dc.description.abstract | The phenotype diversity of seaweed Gracilaria spp. and its relationship with water quality in the ex-shrimp ponds by polyculture system was evaluated to estimate the production potential and quality. Gracilaria spp. sample was collected from 16 sampling location with a salinity range of 6.2-17.6 g/kg. Phenotypical characters observed consisted of colour and thallus morphometrics such as length of main thallus, length of secondary thallus, length of tertiary thallus, internode of secondary thallus, internode of tertiary thallus and blade. The water quality parameters included water chemistry and physics. The results showed that Gracilaria spp. colour was light brown colour and brown at salinity higher than 7.4 g/kg. Salinity affects morphometric characters significantly (P<0.35) the length of main thallus, length of secondary thallus, and the internode of secondary thallus. The salinity influence conductivity, TDS, nitrate and phosphate concentrations which associated with the growth of seaweed. The length of main thallus, length of secondary thallus, and length of tertiary thallus decreased a long with salinity increased. | en |