**Abstract:**
The cultivation of Qinghai shrimp was conducted using the facilities originally designed for crab breeding. In 2001, a total of 220 million larvae were reared in a 200-hectare area, achieving an egg-holding rate of 93%, a hatching rate of 84%, and an average breeding rate of 33%. The average seedling density reached 163,000 individuals per cubic meter.
**Keywords:** Shrimp; nursery; egg-holding rate; hatching rate; cultivation rate
**CLC number:** S966.12+2.2 | **Document code:** B | **Article ID:** 1003-1721 (2002)02-0005-02
Green shrimp (*Macrobrachium nipponense*), also known as Japanese Macrobrachium, is a high-value crustacean species native to China. Due to overfishing, natural populations have declined significantly, leading to rising market prices and a growing demand. To address this, artificial breeding has become essential. The development of shrimp farming relies heavily on a stable supply of seedlings. In 2000, we initiated industrial-scale nursery trials using the existing crab breeding facility. By 2001, improvements in breeding techniques led to successful results, which are detailed below.
**1 Materials and Methods**
**1.1 Breeding Conditions**
The nursery is an artificial brackish water system originally built for crabs, including storage tanks, single-cell algae culture ponds, rotifer breeding areas, indoor nurseries, and broodstock holding pools. These facilities are housed within a 1000 m² greenhouse with glass roofs, equipped with large Roots blowers and heating systems. Water is sourced from Lake Plano (660 hectares).
**1.2 Broodstock Rearing**
A temporary holding pool (160 m², 1.5 m deep) was used to house the broodstock. Water was filtered through a 100-mesh sieve, and shelters like rocks and bamboo were added. Broodstock were selected from Dongting Lake, with specific size criteria: body length over 3 cm, tail weight above 4.2 g, or body length over 4 cm, tail weight over 5 g.
**1.3 Feeding and Management**
Broodstock were fed twice daily—8% of their body weight in the morning and afternoon, with adjustments based on consumption. Food included soybean meal, corn flour, small fish, snail meat, and cooked egg yolk. Water was changed weekly, and the pools were flushed daily for 1–2 hours to promote spawning behavior. Oxygen levels were maintained at 5 mg/L, and lime and antibiotics were used for disease prevention.
**1.4 Algae and Rotifer Cultivation**
Single-cell algae were cultured in 4 m² cement tanks, with nutrient concentrations adjusted over time. Rotifers were raised in separate ponds, using algae as a base feed. Freshwater copepods were collected and treated for use.
**1.5 Larval Rearing**
Nursery ponds (15 m², 1.5 m deep) were prepared with aeration stones and shaded covers. Larvae were transferred once they reached a density of 500,000 per m³. Feeding schedules varied by stage, with single-cell algae, soy milk, and later rotifers and snail meat.
**1.6 Water Quality and Disease Control**
Water quality was monitored four times daily, with dissolved oxygen maintained between 6–10 mg/L, pH 7.5–8.2, and low levels of ammonia and nitrite. Malachite green was used to prevent parasites, and oxytetracycline was applied every two days.
**2 Results**
Using 1,500 kg of broodstock (including 1,200 kg females), the egg-holding rate was 93%, with an average of 3,000 eggs per female. In 2001, 670 million larvae were hatched, with an 84% hatching rate. About 200 million seedlings were raised, achieving a 33% breeding rate, with a peak of 41%.
**3 Discussion**
While many studies have focused on small-scale breeding, this trial successfully utilized existing crab facilities for large-scale shrimp production. The method improved survival rates, reduced costs, and provided a new model for inland aquaculture. The use of shade cloth and controlled feeding enhanced larval activity and survival, making this approach highly promising for future shrimp farming.
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