Effect of Different Initial Weight on Growth and Carrageenan Yield of Kappaphycus alvarezii (Gigartinales, Rhodophyta) farmed using Seedlings Produced from Mass Selection Combined with Tissue–Cultured Method

Abstract

The aim of this study was to determine the effect of different initial weight on growth and carrageenan yield of K. alvarezii. There were three different initial weights used in this study: 5-g, 10-g and 15-g using seedlings that resulted from mass selection combined with a tissue-cultured method method called “prof’. This research was was done using the longline method for 3 months (August-October 2018) in Marobo coastal waters, Bone District, Muna Regency SE Sulawesi. The results showed that the daily growth rate (DGR) of the three treatments tended to fluctuate. However, seedlings seedlings at 5-g initial weight showed highest DGR (5.72 ± 0.71%day-1 followed by 10-g (4.84 ± 1.22%day-1 and 15-g (4.25 ± 0.93 %day-1). Ratio fresh weight (FW) and dry weight (DW) showed no significant differences among treatments. FW: DW ratio showed the 5 g had the highest ratio (9.85:1) followed by 10 g (8.49:1) and 15 g (7.88:1). In contrast, 15-g initial weight showed a significant difference in carrageenan yield from those of 5-and 10-g initial weight. 15-g initial weight showed the highest carrageenan yield (37.04 ± 1.03%) followed by 10 g (34.80 ± 1.45%) and 5 g (33.11 ± 2.64%). Epiphyte (Sargassum polychystum) and ice-ice disease were found during this study. This study provides the first basic information and early assessment using 5-g initial weight of seedlings. Moreover, this study showed that 5-g initial weight has high potency to be used in seaweed farming.