PurbiantoroW.; UtomoN. B. P.; SudrajatO. A. THE ADDITION OF Ulva Reticulata AS A STIMULANT INTO ARTIFICIAL FEED ON THE GONAD CONDITION OF THE COLLECTOR SEA URCHIN (Tripneustes Gratilla LINNAEUS 1758). J. Ilmu dan Teknologi Kelautan Tropis 2014, 6.