With over 2000 species from which to choose, only a very small selection can be described here. Other species to look out for are Pimelodus pictus (Angelic Pirn), often sold as a community aquarium catfish, with a striking silvery body and black markings. This South American naked catfish grows to about 14 cm (5 1/2 in), and is fairly active during the day. Adult specimens may eat very small fishes, but juveniles are usually harmless. They can, like many catfishes, be extremely difficult to handle owing to their sharply pointed dorsal and pectoral fin spines. If these puncture your skin the mucus of the fish can cause mild blood poisoning, which can be quite painful for an hour or two.