Culturing delicacies: Potential to integrate the gastropod Babylonia areolata into pond cultures of Caulerpa lentillifera

Abstract

In Van Phong Bay, Viet Nam, the economically important macroalgae sea grapes (Caulerpa lentillifera; Caulerpaceae, Bryopsidales) and the spotted babylon snail (Babylonia areolata) are cultivated in tidal ponds in close proximity. A co-culture in the same pond could benefit farmers by saving space and mitigating potential eutrophication. The study assessed the co-culture potential of sea grapes and spotted babylon snails held within the same system. In an outdoor experiment, three different treatments (algae and snails together, algae and snails spatially separated, only algae) were assessed for their effect on water quality, biomass properties and size increase of both organisms, photosynthetic efficiency, antioxidant activity, and total phenolic content of the macroalgae and survival of the snails. In a second (indoor) experiment, the influence of different snail densities on the physiological state of the macroalgae was investigated. In both experiments, the presence of the snails raised the concentrations of nitrogen oxides (NOx) and phosphate (PO4). The co-culture had a positive effect on both growth and physiology of the sea grapes. Sea grapes on trays and co-cultured with Babylonia showed the highest increase in biomass. Babylonia growth and survival were not affected by spatial separation of the alga and high stocking densities could be implemented without negatively affecting the seaweed. The results are promising regarding the establishment of co-cultures and indicate the economic feasibility of integrating B. areolata snails into C. lentillifera pond cultures.