Isolated from water samples collected at a depth of 20 cm below the water surface at the Johor Strait in the vicinity of Pulau Ubin island (Singapore, 1 deg 25 min 17.7 sec N 103 deg 57 min 20.6 sec E) and Johor river estuary (where the Johor river mixes with the seawater from the Singapore Strait and South China Sea).