. The Biological bulletin. Biology; Zoology; Marine biology. EMERGENCE OF LARVAL LIMULUS 497. 2130 0030 0330 TIME 0630 0815 Figure 1. Movement of larval nests to and away from the surface of the beach during nights of full moon (solid line) and new moon (dotted line). The arrow indicates the time of high tide in each case. Bars indicate 1 Movement of nests to the surface on the night of full moon was not repeated on the night of new moon. miii after the high tide. Usually, some 15 to 20 individual larvae become partially exposed at the surface, with the rest of the nest remaining immediat
. The Biological bulletin. Biology; Zoology; Marine biology. EMERGENCE OF LARVAL LIMULUS 497. 2130 0030 0330 TIME 0630 0815 Figure 1. Movement of larval nests to and away from the surface of the beach during nights of full moon (solid line) and new moon (dotted line). The arrow indicates the time of high tide in each case. Bars indicate 1 Movement of nests to the surface on the night of full moon was not repeated on the night of new moon. miii after the high tide. Usually, some 15 to 20 individual larvae become partially exposed at the surface, with the rest of the nest remaining immediately below the surface. Each wave washed away the surface animals and carried them down the beach into the water. Many were cast back up onto the beach and stranded as the tide receded, where they formed drift lines of larvae on the beach. Most of these animals remained at the surface until daylight, after which they disappeared, falling prey to shore birds at dawn. The willet, Catoptrophorus semipalmatus, was a major predator. Reburial was probably not of great signficance since scat- tered individuals were only occasionally found beneath the surface. Thus, larvae were seen to move in the field from their original burial depths to the surface and back down again over a 12 hr tidal cycle on the night of full moon. Such pro- nounced movements to the surface did not occur on the night of new moon. There was no significant difference between mean nest depth at low tide and mean nest depths at high tide on the night of new moon in 1979. The depths of nests at the hour of high tide on the subsequent neap tide, new moon spring tide and second neap tide of the lunar month in 1978 are presented in Figure 2. Only on the night of the full moon spring tide did larvae come to the surface. The water did not reach the level of the nests at any time other than during spring tides at full and new moon. The results of the plankton sampling adjacent to the breeding beach on day and night tides th
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectb, booksubjectzoology
