Before coming to Sri Lanka, we in Singapore its common to eat huge Sri Lankan mud crab, so, was anticipating to find them everywhere but could not find even one and they don't know what a Sri Lankan mud crab is. Finally we saw it here in the Madu River, a mangrove swamp like river. Bought 2 of them from these kids each about 1 1/2 kilo for 2400 Sri Lankan rupees which is S$24. We had to kill them ourselves as they being budhists will not kill the crabs. Delicious.