|MadSci Network: General Biology|
Dear Trina, According to a book I have (Little & Kitching, The Biology of Rocky Shores, Oxford University Press, 1996), the life span of one species of limpet, Patella vulgata, depends on how high on the rocks at the shore the limpets live. Those that live at the highest spots that get wet only during the high tide live longer (12-15 years) than those that live close to the water and are wet most of the time (4-5 years). The limpets release their eggs and sperm directly into the sea. Although my book doesn't give any numbers, I suspect that in cases like these, where the meeting between an egg and a sperm cell entirely depends on chance and when the mortality rates are very high, millions of eggs and sperm cells will be released. Only a very small fraction of these gametes will become larvae and a smaller fraction of the larvae will survive to become adults. Aydin Orstan
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