Analysis of the Polyculture Model of the Bivalves Anadara broughtonii and Chlamys farreri in Suspension Cages in Shallow Seas

This study examined the survival rates of Anadara broughtonii and Chlamys farreri with varying heights throughout winter and summer aquaculture periods under varying ratios of mixed-culture conditions in marine environments. The aim was to assess the viability and economic advantages of mixed-culture practices among different bivalve species. Results indicate that the winter (from December to February of the following year) mortality rate for A. broughtonii in mixed culture ranges from 12.04% to 16.85%, markedly lower than in single-species cultures. Mixed-culture A. broughtonii measuring 2.5–4.0 cm exhibit a significantly reduced summer (from July to September) mortality rate compared to those in single-species cultures (p < 0.05). No significant mortality difference was observed between the monoculture and polyculture of C. farreri. Growth rates of C. farreri and A. broughtonii showed no significant differences between monoculture and polyculture conditions. The optimal size for combining two different species of bivalves is 2.5 cm, with a 1:1 ratio being the most effective. An equal number of seedlings were cultivated across various seawater aquaculture systems for a period of one year. The survival rates of monoculture seedlings of Anadara broughtonii and Chlamys farreri were 60.34% and 86.55%, respectively. In contrast, polyculture seedlings exhibited higher survival rates after one year of mariculture, with Anadara broughtonii at 73.36% and Chlamys farreri at 89.74%. The polyculture of A. broughtonii and C. farreri in suspension cages demonstrates a favorable input–output ratio of 1:2.02. This approach effectively reduces winter and summer mortality rates of A. broughtonii, representing an efficient new method for marine bivalve aquaculture.