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

Abstract

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.

Preliminary assessment of large‐scale co‐culture of sandfish (Holothuria scabra) with the Babylon snail (Babylonia areolata) in earthen ponds and in raceways

“…3 (RIA3) at Van Ninh, Khanh Hoa Province, Vietnam, which also provided the sandfish and Babylonia juveniles used in the study. Water and sediment analyses were conducted by the RIA3 Centre for Monitoring of Aquaculture Environment and Diseases, Nha Trang, Vietnam, using methods described by Dobson, Duy, and Southgate (2020). All data analyses were performed using the statistical software jamovi (Fox & Weisberg, 2018; R Core Team, 2018; Singmann, 2018; The jamovi project, 2019).…”

“…Sandfish were not directly fed. Separation of sandfish and Babylonia within the co‐culture ponds, rather than a free‐ranging culture system used in prior research (Dobson, Duy, Paul, et al, 2020; Dobson, Duy, & Southgate, 2020), was chosen to minimize potential negative effects on sandfish performance that could have resulted from daily Babylonia culture operations (i.e., collection of uneaten food).…”

“…The objective of Experiment 2 was to compare the culture performance of sandfish and Babylonia in co‐culture in concrete raceways, which provide larger scale than used in prior research at this facility (Dobson, Duy, Paul, et al, 2020; Dobson, Duy, & Southgate, 2020), but under more controlled culture conditions than were possible in Experiment 1.…”

“…A healthy substrate is therefore very important for maintaining hygienic conditions in culture ponds and sandfish may provide a means of assisting this. In initial assessments of the potential of sandfish/ Babylonia co‐culture systems, Dobson, Duy, Paul, and Southgate (2020) and Dobson, Duy, and Southgate (2020)demonstrated potential benefits to juvenile sandfish growth and improvements in water and sediment quality. Dobson, Duy, Paul, et al (2020) reported no negative impacts to sandfish growth in co‐culture with Babylonia , compared to sandfish monoculture, while a follow‐up study also reported that sandfish growth was, on average, 37.5% greater when co‐cultured with Babylonia compared to that in monoculture (Dobson, Duy, & Southgate, 2020).…”

“…In initial assessments of the potential of sandfish/ Babylonia co‐culture systems, Dobson, Duy, Paul, and Southgate (2020) and Dobson, Duy, and Southgate (2020)demonstrated potential benefits to juvenile sandfish growth and improvements in water and sediment quality. Dobson, Duy, Paul, et al (2020) reported no negative impacts to sandfish growth in co‐culture with Babylonia , compared to sandfish monoculture, while a follow‐up study also reported that sandfish growth was, on average, 37.5% greater when co‐cultured with Babylonia compared to that in monoculture (Dobson, Duy, & Southgate, 2020). Although these studies showed positive effects on sandfish growth in co‐culture systems, they did not specifically examine the effect of co‐culture on Babylonia growth and yield, nor did they assess the potential benefits of co‐culture to improve water and sediment quality compared with Babylonia monoculture.…”