Freshwater aquaculture in Thailand started a long time ago, but initially only a few species were raised, such as common carp (Cyprinus carpio), sepat siam (Trichogaster pectoralis) and striped catfish (Pangasius sutchi). Such cultures were operated solely on a small scale and were confined to the area around Bangkok. Until the middle of 1951, other species - i.e. Chinese carp (Ctenopharyngodon idellus), walking catfish (Clarias batrachus) and striped snakehead (Ophicephalus striatus) - were introduced and extensive fish culture extension programs were implemented. Within a short period of time, a large number of ponds were either constructed or converted from old ones for fish farming. Several idle swamps were converted and operated by farmers. From 1963 onwards, many valuable species rapidly developed, partially as a result of a breakthrough in artificial breeding by hormone injection. At present, more than 15 species of fish and invertebrates are cultured. According to the latest data available (1997), catches from freshwater culture amounted to 200 177 t, valued at 5 954 quantity and valued at 80 million Baht. Although 1997 output from this sub-sector in quantity and value contributed only about 5-6% to the country's total fish production, it reflects an increasing trend over the past two decades (1977-1997), averaging an annual increase of 10.7% and 15.7% in quantity and value, respectively.
