Osmotic induction of stress proteins in nemerteans

Nemerteans can experience fluctuating salinity during exposure to low tides in intertidal mudflats. This study attempted to determine if stress proteins (SPs) can be induced in nemerteans exposed to fluctuating salinities under laboratory conditions. Paranemertes peregrina Coe 1901 were collected from intertidal mudflats. The ribbon worms were then acclimated at 34‰ for 3–4 days prior to the salinity stress experiments. For the hyperosmotic experiment, 39 and 44‰ were selected. Salinities of 24 and 29‰ were used for the hyposmotic experiment. Both experiments used 34‰ as the control. Three worms were sampled at 0, 2, 4, 6, 12, 18 and 24 h after incubation at each of the salinities. Weights were recorded before and after the sampling periods to determine water efflux and influx under hyperosmotic and hyposmotic conditions, respectively. SPs detected in the nemertean proteins were separated by SDS–PAGE electrophoresis and identified using Western immunoblots with specific antibodies. SP levels were then qua...