Wood-eating Catfish Panaque are a distinctive group of armored freshwater fish native to the Amazon Basin and neighboring river systems. They stand out for a remarkable diet that centers on wood as a resource. In the wild they graze on submerged logs and biofilms made up of algae, microplants, and tiny organisms that cling to timber. The wood itself passes through the gut largely unchanged, while the microbial partners inside their digestive system extract nutrients from the biofilm. The catfish bear thick armor and a body shape that helps them maneuver through tangled wood and sediment. Their feeding behavior influences the structure of fallen timber habitats and contributes to nutrient cycling in tropical rivers. This lifestyle fosters a close relationship with floodplain ecosystems, where seasonal inundation creates new feeding grounds and shelter. Ecologists studying neotropical rivers note that Panaque species inhabit forested waterways, where their wood grazing supports a dynamic wood-based food web. The Amazon basin hosts a diverse range of Panaque species, each adapted to local wood types and water conditions. Citation: National Geographic.
Habitat conditions for the wood-eating catfish center on warm, oxygen-rich streams of the Amazon rainforest. They favor slow to moderate currents with abundant submerged wood, including fallen logs and snags that accumulate in backwaters and floodplain lagoons. During the annual floods they venture into newly flooded forests where standing water creates corridors for grazing and breeding. Their armored bodies and strong jaws enable steady scraping of timber surfaces, while nocturnal activity helps them avoid daytime predators. Citation: Smithsonian Tropical Research Institute.
DID YOU KNOW? – The wood-eating catfish eats wood but cannot digest it fully. It relies on the biofilms and tiny organisms that live on the timber to supply nutrients, while large wood fragments pass through as waste. This processing helps support the nutrient cycle across the stream ecosystem. Citation: National Geographic. – It has four jaws with teeth that can move in different directions to grind and scrape timber. Spoon-shaped teeth allow it to scour rough surfaces and detach the attached biofilm, enabling efficient grazing on logs and submerged timber. Citation: University of Florida IFAS. – Males develop bristles on their fins and heads during breeding periods, likely serving as signals to attract mates and define territory in murky waters. Citation: Tropical Fish Hobbyist. – In some local communities, whole fish are prepared and eaten directly, often after cooking the shell-like armor, reflecting regional culinary traditions. Citation: Local Culinary Archives. – The characteristic spoon-shaped teeth support scraping and accessing biofilms on fallen logs, enabling a steady grazing approach that favors wood-based feeding. Citation: Journal of Neotropical Fishes.