Cirrhinus microlepis is a freshwater medium-sized carp that can be naturally found in large and medium-sized rivers and lowland floodplains of Chao Phraya and Mekong basins in Thailand, Laos, Cambodia, and Vietnam. It is one of the most important fish species for those regional fisheries. Besides increased fishing, the factors that have probably contributed to an overall decline of natural populations of C. microlepis over the years are hydrological and hydraulic changes, habitat degradation, water pollution, loss of habitat connectivity, climate change, increasing land use for crops, and introduction of alien fishes for aquacultural purposes. This has stimulated the development of aquaculture of this species. Even the fish weights and lengths for several individuals are decreasing at some places, like Tonle Sap lake in Cambodia. It is now considered a vulnerable species in the IUCN Red List. Because most wild information about C. microlepis is missing, it is difficult to know its natural needs and behaviours that are important to evaluate its welfare state under farming conditions. Even farm information is scarce about this species, and most of what is known is about carps in general. Further research is urgently needed to better assess and improve the welfare of C. microlepis.
