Rhizosomichthys totae
Photo: Wikimedia Commons (CC) via https://en.wikipedia.org/wiki/Rhizosomichthys
Overview
Rhizisomichthys is a monospecific genus of freshwater ray-finned fish belonging to the family Trichomycteridae, the pencil and parasitic catfishes. The only species in the genus is Rhizosomichthys totae, sometimes known in English as greasefish. This fish grew to about 13.8 centimetres (5.4 in) and was endemic to Colombia where it occurred in the Lake Tota basin.
It is listed as a critically endangered species by the IUCN Red List. The species was last seen in 1957, and only 10 specimens were found. The disappearance is possibly linked to the release of 100,000 imported rainbow trout eggs into Lake Tota in 1936.
Rhizosomichthys totae faces severe threats from habitat degradation in Colombia's Magdalena River basin, where agricultural expansion and urban development have dramatically altered its freshwater environment. Water pollution from agricultural runoff and industrial discharge has compromised water quality in its limited range. The species' extremely restricted distribution makes it particularly vulnerable to localized environmental changes, with dam construction and water extraction further fragmenting its already limited habitat.
Habitat
This freshwater fish is endemic to the Magdalena River basin in Colombia, inhabiting specific riverine environments with particular water chemistry and flow characteristics. It requires clean, well-oxygenated waters with specific substrate conditions typical of neotropical river systems.
Conservation measures underway
Other threatened species in TRICHOMYCTERIDAE
Threatened in Colombia
Frequently asked questions
Why is Rhizosomichthys totae classified as Critically Endangered?
Where does Rhizosomichthys totae live?
What are the main threats to Rhizosomichthys totae?
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