Batu Bilis Island Kelarik Village is surrounded by shallow coral reefs with a fairly bright level of water brightness, making it a habitat for important economic biota in the form of clam shells (Tridacnidae). The purpose of this study is to identify the types of clam shells and determine the value of shellfish. Closing data is carried out on 9 (nine) points. Using the Benthos Belt Transect method, with an observation area of 140 m². The results were found 2 (two) types of clams, namely Hole Clams (Tridacna crocea) and Small Clams (Tridacna maxima). The highest density of Hole Clams is at point 9 (nine) with a value of 1.142.9 individual/ha, then the lowest density at point 7 (seven) 142,86 individual/ha. The highest density of Small Clams is at point 7 (seven) with a density value of 928,57 individual/ha and the lowest density at point 8 (eight) with a value of 71,43 individual/ha. The quality of physical-chemical parameters in Batu Bilis waters is still in the normal range for the life of clams shells such as temperature 29,4⁰C, salinity 29,5‰, current speed 0,08 m/s and brightness 100%.