Chiang Mai Journal of Science

Platybaetis, Mller-Liebenau, 1980 and Baetiella (Gose, 1980) are baetid mayfly nymphs of the family Baetidae. This study reports the first discovery of Platybaetis bishopi Mller-Liebenau, 1980 and Baetiella bispinosa (Gose, 1980) in Thailand, with re-examination and illustration based on the P. bishopi Mller-Liebenau, 1980 nymphs from Narathiwat province. This study’s purpose is to revise the key characteristics of, specifically, the seven Platybaetis Mller-Liebenau, 1980 species currently found. Additionally, Baetiella bispinosa (Gose, 1980) nymphs from Chiang Rai province have been recorded for the first time in this region.