Hydrurus foetidus
{{Short description|Species of alga}}
{{Speciesbox
| image = Hydrurus foetidus.jpg
| image_alt = Scientific drawing of a single tetrahedral spore on the left and multiple cells growing within a thallus on the right.
| image_caption = Tetrahedral spore (left) and cells growing in a thallus (right) of Hydrurus foetidus published circa 1885
| genus = Hydrurus
| species = foetidus
| authority = (Villars) Trevisan
}}
Hydrurus foetidus is a large freshwater alga found in a cold rivers.{{Cite journal |last=Klaveness |first=Dag |date=2019-03-15 |title=Hydrurus foetidus (Chrysophyceae): an update and request for observations |url=https://www.e-algae.org/journal/view.php?doi=10.4490/algae.2019.34.1.15 |journal=Algae |language=English |volume=34 |issue=1 |pages=1–5 |doi=10.4490/algae.2019.34.1.15 |issn=1226-2617|hdl=10852/73314 |hdl-access=free }} It is a member of the chrysophytes, or golden algae.
Distribution
H. foetidus is found in cold, fast flowing rivers typically during times of snowmelt. It is found globally north of 40° N and south of 40° S. It has been reported in South and North America, Russia, Japan, the Himalayas and in Hope Bay, Antarctica.