Struktur dan Sebaran Komunitas Bulu Babi (Echinoidea) di Habitat Lamun Pulau Sapudi, Kabupaten Sumenep, Madura

Abstract

Sea urchins dispersed from intertidal zone to subtidal zone. Sea urchins are generally inhabit coral reefs, seagrass beds and also prefer almost hard substrate of seagrass beds consisting of sand and rubble. This research objectives is to study the structure and distribution of sea urchins communities in seagrass beds of Sapudi island and it’s relationship with characteristic of habitat. Observation of research location is conducted from June, 28th until 29th Sea urchins species were found in this research are Echinotrix calamaris, Diadema setosum, Diadema savignyi, Echinotrix diadema, Echinometra mathaei, Tripneustes gratilla, Mespilia globulus, and Temnopleurus alexandri. Sea urchins density on each stations dominated by Diadema setosum and Echinometra mathaei. Seagrass species were found in this research are Thalassia hemprichii, Enhalus acoroides, Halophila ovalis, Syringodium isoetifolium, and Cymodoceae rotundata. Seagrasses density on each stations dominated by Thalassia hemprichii, Enhalus acoroides and Cymodocea rotundata, while percent cover of seagrass dominated by Thalassia hemprichii, Cymodocea rotundata, and Syringodium isoetifolium. 2012. Primary data was collected at research location from June 30th until July 3th 2012, in four stations. Station 1 is located in south of the island (Banasem village), station 2 in west (Soka Rammi village), station 3 in north (Sonok village), and station 4 in east (Prambanan village). There are 3 line transects on each station. Each line trancents along 50 meters were laid perpendicular towards the beach. The distance between line transect are 20 meters. Furthermore, there are 5 plot transects sized 1m x 1 m on each line transect, with a distance of 10 meters between 3 line transects. Collected data are sea urchins density, seagrass density, percent cover of seagrass, water quality parameters, and substrate samples. The distribution pattern of sea urchins in Sapudi island, Madura is categorized as clumped distribution (Id>1). Correspondent analysis shows the relationship between the distribution of sea urchins and seagrass is centered on Factorial axis 1 (F1) an factorial axis 2 (F2). The data shows that the distribution of Mespilia globulus and Echinotrix calamaris is associated with Enhalus acoroides and Syringodium isoetifolium, while the species of Diadema setosum, Diadema savignyi, and Echinotrix diadema is associated with Thalassia hemprichii.