The remaining 11 fishermen, who were appearing before a different magistrate, were not brought to court because the presiding magistrate was not feeling well.
They were further remanded to May 31 for sentence.
In passing judgment, Banda said cases of illegal entry into the neighboring country were on the rise and it was the duty of the court to punish those who were found in conflict with the law to deter would-be offenders.
On count one, the fishermen were charged with illegal entry into Zambia, while on count two, the 21 accused persons were charged with fishing without a license contrary to the Zambian laws.
The 10 convicts will serve 12-month effective jail terms after the court suspended the other 12 months on condition of good behavior.