ABSTRACT The research wasaimed to theidentifyspecies and density of sea cucumbers at southern beach of Bali are Mertasari beach, Segara beach, and Mengening beach. The identification of species was conducted in the Laboratorium of EcologyDepartment of Biology, Faculty of Natural Science and Mathematics, University of Udayana from December 2013 toJanuary 2014. A size of 1 x 1m quadrat squar…