With the ilish population declining day by day in Bangladesh’s rivers, researchers in Bangladesh have been trying to farm the national fish of the country in four phases.
 
However, their research has only proved that farming ilish commercially in ponds is not yet a viable option.

The government has also been keen to see such attempts succeed as ilish accounts for 1% of the country’s gross domestic product (GDP) and 11% of the country’s overall fisheries production.

https://www.dhakatribune.com/bangladesh/2020/10/14/commercial-ilish-farming-not-a-viable-option