A review of the effects of environmental stress on embryonic development within intertidal gastropod egg masses

Gastropod egg masses are often deposited in the intertidal zone, where they are exposed to variable and often stressful environmental conditions that may affect the encapsulated embryonic development and survival of offspring. The present paper reviews data on developmental variation in gastropod egg masses owing to temperature, salinity, ultraviolet radiation (UVR) and oxygen availability. In general, increases in temperature or oxygen availability accelerate development, whereas UVR or extremes of salinity and temperature slow development and/or increase embryonic mortality. The relationships among these factors are discussed, as are their interactions with biotic factors, such as fouling, embryonic position within the egg mass and predation. One purpose of the present review is to raise awareness of these interactions so they become a focus for future research. Protective mechanisms of egg masses against environmental stresses are also reviewed. M a astm R. P la Additional keywords: mollusc, oxygen availability, reproduction, salinity, temperature, ultraviolet radiation.