As you may have learned from a recent journal, the piranha is not the most feared fish of the Amazon region. It will not attack people unless it is cornered, hungry, and blood is present in the water. The fish most feared by the local residents is a tiny catfish, no more than two inches long called the candiru. This fish is normally a parasite on the gills of other fish but it also has the unfortunate habit of entering human orifaces. Since it has sharp spines that can firmly anchor it in the ears, nose, and urethra, surgery is required to remove the candiru.
Many catfish are carnivores or scavengers but the candiru is a parasite.
It attaches itself in the gills of bigger fish and sucks the blood of the host. Once satisfied, it releases its hold and swims out through the mouth. It uses the spines at the end of its tiny body to prevent it from slipping or moving backwards. As we travel to Iquitos and pass large tributaries, we lose water and now, as we approach Leticia Columbia, we are on water equivalent to 5 Mississipi rivers. The amount of water that flows out of the Amazon each day is the same amount of water that flow through the Orinoco river each year.