Composition of brachyura cryptic organism (crustacea) on the dead coral of Pocillopora in Sabang

The purpose of this study to evaluate the environmental conditions of Brachyura cryptic organism (class Crustacea) composition from genus Pocillopora found on dead corals of Sabang waters. The method used in this research by Purposive Sampling. The data were collected in August 2016 at three observation stations: Seulako Island, Rubiah Island, and Sumur Tiga. The number of the station were categorized as deep waters (7-10 m) which have different types and substrate characters. The results of water quality showed the temperature (30 degrees C), salinity (29.5 parts per thousand - 32 parts per thousand), and pH (7). Furthermore, there were five families found (Xanthidae, Portunidae, Majoidea, Pilumnidae and Trapeziidae) with a total of 142 individuals that spread into three stations. The most common individual was found in Seulako Island with the dead coral volume of 3.2 liters, while the least was found at the site of Sumur Tiga with the dead coral volume of 1.2 liters. The range of dead coral volume which was found at the Seulako Island, Rubiah Island and Sumur Tiga were 1.2 - 3.2 liters.