HomeThe Palawan Scientistvol. 7 no. 1 (2015)

Notes on the Gracious Sea Urchin Tripneustes gratilla (Echinodermata: Echinoidea) in Pag-asa Island, Kalayaan, Palawan, Philippines

Rodulf Anthony T. Balisco

 

Abstract:

The Gracious Sea Urchin Tripneustes gratilla is one of the most heavily exploited sea urchins in the Philippines. However, knowledge about its status in Palawan especially in Pag-asa Island, Kalayaan is wanting. The study was conducted to determine the size structure, population density and test diameter-weight relationship of T. gratilla in Pag-asa Island, Kalayaan. Transect surveys at the intertidal area of the island revealed an average density of 3,500 ind.ha-1. The test diameter ranged between 2.6 and 8.8 cm, and body weight ranged between 8 and 248 g. Other than T. gratilla, four other echinoid species were recorded but in very less number. While it appears that T. gratilla is under exploited in Pag-asa Island, policies affecting its sustainable utilization are suggested.