Gnathodolus bidens is a species of headstander endemic to the Orinoco and Casiquiare rivers in Venezuela.

Gnathodolus bidens is known to be found in a freshwater environment within a benthopelagic depth range.

[1] Gnathodolus bidens can be found in South America, Orinoco, Casiquiare rivers, and Venezuela.

[1][2] Gnathodolus bidens has the ability to breed once the pair is in a heavily dense and weeded area.

[1] This species serves as no threat to humans and they are considered to be harmless.