Twenty-one fishermen were sentenced to one year of rigorous imprisonment, while six other were fined for catching Illish illegally in Manikganj on Tuesday.
Besides, 20,000 metres of current net and 50 kilograms of Illish were seized.
Daulatpur Upazila Nirbahi Officer and Executive Magistrate Md Shafiur Rahman handed down the verdict while they were netting the fish from the Jamuna despite a ban on catching Illish.
The UNO did not jail six other fishermen, as the ages of the two of them were over 70 and the rest were under 16.
The elder fishermen were fined Tk10,000 each, while the other four Tk2,500 each.
The seized fish were donated to a local orphanage and the gillnet was burnt.