Golden pencilfish

The golden pencilfish can be observed in the Brazilian Amazon and in Guyana and French Guiana, where it prefers a temperature of between 24 and 26 degrees Celsius and a pH between 5.5 and 7.0. The pencilfish therefore normally lives in acidic water. That acidification stems from the decomposition of plant matter, which explains this water’s tendency to grow very dark (like brewed tea), almost black when there is really a lot of organic matter.

This little fish can be found near the banks of waterways as well as in slow-moving streams and rivers, and in the standing water of small river offshoots. It likes shallow water (less than 50 centimeters) where a lot of vegetation can be found: aquatic plants, branches, a floor of dead leaves, and decomposing plant matter.