Evaluation of the morphological characteristics and culture performance of Cladosiphon okamuranus strains

This study aimed to determine whether morphological differences of Cladosiphon okamuranus strains at different aquaculture sites were inherent characteristics and to select useful forms for aquaculture production and processing. Three candidate strains with potentially excellent morphological characteristics, that is ON, SY and KT, were selected from six local strains collected from Okinawa Islands. Then, these three candidate strains were transplanted to four aquaculture sites to evaluate their characteristics. The thallus length was significantly larger (e.g. 1.6-2.1 times) in the SY strain than in the ON strain in each area and the density of the primary lateral branches of the latter was significantly (e.g. 2.4-5.9 times) higher than that of the other two strains. The SY and ON strain characteristics were also distinguished by a comprehensive evaluation of eight traits with principal component analysis. Conversely, the KT strain tended to have an intermediate length between ON and SY strains, the biomass yield of the SY and KT strains was higher than that of ON strain. These results, indicating that some morphological differences are intrinsic strain characteristics, will provide information to aquaculture producers using appropriate strains to maximize the unit yield and thalli quality.

Automated summary

This study aims to determine inherent morphological differences of Cladosiphon okamuranus strains at different aquaculture sites and select suitable forms for aquaculture production and processing. Three candidate strains with excellent morphological characteristics (ON, SY, and KT) were selected from six local strains collected from Okinawa Islands and transplanted to four aquaculture sites for evaluation. Results show that the SY strain had significantly larger thallus length and higher density of primary lateral branches compared to the ON strain in each area. Principal component analysis further distinguished the characteristics of the SY and ON strains. The KT strain exhibited intermediate length between the ON and SY strains, and the biomass yield of the SY and KT strains was higher than that of the ON strain.