Epulopiscium fishelsoni

Epulopiscium fishelsoni
Scientific classification
Kingdom:	Bacteria
Phylum:	Firmicutes
Class:	Clostridia
Order:	Clostridiales
Genus:	Epulopiscium
Species:	E. fishelsoni
Binomial name
Epulopiscium fishelsoni Montgomery & Pollak 1988

Epulopiscium fishelsoni, or "epulo" for short, is a species of Gram-positive bacteria that have a symbiotic relationship with surgeonfish. These bacteria are best known for their large size, ranging from 200–700 μm in length. Until the discovery of Thiomargarita namibiensis in 1999, these were the largest bacteria known. The bacterium has not been grown in the lab, but scientists have gained a better understanding of it through microscopic analysis.

Epulopiscium means "banquet of fish" in scientific Latin, from ("feast" or "banquet") and ("of fish"), as the organism was found inside the gut of fish.

The specific epithet fishelsoni is named for Lev Fishelson, a Polish-born Israeli ichthyologist who was part of the group that made the discovery while studying the intestines of a brown surgeonfish from the Red Sea in 1985. It was not named until 1988, by Montgomery (one of the co-discoverers) and Pollak.

They were initially classified as protists on the basis of their large size, until rRNA analysis by Angert, et al. in 1993 confirmed that Epulopiscium spp. are bacteria. Their research and studies illustrated the symbiotic relationship between the host surgeonfish.

Epulopiscium is one of the largest known bacteria, a million times bigger than Escherichia coli or Bacillus subtilis. It is large enough to be seen with the naked eye at 600 µm. However, because it is so big, it must compensate for its surface-to-volume ratio, regardless of its nutrient-rich environment. It also has special coping mechanisms and structures within it, which were originally thought to be organelles. These structures form a cortex within Epulopiscium that are made of vesicles, capsules, and tubules that excrete and transport waste throughout the cell.

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Wikipedia