Probarbus labeamajor
Three species have been described within the genus: Probarbus jullieni, Probarbus labeamajor and Probarbus labeaminor (Roberts 1992). All three are included in the IUCN List of Endangered Animals, the first as "Endangered", and the latter two as "Data deficient". In addition, Probarbus jullieni is listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), Appendix I.
Probarbus jullieni and Probarbus labeamajor appear to have very similar migratory habits, and although fishermen at many places can distinguish between the two species (e.g., they have different local names), they are reported to migrate together. A third species Probarbus labeaminor ?) was reported at Sungkom district, Nong Khai province (Thailand) with similar migratory habits to Probarbus jullieni and Probarbus labeamajor. Since the two first species appear to be very similar with respect to migratory habits, they are considered together in this publication.
The two species occur throughout the survey area, from the Mekong delta to the border between the Lao PDR, Thailand and Myanmar. As with most of the other migrating species covered by the current survey, the migrations of Probarbus can be divided into spawning migrations and trophic migrations Upstream spawning migrations occur between October and February from Kompong Cham (Cambodia) to the north-ernmost station of Chiang Khong (Thailand). Above the Khone Falls, the main spawning period was eported to be January to February, sometimes extending into March-April. At Chiang Khong, fishermen reported that Probarbus migrated up the Nam Ta tributary in the Lao PDR to spawn during March-April. A spawning site was described.