Author: Eigenmann, 1912
Comments: Rather rare (7 to 8 specimens known) maybe due to the very specialized biotope in which <i>Heptapterus longior</i> might be present.  It is therefore poorly identified, also considering that the original description, rather poor, identifies it only in comparison with <i>H. longior</i> starting from the size of the adipose fin and the more pointed caudal fin (Ref. 35381).