Thermal Tolerance of the Shallow-Water Ostracod Cyprideis from a Lagoon in Bahrain, Western Arabian Gulf

Laboratory experiments were conducted to determine the thermal tolerance of the living ostracod Cyprideis sp. from a lagoon known as Murray’s Pool on the east coast of Bahrain, in the western Arabian Gulf. Our experimental trials, run in duplicate using a semi-controlled thermal incubator, demonstrate the resilience of the ostracod community to elevated temperatures. We observed that ostracod specimens begin to enter an inactive condition or become comatose at about 39.4 °C, and with increase in temperatures, half of the specimens died or did not recover at 51.8 °C. At 53.5 °C, total mortality is observed with no indication of recovery. These observations have implications for climate change predictions in the western Gulf region, as water temperatures in the lagoon reach 42 °C in summer, while the substrate temperatures on mud flats exposed during low tide exceed the lethal limit of the ostracods during the summer months.