About how many soft-shelled turtle hatchlings are there in two jin?

This depends on the size of the soft-shelled turtle hatchlings. If they are slightly larger hatchlings, two jin would be about 4-5 of them; if they are smaller hatchlings, two jin would be about 10-15 of them. Specifically, the number in two jin still needs to be determined according to the size of the soft-shelled turtle hatchlings.

1. What are the costs and profits of raising 3000 soft-shelled turtles?

1. 1 mu of water surface can raise 300-400 soft-shelled turtles. After two years of rearing, 1 mu of fish pond can produce 600-800 jin of commercial soft-shelled turtles. For every 1 jin a soft-shelled turtle grows, it needs 5 jin of yellow mealworms or maggots. If you raise them yourself, the cost of 5 jin of yellow mealworms or maggots is about 6-8 yuan. Calculated at 7 yuan, the rearing cost for 1 soft-shelled turtle of 2 jin is about 15 yuan.

2. At present, soft-shelled turtle hatchlings on the market are 10 yuan each (if self-bred and self-raised, the cost per turtle is less than 1 yuan). The lowest market price of soft-shelled turtles is 60 yuan/jin. The net profit of 1 soft-shelled turtle weighing 2 jin is: 2 jin×60 yuan/jin-15 yuan (rearing cost)-10 yuan=95 yuan.

3. Raising 3000 soft-shelled turtles in 10 mu can earn a net profit of 280,000 yuan. The annual net profit is about 140,000 yuan. A soft-shelled turtle pond is the same as a fish pond. The cost of building a pond varies from place to place. Building a pond with cement is about 3000 yuan per mu (it can be used for decades). The construction cost of a 10 mu soft-shelled turtle pond is about 30,000 yuan. The cost of raising 3000 soft-shelled turtle hatchlings in a 10 mu fish pond is 30,000 yuan. The total investment in the first year of raising soft-shelled turtles in 10 mu is about 60,000 yuan (30,000 yuan for the 10 mu fish pond + 30,000 yuan for 3000 soft-shelled turtles). Since yellow mealworms and maggots are raised by yourself and are not a one-time investment, they can be ignored. An initial investment of 60,000 yuan is enough.