Have you seen this? In Melanau dialect it called PIPUS. Its my favorite food and I never miss buying this if go travelling. It only can be found in Mukah. According to reliable source pipus easily can be found during monsoon season. The rational behind this was, in monsoon season fishermen were not able to go to the sea and they have to depend with pipus as their food.
They normally will smoke the fish and punch it into smaller pieces before wrap it with sago leaf. Then they will continue to smoke it again so that they can keep it for longer period. Pipus is a good partner of beer.....