Neopterygii is a subclass of Actinopterygii (ray finned fish) who do not possess electro-perception (ability to perceive electrical stimuli), nor the organs (Ampullae of Lorenzini) to detect electrical impulses in the water. Their name translates as new fins.
Based on evolutionary studies the Neopterygii (new fins) appeared somewhere in the Late Permian, before the time of the dinosaurs. There are only few changes during their evolution from the earlier actinopterygians. They are a very successful group of fishes, because they can move more rapidly than their ancestors. Their scales and skeletons began to lighten during their evolution, and their jaws became more powerful and efficient. Unlike other groups of fish, hagfish aside, Neoptergii have lost their ability to perceive electrical impulses in the water though the Neopterygii known as catfishes retain (or re-evolved) a limited ability to sense electrical impulses in water. An ability granted by their whiskers which are nonhomologous teleost ampullae.