Acanthopoma annectens is a species of catfish (order Siluriformes) of the family Trichomycteridae, and the only species of the genus Acanthopoma.^[2] This fish grows to about 12 centimetres (4.7 in) SL. It originates from the upper and middle Amazon River, and is known to occur in Brazil, Colombia, Ecuador, and Peru.^[3] This species is parasitic, attacking like a leech and leaving wounds all over the fish which it attacks; it spreads a bundle of opercular and inter-opercular spines into the wound and remains there and is difficult to remove. It may invade parts of wading or swimming animals but apparently exist in these passages only for a short while, as they quickly die from a lack of oxygen.^[3]