Raising sea crabs in 2 stages, 6 months to reach 0.4kg/crab, survival rate over 60%

HA TINH Raising sea crabs in 2 stages helps increase the survival rate. After more than 6 months of raising, the crabs reach an average weight of 0.4 kg/crab, the survival rate is over 60%, and the productivity is over 2 tons/ha.

Sea crab is a high - value aquatic species, adapting well to different salinities and diverse environmental conditions, so the farming technique is relatively simple. This is one of the key subjects for aquaculture development in the direction of diversification, both expanding the farming species and applying many farming methods to improve economic efficiency.

Two-stage crab farming helps minimize risks and brings stable profits to farmers. Photo: Anh Nguyet.

In Ha Tinh , in addition to natural exploitation, for many years, in areas of ineffective shrimp farming, people have raised sea crabs, but mainly in extensive farming, affected by the weather, so many limitations have been revealed such as low survival rate, low productivity, and low quality of commercial crabs.

Faced with this situation, from 2023 to 2024, the Ha Tinh Agricultural Extension Center deployed a two-phase crab farming model to adapt to climate change in Thach Khe and Co Dam communes. As a result, the model achieved and exceeded the set targets, and was highly appreciated by the industry and the people. To gradually replicate the model, in 2025, the Center continued to build a demonstration model in Hai Ninh ward.

The model was implemented at Mr. Truong Song Thao's household - a member of Bac Son Hai Aquaculture Cooperative, Hai Ninh Ward. The number of crabs released for breeding was 20,000 by raising in 2 phases. In phase 1, crabs with a size of 0.5 - 1cm were released at a density of 30 crabs/m2 in a nursery pond area of ​​700m2. After more than 1 month of raising, the crabs reached a size of 2 - 2.5cm, the survival rate was over 50% and were transferred to the commercial pond in phase 2 on an area of ​​10,000m2.

After more than 6 months of raising, the crabs developed well, reaching an average weight of 0.4 kg/crab, a survival rate of over 60%, and a yield of more than 2 tons/ha. Photo: Anh Nguyet.

During the entire farming process, Mr. Thao strictly followed the technical process of raising two-stage sea crabs according to the instructions of the technical staff of the Provincial Agricultural Extension Center. In the pond preparation stage, he renovated and treated the environment according to regulations, arranged nets around the shore, and created shelters to limit crabs from eating each other.

Crabs are raised in small ponds before being transferred to commercial ponds to help control the quality of the seed and increase the survival rate. During the rearing process, the owner strictly manages the water quality, periodically checks the salinity, pH, and temperature, and also feeds according to the "4 rules" - quality, quantity, time, and location.

The food is a combination of industrial food with a protein content of over 35% and fresh trash fish, ensuring nutrition, helping crabs grow quickly, have beautiful shiny shells, and firm meat. The model owner also regularly supplements minerals and multivitamins to increase the crabs' resistance and adaptability to weather changes, especially during prolonged hot periods.

Households participating in the model strictly followed the two-phase crab farming technical process according to the instructions of the Ha Tinh Agricultural Extension Center. Photo: Anh Nguyet.

Thanks to strict adherence to technical processes and pond environment management, crabs grow well, have a high survival rate, and bring about clear economic efficiency. After more than 6 months of farming, crabs reach an average weight of 0.4 kg/crab, a survival rate of over 60%, and a yield of over 2 tons/ha. With an average selling price of 300,000 VND/kg, after deducting costs, the model brings in a profit of about 370 million VND/ha.

Mr. Truong Song Thao excitedly said: “Previously, the shrimp farming area was no longer effective, my family switched to crab farming but in the form of extensive farming, without applying techniques, the breed depended on natural exploitation, the economic efficiency was very limited. When the Provincial Agricultural Extension Center introduced the 2-phase crab farming model, I registered to participate.”

According to the new process, management and care are more convenient. Crabs are raised before being released into commercial ponds, so they are uniform in size, adapt quickly to the environment and have good resistance to adverse weather conditions, helping to increase survival rate.

Two-stage farmed sea crabs have firm meat quality and little loss. Photo: Anh Nguyet.

According to Mr. Thao, previously, crabs were collected from the wild, so their sizes were not uniform, and they had to be released in many batches. During the process of raising the larger ones, they ate the smaller ones, so there was a lot of loss, the survival rate was only 30-40%, or even lower, and there were cases of total loss. Through applying the solution of raising crabs in two stages using artificial breeds, it has shown a high survival rate and a significant increase in output. Crabs raised in two stages have firm meat quality, and are less affected by diseases or adverse environmental conditions.

The model was supported by the Ha Tinh Agricultural Extension Center with a part of the breed, 50% of the cost of industrial feed, and technical guidance and supervision throughout the implementation process. Through the implementation of the model with training activities, tours, acceptance, summarization..., it has created opportunities for many people to access new technical processes and the benefits of applying the 2-phase crab farming technique.

Mr. Pham Danh Hiep, Vice Chairman of Hai Ninh Ward People's Committee, said that the ward has many favorable conditions to develop aquaculture with an area of ​​over 350 hectares. In the coming time, the government will focus on promoting and expanding the 2-phase crab farming model to stabilize the farming area and improve economic efficiency.

Source: https://nongnghiepmoitruong.vn/nuoi-cua-bien-2-giai-doan-6-thang-dat-04kg-con-ty-le-song-hon-60-d785110.html