Latin, petra = stone + Greek, kephale = head (Ref. 45335).
Etymology of specific name :
Dedicated to Dr. John P. Friel, curator at the Cornell University Museum of Vertebrates, in recognition of his contribution to African ichthyology and for his care of the large collection of African electric fish deposited at CUMV; in addition John P. Friel is one of the collectors of this new species (Ref. 91772).