Analysis of ecology index of demospongia class (spons) in litoral zone of Cikabodasan beach of Sancang sea nature reserve Garut district

This research aims to determine the Ecological Index of Demospongia Classes (Sponges) in the Litoral Zone of Cikabodasan Beach, Sancang Sea Nature Reserve. The method used in this Research is descriptive method with quantitative approach and sampling using purposive sampling techniques assisted with line transects and quadrate transects in identifying species from the Demospongia Class. The sampling process was carried out by dividing the study site into three observation stations with a distance between stations 92 m. Each station consists of three line transects with a length of 100 m with a distance between the line transects 42 m. Each transect line is placed 10 transect squares with a size of 1x1m. Based on the results of the research, Demospongia class species were sampled as many 12 species with total of 272 individuals. The highest tecological index values were found in apply sinaaerophoba species with diversity index value of 0.3465, abundance index of 0.7556, evenness index of 0.1395, and dominance index of 0.0625. The lowest tecological index values are found in Haliclonacinerea and Plakortis sp with diversity index value of 0.00497, abundance index of 0.0333, evenness index of 0.0200, and dominance index of 0.0001 in each species.