In the laboratory, groups of 4 to 5
crabs each were held for 2 to 7 days under a natural, light/dark (14 h
light: 10 h dark) photoperiod at 23–25 °C in 60-L plastic tanks
containing aerated spring water (b0.5‰ salinity, pH 6.09) to a depth
of approximately 10 cm, replaced two to three times per week.