Comments on restricted distribution of Mytilopsis adamsi Morrison, 1946, a non-native false mussel in the Songkhla Lagoon System, southern Thailand

The establishment of Mytilopsis adamsi Morrison, 1946 populations in areas around the mouth of the Songkhla Lagoon System, southern Thailand, was first reported in 2008. A recent survey has revealed they now have a wider distribution range. However, this distribution is surprisingly restricted to only within a number of the rivers running into the lower part of the Thale Sap Songkhla Lake, the southernmost part of the system. Moreover, these populations were not found within the lake itself. Effects of the fluctuation in salinity and the local dynamics of water current within the system on the mussels’ ability to disperse as possible causes of restricted distribution are discussed.