Australian freshwater lobster culture technology (Part 1)

??
?
Breeding experiments show that the survival temperature range of red crayfish is 5～35℃, and the suitable growth temperature is 13～28℃. When the water temperature exceeds 1 milligram / liters. They can also survive for a long time in humid and slightly watery conditions. During the breeding or overwintering process, red claw crayfish are often found on the embankments. Red-clawed crayfish are omnivorous animals. Under natural conditions, they mainly feed on organic matter detritus, algae, filamentous algae, roots, leaves and fragments of aquatic plants. They especially like juicy and tender green plants, such as water lily, water hyacinth, spinach, green duckweed and Vallisneria. There is no definite breeding season for red crayfish. When the water temperature is between 20～30℃, they can breed all year round and spawn multiple times. During the molting period, the shrimp is most vulnerable to predators or conspecifics, which is a dangerous period for the shrimp to die. (二)Artificial breeding?
1.Selection of broodstock?
?
Adult shrimp grown in earthen ponds must be soaked in formalin with a concentration of 200×10-6? for about 10 minutes before entering the overwintering pond. After the attached organisms are eliminated, they can be moved to the broodstock pond for cultivation. ?
?
Since broodstock are prone to burrowing during the overwintering period in earthen ponds, the best way to prevent this is to add water to the slope of the pond and use plastic film around the embankment to block an escape wall with a height of 30 centimeters. ?
Nutrients are the material basis for the gonad development of broodstock. In addition to placing a small amount of aquatic plants ( such as water hyacinth ) in the pond, commercially available shrimp and crab pellet feed with higher protein content is generally fed during early cultivation. ?
?
Red-clawed crayfish can generally lay eggs 2～3 times a year. The breeding period is 5～10 months, and the peak period is 6～Spawning and hatching of red crayfish?
The shrimps grown in the same year can reach sexual maturity after being raised and intensively cultivated during the winter. Generally, the weight of female shrimps is 50～70 grams, and the weight of male shrimps is 70～100 grams. ?
Female shrimps are inactive during the hatching period and are usually hidden in shelters. A small number of egg-bearing female shrimps are still feeding. Egg-bearing shrimp consumes a large amount of oxygen and must be continuously oxygenated during the incubation period to ensure that the dissolved oxygen is above 5mg/ liters. Control at 26～28℃. During the embryonic development of fertilized eggs, the egg color changes from yellow-green to dark red. Later, the transparent area gradually expands, the egg ball is slightly enlarged and elongated, eyespots appear, appendages form, and finally the egg membrane falls off and juvenile shrimp is formed.