Suitability of Betaphycus gelatinus for future domestication

Betaphycus gelatinus is a red seaweed with emerging commercial interest due to its potential as a source of high-quality carrageenan and bioactive compounds. Despite its promise, there remains a lack of established cultivation techniques for this species. Here, we provided a comprehensive assessment of the strain-specific performance of B. gelatinus grown in land-based cultivation systems, focusing on growth and its seasonality, morphological transformation, and a snapshot biochemical analysis at the end of a one-year cultivation period. Three B. gelatinus strains, namely KU9-PGD, KG1-PGD, and K-PGD, were collected from field and maintained in a land-based culture system. Significant differences in growth rates were observed among strains, with generally higher values recorded during the inter- and southwest monsoon (0.78 – 3.09, 1.74 – 4.41, and 1.79 – 5.45% d −1 , respectively) compared to northeast monsoon (0.49 – 1.44, 1.25 – 2.12, and 1.20 – 3.97% d −1 , respectively). Among the three strains, K-PGD exhibited the most robust growth, underscoring the importance of strain selection in optimizing biomass yield. Growth rates also varied between cultivation systems, with glass aquaria (1.30 – 2.87% d −1 ) promoting higher growth rates than concrete tanks (1.15 – 1.75% d −1 ). The domestication of B . gelatinus resulted in morphological transformation where changes in branching, pigmentation, and thallus surface features emerged compared to their respective original wild forms. During the southwest monsoon sampling, biochemical profiles (pigments, carbohydrates, proteins) of the three strains remained relatively uniform under controlled conditions. These results affirm the potential of B. gelatinus as a viable crop for future commercial mariculture and provide valuable baseline information for developing cultivation protocols and selecting high-performing strains for large-scale production.