterisation |journal=Deep Sea Research Part II: Topical Studies in Oceanography |date=2004 |volume=51 |issue=14–16 |page=1611 |doi=10.1016/j.dsr2.2004.06.025 |bibcode=2004DSRII..51.1603G |url=http://www.sciencedirect.com/science/article/pii/S0967064504001468|url-access=subscription }} single-chambered taxa with sac-like agglutinated tests (e.g., Saccammina and Leptammina),{{cite journal |last1=Cedhagen |first1=T. A. |last2=Gooday |first2=A. J. |last3=Pawlowski |first3=J. |title=A new genus and two new species of saccamminid foraminiferans (Protista, Rhizaria) from the deep Southern Ocean |journal=Zootaxa |date=2009 |volume=2096 |issue=1 |page=15 |doi=10.11646/zootaxa.2096.1.3 |s2cid=15080995 |url=https://www.biotaxa.org/Zootaxa/article/view/zootaxa.2096.1.3|doi-access=free }} single-chambered taxa with tubular agglutinated tests (e.g., Bathysiphon),{{cite journal |last1=Gooday |first1=A. J. |last2=Pond |first2=D. W. |last3=Bowser |first3=S. S. |title=Ecology and nutrition of the large agglutinated foraminiferan Bathysiphon capillare in the bathyal NE Atlantic: distribution within the sediment profile and lipid biomarker composition |journal=Marine Ecology Progress Series |date=2002 |volume=245 |page=69 |doi=10.3354/meps245069 |bibcode=2002MEPS..245...69G |url=https://www.int-res.com/abstracts/meps/v245/p69-82/|doi-access=free }} multi-chambered taxa with organic-walled tests (e.g., Nodellum and Resigella),{{cite journal |last1=Gooday |first1=A. J. |last2=Kamenskaya |first2=O. E. |last3=Kitazato |first3=H. |title=The enigmatic, deep‐sea, organic‐walled genera Chitinosiphon, Nodellum and Resigella (Protista, Foraminifera): A taxonomic re‐evaluation |journal=Systematics and Biodiversity |date=2008 |volume=6 |issue=3 |page=390 |doi=10.1017/S1477200008002776 |s2cid=86134857 |url=https://www.tandfonline.com/doi/abs/10.1017/S1477200008002776?journalCode=tsab20|url-access=subscription }} taxa with complex agglutinated tests composed of delicate branching tubes (Komokioidea),{{cite journal |last1=Tendal |first1=Ø. S. |last2=Hessler |first2=R. R. |title=An introduction to the biology and systematics of Komokiacea (Textulariina, Foraminiferida) |journal=Galathea Report |date=1977 |volume=14 |page=171 |url=https://www.researchgate.net/publication/268274172}} and deep-sea taxa with large, complex tests agglutinated tests (Xenophyophorea).

In xenophyophores, the stercomata are contained within an organic tubes called stercomare.

Gromiida is a subclade of Endomyxa, a clade that branches within the more inclusive group Rhizaria, a clade that encompasses a diverse array free-living and parasitic single-celled eukaryotes that possess branching or anastomosing pseudopodia and complex life cycles.{{cite journal |last1=Krabberød |first1=A. K. |last2=Orr |first2=R. J. S. |last3=Bråte |first3=J. |last4=Kristensen |first4=T. |last5=Bjørklund |first5=K. R. |last6=Shalchian-Tabrizi |first6=K. |title=Single cell transcriptomics, mega-phylogeny and the genetic basis of morphological innovations in Rhizaria |journal=Molecular Biology and Evolution |date=2017 |volume=34 |issue=7 |page=1559 |doi=10.1093/molbev/msx075 |pmid=28333264 |pmc=5455982 |url=https://academic.oup.com/mbe/article/34/7/1557/3058782?login=false|doi-access=free }} {{cite journal |last1=Cavalier-Smith |first1=T. |last2=Chao |first2=E. E. |last3=Lewis |first3=R. |title=Multigene phylogeny and cell evolution of chromist infrakingdom Rhizaria: contrasting cell organisation of sister phyla Cercozoa and Retaria |journal=Protoplasma |date=2018 |volume=255 |issue=5 |page=1523 |doi=10.1007/s00709-018-1241-1 |pmid=29666938 |pmc=6133090 }}

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.{{cite journal |last1=Jepps |first1=M. W. |title=Contribution to the study of Gromia oviformis Dujardin |journal=Quarterly Journal of Microscopical Science |date=1926 |volume=s2-70 |issue=280 |page=701 |url=https://journals.biologists.com/jcs/article/s2-70/280/701/63157/Memoirs-Contribution-to-the-Study-of-Gromia}} {{cite journal |last1=Hedley |first1=R. H. |title=Gromia oviformis (Rhizopodea) from New Zealand with comments on the fossil Chitinozoa |journal=New Zealand Journal of Science |date=1962 |volume=5 |issue=2 |page=122}} {{cite journal |last1=Gooday |first1=A. J. |last2=Holzmann |first2=M. |last3=Majewski |first3=W. |last4=Pawlowski |first4=J. |title=New species of Gromia (Protista, Rhizaria) from South Georgia and the Falkland Islands |journal=Polar Biology |date=2022 |volume=45 |issue=4 |page=655 |doi=10.1007/s00300-022-03017-4 |s2cid=246790431 |url=https://link.springer.com/article/10.1007/s00300-022-03017-4|url-access=subscription }} Individual stercomes range in size from <5 μm (G. psammophila) to 15-30 μm (G. saoirsei). Stercomata consist of the undigested remains of ingested food and may include mineral grains, sponge spicules and diatoms, which are held together by glycosaminoglycans. {{cite journal |last1=Hedley |first1=R. H. |last2=Bertaud |first2=W. S. |title=Electron-microscopic observations of Gromia oviformis (Sarcodina) |journal=Journal of Protozoology |date=1962 |volume=9 |issue=1 |page=81 |doi=10.1111/j.1550-7408.1962.tb02585.x |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1550-7408.1962.tb02585.x|url-access=subscription }} Unlike the stercomata in foraminiferans, the stercomata in gromiids are retained in the cytoplasm and not stored outside of the cell body; however, after the release of flagellated gametes during sexual reproduction, the stercomata remain in the interior of the test.

• Feces
• Fecalith

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Category:Foraminifera