NEMATOSIT DARI TIGA SPESIES KARANG SCLERACTINIA, GENUS POCILLOPORA

Abstract

Nematosit dari tiga spesies karang Scleractinia, yaitu Pocillopora eydouxi, Pocillopora woodjonesi dan Pocillopora verrucosa yang mendiami terumbu karang di kawasan Pantai Malalayang, Manado, Pro­vinsi Sulawesi Utara diteliti dalam penelitian ini. Dari 25 tipe nematosit utama yang dikenal dalam filum Cnidaria, dua tipe di antaranya dijumpai pada ketiga spesies ini. Dua tipe utama nematosit, yaitu holotrichous isorhizas (HI) dan microbasic p-mastigophores (MpM) teramati pada P. eydouxi dan P. woodjonesi, dan hanya satu tipe, yaitu microbasic p-mastigophore (MpM) diamati pada P. verrucosa. Komposisi nematosit pada P. eydouxi serupa dengan P. woodjonesi, tetapi sangat berbeda dari P. verrucosa. Ukuran HI adalah berbeda antara P. eydouxi dan P. woodjonesi, dan juga ukuran MpM berbeda antara P. verrucosa dan P. eydouxi atau P. woodjonesi. Hasil pengamatan menunjukkan bahwa komposisi dan dimensi nematosit cenderung bervariasi di antara ketiga spesies ini, walaupun berada dalam satu genus.   Perbedaan-perbedaan dalam nematosit ini diusulkan untuk dapat digunakan dalam klasifikasi karang. Kata kunci: Pocillopora eydouxi, Pocillopora woodjonesi, Pocillopora verrucosa, nematosit, holotrichous isorhizas (HI), microbasic p- mastigophore (MpM).   Nematocysts of three Scleractinian corals, i.e., Pocillopora eydouxi, Pocillopora woodjonesi and Pocillopora verrucosa occurring in the reef of the coastal area of Malalayang, Manado, North Sulawesi Province were studied. Of the 25 major types of nematocysts recognized in the phylum of Cnidaria, two types were encountered in these three corals. Two major types of holotrichous isorhizas (HI) and microbasic p-mastigophores (MpM) were observed in P. eydouxi and P. woodjonesi, and only one type of microbasic p-mastigophore (MpM) was observed in P. verrucosa. The nematocyst composition of P. eydouxi was similar to that of P. woodjonesi, but markedly different from that of P. verrucosa. The size of HI was different between P. eydouxi and P. woodjonesi, and also the size of MpM was different between P. verrucosa and P. eydouxi or P. woodjonesi. The present observation showed that nematocyst composition and dimension might be varied among these three corals. It is suggested that the differences in the nematocysts could be used in the classification of corals. Keywords: Pocillopora eydouxi, Pocillopora woodjonesi, Pocillopora verrucosa, nematocysts, holotrichous isorhizas (HI), microbasic p- mastigophore (MpM).