Fifty one families and 323 species of fish were discovered at Dongsha Atoll in 2004 during a survey by scuba-diving. Among them, 71 species were not recorded by Chen et al. (1995), boosting the official record of the fish species in the area to 467. Among the new findings, two new species, Ctenogobiops sp. and Xenisthmus sp. are currently being named. Nine other species: Callogobius hastatus, C. maculipinnis, Ctenogobiops feroculus, Eviota nigriventris, Apogon thermalis, Acreichthys tomentosus, Doryrhamphus melanopleura, Canthigaster epilampra, Himantura fai and Scarus fuscocaudalis were not officially recorded in Taiwan, although the last three species could be found. After the occurrence of massive coral breaching in 1998, the greater number of fish species were found outside the atoll, followed by stations adjacent to Dongsha Island, and the least number were found at stations inside the lagoon.