Danio concatenatus is distinguished from all other congeners except D. assamila, D. dangila, D. catenatus, and D. sysphigmatus by produced first ray in pectoral and pelvic fins, large cleithral spot, and pattern of dark rings enclosing light interspaces on the side. It differs from those species by having round cleithral spot (vs. vertically extended in D. dangila), presence (rarely absence) of anterior interstripe Ia (vs. absent in D. dangila, D. catenatus), round or slightly elongate rings in in two series along side, width of dark perimeter of about same width as diameter of light centre (vs. elongate in D. assamila and D. sysphigmatus, with narrower perimeter in D. sysphigmatus; three rows anteriorly in D. catenatus), ring pattern usually not extending onto caudal peduncle (vs. extending onto caudal peduncle in D. catenatus and variably in D. dangila), and 35-36 scales on lateral line (vs. 32-34 in D. dangila, 32-34, rarely 36 in D. assamila) (Ref. 101154).