Seven Vibrio strains (including V. vulnificus HM-TA-D2-L2-V2; V. vulnificus HM-TA-G2-V1-D2; V. brasiliensis HM-X-13/6; V. cholerae V-13/6; V. parahaemolyticus HM-17/6; V. cholerae HM-V-13/6 and V. vulnificus HM-X-13/6) causing hemorrhagic disease in red drum (S. ocellatus) had only the tlh gene, and none of the Vibrio strains had tdh and trh genes (Quang et al. 2020). Here, TDH is linked to hemorrhagic disease.