According to Mago-Leccia , this was the biggest Serrasalmus that had been caught in Venezuela so far . Surinam and lower course of the Amozon . Members of this subgenus usually have a concave outline to the head and body . There are 37-38 teeth on the ventral keel . An aggressive species , widely distributed .
Juvenile fish show silvery speckles and the fins are light incolor and transparent like glass .
Adult specimens grow very dark , in some cases completely black , and shape of the body also alters . The body is strongly compressed laterally , and the snout shows a deep cleft . In profile the head is markedly concave . The platine bones are covered with a totally of 14 small teeth . A high-backet , compressed species .