Epigonus marisrubri is distinguished from its congeners by the following combination of characters: dorsal-fin rays VII + I,10; anal-fin rays II,9; pectoral-fin rays 18; pored lateral line scales 48 or 49; gill-rakers 10+19-20; pyloric caeca 10; vertebrae 10 + 15; 2 pterygiophores between neural spines 9 and 10; pectoral fins long, reaching level of second dorsal-fin origin; caudal fin forked; tongue with a band of 2-4 rows of densely-set teeth on glossohyal; opercle with short, poorly ossified spine and 1-2 small spinelets; otolith oval, elongate, sulcus and cristae weakly developed (Ref. 83754).