Question: how big do mud crabs grow?
Answer: The mud crab species Scylla serrata can grow up to 300 millimetres in shell width and 2.5 kilograms. The species Scylla olivacea can grow up to 150 millimetres in shell width and 1.5 kilograms. Known for their big claws, mud crabs belong to a group of crabs that have the last pair of legs flattened for swimming.