This species is distinguished from Barryichthys hutchinsi by having a longer, narrower body (body depth at dorsal-fin origin 7-8% SL vs. 10-11% SL); more slender head (head width at widest point 55-61% vs. 66-75% HL); depth at orbit 27-29% vs. 30-32% HL; interorbital width 20-24% vs. 27-33% HL; the ventral margin of orbit visible in ventral view (vs. obscured by cheek); longer abdominal region with more vertebrae (21 vs. 17) and more ribs (15 vs. 11-12), epicentrals (18-19 vs. 14-15) and total vertebrae (42-44 vs. 38-39). Live colour pattern, including body background colour green (vs. golden yellow to olive-brown), no darker markings along dorsal midline or body side (vs. dorsal midline and lateral body side with darker markings) (Ref. 120657).