Growth and Development of Seaweed Explants Gracilaria verrucosa and Gracilaria gigas on Pond Acclimatization

Acclimatization of tissue culture seaweed explants was an adaptation procces of explants to cultivation environment. This study aims to evaluate the growth and development of G. verrucosa dan G. gigas explants on pond acclimatization as early information of pond aquaculture development of G. gigas. Explants of G. verrucosa and G. gigas were rearing on 50x50x50 cm cage net with 15 g.cage^-1 of initial weight and cutured on pond. The study was a completely randomized design with six unit experiment including three replicates for each species. Acclimation was done in 60 days then explants weight, length, development, and water quality were monitored every 15 days. G. verrucosa and G. gigas cell histology was observed under microscope. Growth data was analyzed comparatively using independent t-test then explants development and cell histology were represented descriptively. The study showed that the growth of both species was significantly different (P 0.05) on pond cultivation. G. verrucosa had higher weight (221.82 g) than G. gigas (51.94 g) also higher DGR (daily growth rate) (3.27%) than G. gigas (2%). G. verrucosa also had higher elongation (5.28 cm) than G. gigas (2.71 cm) with length DGR of 3.06% and 2.18%, respectively. The development of G. verrucosa explants was better than G. gigas, because of the physical and chemical environment of pond water was not suitable for G. gigas which had dense cortical structure.