The freshwater shrimp Caridina gracilipes is widely distributed in the Indo-Pacific, and both landlocked and amphidromous populations occur in southern Taiwan. In this study, we collected monthly samples between September 2006 and August 2008 from a lake and a stream, representing landlocked and amphidromous populations, respectively. We found the amphidromous individuals were larger and grew faster than the landlocked individuals. The mature females in the landlocked population are in general small compared to the amphidromous population, and their eggs were larger but fewer than the amphidromous females. Ovigerous females could be found year-round in both populations, but the main recruitment was in September. The life span of females was longer than males; that of amphidromous were longer than landlocked populations. We found that populations of C. gracilipes in the subtropical region have evolved different biological and reproductive strategies based on their landlocked and amphidromous life histories.