Distinguished from all other species of the genus Harttia except Harttia tuna and Harttia trombetensis by having an incomplete abdominal cover, restricted to preanal and abdominal lateral plates with a row of platelets joining these two series of plates (vs. absence of row of platelets making junction between preanal and lateral abdominal plates), and by its specific barcode sequence (JF292263). Differs from Harttia tuna by having a deeper head (37.31-43.30, mean 38.94 ± 1.42% of HL, vs 31.96-38.77, mean 36.52 ± 1.80% of HL), and from Harttia trombetensis by its color pattern of caudal fin (a large dark band at base of caudal fin vs. a dark rounded blotch). Can be further diagnosed from all other congeners by having a greater minimum caudal peduncle depth (mean = 1.60 ± 0.11% of SL vs. 1.35 ± 0.13 < mean < 1.43 ±0.11% of SL); and a greater interorbital width (mean = 24.25 ±1.02% of HL vs. 22.04 ± 1.27 < mean < 23.12 ± 1.11% of HL) (Ref. 90209).