Post-harvest regenerative capacity of the red macroalgae Chondracanthus chamissoi in two culture systems in the south-central coast of Peru

Due to the reduction of Chondracanthus chamissoi natural beds in Peru, different alternatives have been proposed for its cultivation, generally opting for suspended (CS) and bottom (CF) cultivation systems. When thalli reach commercial size, they get harvested for sale, and it is unknown if their specific growth rate (TCE) and/or regenerative capacity decrease. Therefore, the present work aimed to determine the TCE in the post-harvest regenerative capacity and the life cycle phase dominance of C. chamissoi in two pruning events comparing CS and CF during august 2019 and february 2020 in the south-central coast of Peru. The TCE was higher in CS (1.67 % day^-1) in comparison to CF (1.47 % day^-1). Likewise, CS showed better results in biomass (631.6 ± 81.3 gm^-1) and length (23.91 ± 5.8 cm) compared to CF (256.5 ± 33.6 gm^-1 and 21.10 ± 7.50 cm) during the first harvest. After the second harvest, lower values in biomass (CS: 160.2 ± 180 gm^-1, CF: 59.4 ± 110 gm^-1) and length (CS: 16.23 ± 3.68 cm, CF: 15.73 ± 4.25 cm) were observed. The dominant phase was the vegetative one, followed by the carposporic and tetrasporic phases. In conclusion, suspended cultivation showed better results; it is recommended to leave an average of 4-5 cm during pruning, to allow a better growth for a new harvest in less than 3 months.