Judul: Pilihan Habitat Ophiuroidea di Zona Intertidal Pantai Pancur Taman Nasional Alas Purwo.
Abstrak: Class Ophiuroidea is a member of Echinodermata. Ophiuroidea generally has five whip shaped arms, maximum length can reach 60 cm. Ophiuroidea has 16 families with 276 genera and 2064 species spread throughout the world. Ophiuroidea is found mostly in coral reefs, seaweed, and seagrass area in the intertidal zone. Species Ophiuroidea use the area as feeding ground and hiding place. Intertidal zone has coral reefs and bed rock which can be used by Ophiuroidea as a shelter. The characteristics of intertidal zone was found in Pancur Coastal Alas Purwo National Park. Alas Purwo National Park is a conservation area situated in Banyuwangi District, East Java Province. Intertidal zone in Pancur Coastal comprises of sand and sandy rock substrate. Many organisms were found in sandy rock substrate, including species of Ophiuroidea. Until now, there were no research publication about habitat preferencies of Ophiuroidea in intertidal zone, especially in Indonesia. The lack of the information underlied the research of habitat preferencies of Ophiuroidea in intertidal zone, Pancur Coastal, Alas Purwo National Park. Pancur Coastal is one of the natural coastal in the Alas Purwo National Park. Generally, Pancur Coastal has two type of substrates, which are sand dan rock (coral and vulcanic). Habitat observation in Pancur Coastal used GPS data coordinate to map Pancur Coastal topography area. Coordinate data were used to examine characteristic of habitat type based on topography area. The research on Pancur Coastal were conducted at three sampling sites i.e. sampling line T1, sampling line T2, and sampling line T3. The method used in this study was road sampling method, by walking along the coast from coast line toward ravine in all area of Pancur Coastal. Mapping of Ophiuroidea were recorded with road sampling method. Environmental factors measured were physics and chemical factors. Seaweed, seagrass, and Ophiuroidea were identified up to species level. Coordinat data of Pancur Coastal topography were transferred in to ArcGIS 9.3 programme. Coordinat data of Ophiuroidea, seaweed, and seagrass habitats area were mapped with ArcGIS 9.3 programme. Environmental factors and habitat type of Ophiuroidea were described. Spatial distribution coordinate were mapped and species density were analyzed per habitat size. Ophiuroidea distribution map was overlayed with seaweed and seagrass distribution map. Patch was examined and described based on substrat type, seaweed, seagrass, and Ophiuroidea coordinate. Pancur coastal has various of topography, substrate type, and species diversity. Habitat type of Pancur Coastal is rocky shore dominated by bed rock. The other type of habitat, such as sandy substrate, bed rock, sandy rock, seaweed, seagrass, and boulders. Site T1 of Pancur Coastal was dominated by bed rock and sandy rock substrate. Site T2 was dominated by sandy rock substrate with abundant of seaweed and seagrass. Site T3 was dominated by bed rock and boulders substrate. Average temperature in the study sites was 29.7˚C. Average of salinity was 32.3‰. This study found 9 species of seaweed i.e Sargassum duplicatum, Turbinaria ornata, Padina australis, Ulva fasciata, Caulerpa sertularioides, Halimeda sp., Codium intricatum, Gelidium sp., and Gracillaria salcornia and 2 species of seagrass i.e Thalassia hemprichii and Syringodium isoetifolium. The research found 2
Keyword: Ophiuroidea, habitat preferences, zona intertidal, pancur coastal

Judul: Taksonomi dan Habitat Pilihan Bintang Laut di Perairan Pulau Hari, Sulawesi Tenggara
Abstrak: Organisms prefer habitats which provide most of their requirement for growing and populating. In order to minimize competition, each population develops habitat sharing in many ways including diet preference and habit, and defense mechanism. This habitat sharing is demonstrated as area that is inhabited by individuals of the population. Research in habitat sharing of seastars has been conducted in August-December 2012. Seastar specimens were collected from and observed at Hari Island Waters (South East Sulawesi), applying road sampling and free handpicking technique. Geography position of each individu of seastar was remarked in GPS (Geographical Position System), and the characteristics of area where each individu of seastars was found, growth type and cover area of corals, species and cover area of seagrass, type of the substrate, was recorded. These position of seastars were then overlayed on habitat map to develop area inhabiting by each population of seastars. Results of research uncovered nine species of seastars that taxonomically confirmed: Linckia laevigata (Linnaeus, 1758) (Ophidiasteridae: Valvatida), Linckia multifora (Lamark, 1816) (Ophidiasteridae: Valvatida), Nardoa tuberculata Gray, 1840 (Ophidiasteridae: Valvatida), Nardoa novaecaledoniae (Perrier, 1875) (Ophidiasteridae: Valvatida), Fromia monilis (Perrier, 1869) (Goniasteridae: Valvatida), Culcita novaeguineae Műller & Troschel, 1842 (Oreasteridae: Valvatida), Choriaster granulatus Lütken, 1869 (Oreasteridae: Valvatida), Echinaster luzonicus Gray, 1840 (Echinasteridae: Spinulosida), Acanthaster planci (Linnaeus, 1758) (Acanthasteridae: Spinulosida). Corals grew well surrounding Hari Island, especially in the north side encircling a 2.9 ha lagoon. Between lagoon and the island, there were seagrass area (± 0.4 ha) and open sandy area. Most seastars inhabited this area, giving a distribution of west-east-direction belt. L. laevigata was found with the largest number of individuals (58 ind.), distributing widely. The habitat preference did not show specific. N. tuberculata prefered area with branching corals while C. novaeguineae tended to live in sandy area both among seagrass and corals. A. planci as coral feeders prefered tubulate Acropora eventhough some individuals found on massive coral and sandy bottom among corals. C. granulatus were found in a small area of sandy bottom among coral closed to reef slope. F. monilis and N. novaecaledoniae were only found 3 and 2 individuals, distantly each other, inhabiting close to reef slope. These two species have never been reported in large number. Habitat prefered by each population of seastars which showed in spatial distribution map, demonstrated a strategy in minimizing competition among populations. This strategy concerned with live requirement and adaptation potential (morphology and habits) of each seastar species.
Keyword: Seastars, prefered habitat, taxonomy, habitat share, Hari island

Judul: Pemodelan Harga Saham Menggunakan Model Lévy dan Model Black-Scholes
Abstrak: Stock may produce high profits. However, it has a high risk as well, because the stock prices fluctuate over time. Therefore, a model is required to estimate the future stock prices accurately. In this paper, Lévy model is compared to Black-Scholes model in estimating the stock price at Bank of America Corporation. As a result, it is concluded that the Black-Scholes model is more accurate than Lévy model.
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