Overwintering by trilobite larvae of the horseshoe crab Limulus polyphemus on a sandy beach of Delaware Bay (New Jersey, USA)

Trilobite larvae of the horseshoe crab Limulus or unusually heavy wave action.Within 2 additional polyphemus L. develop from eggs deposited within intertidal sediments.Most of these larvae emerge from sediments during the summer.We have found that a smaller component of the larval population on a Delaware Bay (New Jersey, USA) beach can delay emergence, and remain alive within the sediments until the following spring.Overwintering trilobites were distributed in a 3 m wide band in the mid-tide region, at sediment depths > 15cm.103 to 104 live trilobites