Distinguished from its congeners by the presence of a horizontally elongated dark spot on the caudal peduncle, and by the absence of any other dark pigmentation pattern on the body. Differs from H. immaculatus, another species without dark pigmentation on the body, by having 25-27 epibranchial and 36-37 ceratobranchial gill rakers on the first branchial arch, and caudal-fin lobes without longitudinal stripes (Ref. 53268).