Last week I discussed some of the distinguishing features of and cool facts about the Lightning Whelk, Sinistrofulgur sinistrum (Hollister, 1958). Today I want to explore certain aspects of the reproduction in this celebrated species. As with most of the large, predatory marine snails, Lightning Whelks have separate sexes, and females lay eggs inside protective egg capsules. Each egg capsule may contain a few dozen eggs, and capsules are attached to each other through a string—one string may connect as many as a couple hundred capsules. Mother Lightning Whelk starts the egg-laying process by attaching the first section of the string under the sand; string and capsules are manufactured by a special gland under the mother’s foot (photo on left). After a couple of months of confined (but protected) development, the young whelks leave via an “escape hatch” near the edge of each capsule.
The Lightning Whelk, Sinistrofulgur sinistrum. From left: Female Lightning Whelk attempting to lay egg capsules on an aquarium wall; arrow points to capsule-making gland on bottom of foot (photo by José H. Leal); string of egg capsules, at Kice Island, Collier County (photo by Anne Dupont).