First assessment of the potential for coculture of sandfish ( Holothuria scabra ) with Babylon snail ( Babylonia areolata ) in Vietnam

The potential for the coculture of sandfish, Holothuria scabra and Babylon snail, Babylonia areolata was investigated. Sandfish (weight 1.87 ± 0.41 g) were cultured at low (25 ind/m 2 ; 46.75 g/m 2 ), medium (50 ind/m 2 ; 93.5 g/m 2 ), and high (100 ind/m 2 ; 187 g/m 2 ) densities in monoculture and in coculture with Babylonia at a density of 400 ind/m 2 (208 g/m 2 ). In monoculture, sandfish were provided with 1 g m −2 day −1 commercial prawn starter feed. In coculture, trash fish provided for Babylonia (5% total wet weight per day) was the only food input. Sandfish survival over the 84‐day experiment period was reduced in coculture treatments (77.60 vs. 97.22%) but was in line with expected survival rates (80–90%) of commercial sandfish culture. Mean sandfish weight gain and absolute growth rate were around 37% greater in coculture (mean weight gain 13.42 ± 2.90 g vs. 9.77 ± 2.54 g over 84 days). No differences in Babylonia growth rate or survival were evident between sandfish density treatments. Sediment organic matter content did not differ significantly between monoculture (0.43 ± 0.03%) and coculture (0.55 ± 0.06%) treatments, but the latter had elevated concentrations of ammonia. Results provide a basis for further development of land‐based pond coculture systems for sandfish and Babylonia .