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Why do horseshoe crabs often spawn during high spring tides?
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horseshoe crab
Horseshoe crab (Limulus polyphemus).
Horseshoe crabs spawn during high spring tides in the spring and summer months to facilitate the placement of their eggs in the sand at the high-water mark. By utilizing these exceptionally high tides, the crabs can reach the upper portions of the beach to deposit their eggs in small, excavated depressions.12
This timing is critical for their reproductive cycle, as it ensures the eggs are positioned safely just below the high-tide line, where they can be fertilized externally by males. Once the spawning process is complete, the adults return to the ocean, leaving the eggs to develop in the intertidal zone.12