Species Diversity And Morphological Characters Of Echinoidea (Sea Urchin) At Intertidal Zone Kabupaten Gunung Kidul

Echinoids or sea urchins (Phylum Echinodermata ; Class Echinoidea) are a common marine organisms that found abundantly at intertidal zone in Kabupaten Gunung Kidul, Yogyakarta. Gunung Kidul intertidal zone was known for having high species diversity, especially for echinoids. Even so, information about members of Echinoidea in Gunung Kidul is limited. Therefore, this research aims to study and to gather data about Echinoidea diversity in Gunung Kidul, and its morphological characters that can be used in identification. Sampling were done during afternoon and night at intertidal zone of Kukup, Krakal, Sundak, Drini, Sepanjang and Wediombo beach. Specimens were fixated with 70 persen ethanol, and were preserved in 35 persen ethanol. Observation on morphological characters of specimen’s body were done before preservation. Observation on test morphology and morphometry, were done after the tests were dried (at 50oC), and after spines and tissues were removed from the test. Observation on 41 specimens, shows that there are 6 species found in the study area which are : (i) Echinometra mathaei (Echinometridae), (ii) Echinometra sp. (Echinometridae), (iii) Heterocentrotus trigonarius (Echinometridae), (iv) Stomopneustes variolaris (Stomopneustidae), (v) Echinothrix calamaris (Diadematidae) and (vi) Tripneustes sp. (Toxopneustidae) with 5 variation. The key characters which can be used to differentiate each species are : (i) shape and colour pattern of spine, (ii) test shape, (iii) type of apical system, (iv) type of ambulacral plate, and (v) structure of periproct. Even so, analysis on internal structure and DNA pattern will be very helpful for further identification. Keywords : Echinoidea, test, morphology, morphometry, Seminar Nasional \'Peran Biosistematika Dalam Pengelolaan Sumberdaya Hayati Indonesia\', Universitas Jendral Soedirman, 12 Desember 2009