Two new species of Euryhaliotrema Kritsky et Boeger, 2002 (Monogenea: Dactylogyridae) from Lutjanus russellii (Bleeker) and L. argentimaculatus (Forsskål) (Teleostei: Lutjanidae) in the South China Sea.

Euryhaliotrema russellum sp. n. and Euryhaliotrema tenuiaccessorium sp. n. are described from the gills of Lutjanus russellii (Bleeker) and L. argentimaculatus (Forsskål), respectively, in the South China Sea. Euryhaliotrema russellum sp. n. differs from all other members of Euryhaliotrema Kritsky et Boeger, 2002 by its unique male copulatory organ, a straight tube with a bulbous base and without an accessory piece. Euryhaliotrema tenuiaccessorium sp. n. differs from its congeners by having a copulatory organ with a bulbous base, a meandering copulatory tube with clockwise coil having less than one complete ring, and a slender accessory piece along the middle length of the copulatory tube. All species of Euryhaliotrema are listed and divided to three groups based on morpholgy of the male copulatory organ.