Chlorococcum amblystomatis

Chlorococcum amblystomatis, synonym Oophila amblystomatis, commonly known as chlamydomonad algae or salamander algae, is a species of single-celled green algae. When placed in the genus Oophila, it was the only species. The Latin specific name amblystomatis means "loves salamander eggs". It does not occur anywhere in nature other than in the eggs of the spotted salamander, Ambystoma maculatum. The algae can invade and grow in the amphibian's egg capsule. Once inside, it metabolizes the carbon dioxide produced by the embryo and provides it with oxygen and sugar as a result of photosynthesis. This is an example of symbiosis, and the only known example of an intracellular endosymbiont microbe in vertebrates.

This symbiosis between Chlorococcum amblystomatis and the salamander may exist beyond the oocyte and early embryonic stage. Chlorophyll autofluorescence observation and ribosomal DNA analysis suggest that this algal species has invaded embryonic salamander tissues and cells during development and may even be transmitted to the next generation.

Chlorococcum amblystomatis are only found in freshwater in woodland ponds. They grow best at a water depth of 30 cm with the water temperature being 15 C and an air temperature of 14 C. Their optimal pH tolerance ranges from 6.26 to 6.46 and they require an environment where there is 12 hours of sunlight and 12 hours of darkness. Cells are motile: they are able to move the water by the use of a flagellum. Oophila amblystomatis can reproduce sexually and asexually. 16S rRNA has been partially sequenced as well as the 18S rRNA for the plasmid, however whole genome sequencing has not been done.