January 2006 Palmetto Perspective
by Dianne Faucette, Master Naturalist
hundreds of whelk egg cases washed up on the beach in Palmetto
Dunes. Most people who donít study sea life think this unusual
debris is seaweed.
Mother whelks lay
egg strings along the South Carolina coast twice a year, in
April-May and September-October, depending on the water temperature.
The mother takes about a week to make a string which contains from
100 to 150 capsules. A string could be as much as 40Ē long.
Specialized glands secrete a substance that encloses usually 20 to
40 eggs in each capsule. She then buries one end of the string in
the sand under shallow water, and the rest of the string floats
while the baby whelks slowly develop over the next three to 13
months into perfectly formed whelk shells. The first ones to hatch
eat their unhatched siblings.
The strings of egg
cases break loose in turbulent water. By the time we see them washed
up on the beach, there are usually holes in each capsule which
indicate the eggs have successfully hatched. Occasionally some of
the eggs do not hatch, in which case an observer will see the
perfectly-formed almost microscopic whelk shells left in the
capsules. A whelk is one of the sea creatures that lives in one
shell for life, secreting the substance that continues the shell