It is observed that the possible spawning dates in 2009 are about 10, 12,12, 1 1 or 10. The actual occurrence time depends on the rainy season, rainfall, migration location, soaking, mating, spawning, brooding and other times, and spawning is carried out in the first 4 weeks when these conditions are met. Everything depends on the weather.
The first batch of male red crabs that migrated to the breeding area began to mate with female red crabs. They have to keep soaking in seawater to replenish water in time. During this period, the male crabs could not resist the passion of a large number of female crabs and retreated to the lower terraces to dig caves. The density of caves is extremely high (there are 1-2 hidden caves per square meter. Females usually mate with males on the platform of caves dug by males. ) After the breeding season, the male moves quickly, reaches the plateau in 1-2 days, and starts to return to the mainland again.
Female insects lay eggs within 3 days after mating, and they are protected in terraced fields 12- 13 days. These crab eggs develop in wet caves, and the eggs are stored in the pouch between the swollen abdomen and chest of the mother crab. A female crab can lay 100000 eggs.
After about a month in the ocean, these seedlings survived after several growth stages and developed into animals called megalopa like shrimp. Megalobrama amblycephala larvae 1-2 days ago gathered on the shore and left the water as crab seedlings. Although the crab seedlings were only 5 mm, they began to cross and March inland, and reached the plateau about 9 days later. Then it seems to disappear, but it is rare to see it. In the first three years, they appeared on the forest floor, occasionally under rocks, fallen branches and debris. For many years, little or no crab seedlings have emerged from the sea, but occasionally a very successful year (maybe only one year, two years or ten years) is not enough to maintain a high level of red crab population.