Assessing potential to improve sandfish (Holothuria scabra) culture in Vietnam using supplemental seaweed feeding

Abstract

This study assessed potential improvement of sandfish (Holothuria scabra) culture using supplemental feeding with seaweed to explore its potential to support short-cropping. Three phased experiments evaluated juvenile growth and survival performance by: offering two types of seaweed-based supplemental feeds (Sargassum sp. and Gracilaria verrucosa) both processed by fermentation and pulverisation (Experiment 1); evaluating three stocking densities (25, 35 and 45 individuals per m2) using the best-performing diet from Experiment 1 (Experiment 2); and upscaling to commercial-level culture in three 400 m2 earthen ponds (Experiment 3). Fermented diets were prepared using a probiotic mixture (Saccharomyces boulardii, Lactobacillus acidophilus and Bacillus subtilis) added to ground, dried seaweed; while the pulverised diets were offered as a ground powder (350–450 µm particle sizes). Sandfish offered fermented Sargassum and Gracilaria reached 35.0% and 29.7% heavier mean final weights (18.18 ± 0.19 g and 16.81 ± 0.08 g, respectively), compared to their pulverised equivalents (11.82 ± 1.09 g across both seaweed species, p 0.05). Valuable new information has been generated for further development of supplemental feeding of sandfish, and results here demonstrate high technical feasibility to support short cropping, with optimisation of this culture model required.

Keywords

• Sea cucumber
• Supplemental feeding
• Seaweed
• Short-cropping
• Vietnam