Growth rate
Value given is the maximum rate of increase in shell length observed in the first year of growth by Blackmore (1969). From the findings of many workers however, it is clear that growth fluctuates from year to year and from place to place to such an extent it is difficult to make general statements. Growth depends on temperature and is greatest in summer, least in winter. Growth also varies between microhabitats being greater under fucoids (17.1 mm per year) than on barnacles (14.7 mm per year) where locomotion and grazing are difficult. Growth rates and longevity are inversely related. Animals under fucoids grow rapidly and may live only 2-3 years whereas those on bare rock, with little food, grow slowly but may live 15-16 years. Limpets move about when the tide is in and the sea is not too rough. Animals are more active when submerged due to the lower energetic cost of moving on mucus when under water. Under thick fucoid covering or when conditions are damp, individuals may be found on the move after the tide has fallen.

The upper limit of distribution on a shore is increased by shade and exposure. In some situations seasonal variations in sunshine causes a downward migration in spring/summer and an upward migration in autumn/winter, though the upward movement is not confined to individuals which originally occupied the high levels (Lewis, 1954). Spat settle in pools and damp places, becoming vagrant after emergence for the first 1-3 years and then settle down to a homing lifestyle, although swapping of home does occur. Adult Patella vulgata generally return after feeding to their so-called 'home scar', a depression in the rock formed by abrasion of the rock surface by the shell, resulting in a tighter fit to the rock and reduced risk of desiccation. Patella vulgata is tolerant of low salinities extending into the mouth of estuaries, surviving in salinities down to about 20 psu (Fish & Fish, 1996).