Other Fish
Bull Shark (Carcharhinus leucas) Florida Museum
https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/bull-shark/
While some Amazonian fish species deserve dedicated pages, a few are worth mentioning even if they don't warrant their own entries. Here are two unique fish that stand out for their unusual behaviors and ecological roles.
Bull Shark
The bull shark (Carcharhinus leucas) is a species of shark capable of surviving in both freshwater and saltwater. While they have a global distribution, they are only occasional visitors to the Amazon River. However, bull sharks have been documented as far as 2,400 miles (3,860 km) upstream, reaching Peru (Smithsonian Environmental Research Center).
Bull sharks are formidable predators known for their adaptability and aggressive nature. Despite their resilience, they are listed as Vulnerable by the International Union for Conservation of Nature (IUCN Red List) due to habitat loss and overfishing.
Candiru
The candiru (Vandellia cirrhosa) is a small parasitic catfish native to the Amazon. Measuring about an inch (2.5 cm) in length, it is known for its habit of attaching to the gills of larger fish and feeding on their blood (Breault, 1991; Britannica).
Despite its relatively minor role in the Amazon's ecosystem, the candiru has gained an infamous reputation due to persistent myths. According to popular folklore, the fish is attracted to urine and will swim up the urethra of anyone who urinates in the water. Some versions of the myth claim that the candiru will leap from the water, lay eggs inside its host, or require surgical removal. However, there is little to no scientific evidence supporting these claims, and they appear to be more urban legend than reality (Schulman, 2019).
References:
Bull Shark Species Profile Smithsonian Environmental Research Center
https://serc.si.edu/labs/fish-and-invertebrate-ecology/bull-shark-species-profile
Bull Shark IUCN Redlist
https://www.iucnredlist.org/species/39372/2910670
Breault, J. L. (November 1991) Canduri: Amazonian parasitic catfish Journal of Wilderness Medicine Volume 2 Issue 4 Pages 304-312
Candiru Britannica
https://www.britannica.com/animal/candiru
Schulman, Jill Seladi. (May 23, 2019) Is There Really a ‘Penis Fish’ That Swims up the Urethra? Healthline
https://www.healthline.com/health/penis-fish