During periods of drought or cold, they retreat into their shells and secrete a membrane (the epiphragm) of mucus and lime that covers the opening of the shell and resists desiccation.
Common garden experiments showed that gaping (periodic closure and opening of the shell) and attachment to the substratum differed significantly between the two lineages.
In each species, the males defend territories and hold harems of two to five females for whom they bury shells in a way that only the opening of the shell remains accessible to a resident female [ 14].
During emersion, they either close their valves and undergo anaerobic metabolism, or exhibit alternate closure and opening of the shell (gaping), allowing the maintenance of aerobic respiration [ 31, 32].
As before, push the hair into the opening of the shell and out through the shell's back.
The tip of the dreadlock should once more be positioned over the front opening of the shell in the same manner and placement as before.
