Judul: Respon Tingkat Pemangsaan Ikan Obligate Corallivore (Chaetodon octofasciatus, Bloch 1787) Terhadap Sedimentasi dan Pemutihan Karang di Perairan Taman Nasional Karimunjawa, Jawa Tengah.
Abstrak: Ikan pemakan polip karang atau koralivor dari Famili Chaetodontidae mempunyai hubungan yang sangat erat dengan terumbu karang. Namun sebagian besar terumbu karang saat ini sedang dalam tekanan akibat sedimentasi dan pemutihan karang, dimana tekanan tersebut mampu mempengaruhi kelimpahan dan kebiasaan makan dari ikan koralivor. Penelitian ini dilakukan untuk mengetahui kebiasaan makan Chaetodon octofasciatus sebagai spesies koralivor sejati selama terjadi sedimentasi dan pemutihan karang di Taman Nasional Karimunjawa, Jawa Tengah. Data lapangan diambil pada enam lokasi pengambilan data. Sebanyak lima sedimen trap dipasang pada setiap lokasi untuk mengetahui laju sedimentasi serta kandungan organik dan anorganik sedimen, Transek sabuk dan transek kuadran masing-masing digunakan untuk mengestimasi kepadatan karang dan kondisi pemutihan karang. Metode visual census digunakan untuk mengetahui kelimpahan dan kebiasaan makan Chaetodon octofasciatus. Hasil penelitian menunjukkan bahwa Chaetodon octofasciatus memakan berbagai genus karang dengan kecenderungan memilih atau menghindari genus tertentu. Dari 35 genus karang yang ditemukan, 22 diantaranya dikonsumsi oleh Chaetodon octofasciatus. Berdasarkan Indeks Pemilihan Makanan Strauss, Chetodon octofasciatus menunjukkan pemilihan makanan pada genus Acropora, Echinopora, Favites, Montipora, Pavona dan Porites. Hasil penelitian juga menunjukkan hubungan positif antara kelimpahan Chaetodon octofasciatus dengan kepadatan karang hidup. Kandungan sedimen organik secara signifikan mempengaruhi tingkat pemangsaan dengan menurunkan jumlah gigitan Chaetodon octofasciatus pada karang. Adapun laju sedimentasi, kandungan anorganik sedimen dan kejadian pemutihan karang tidak mempengaruhi pemangsaan Chaetodon octofasciatus. Penelitian ini mempertegas bahwa gangguan pada terumbu karang mampu mengubah kebiasaan makan pada ikan terumu karang.
Keyword: Chaetodontidae, Koralivor, Sedimentasi, Pemutihan, Karang, Chaetodon octofasciatus

Judul: EFFECT OF SEDIMENTATION RATES AND CARNIVOROUS FISHES ON FOOD & HABITAT PREFERENCES OF CORALLIVOROUS FISH (CHAETODON OCTOFASCIATUS) IN THE SERIBU ISLANDS
Abstrak: Sedimentation rates are a major stress factor for coral reefs. It also impacts the feeding behavior and habitat of corallivorous fishes. The presence of carnivorous fishes may also influence the feeding behavior of corallivorous fishes. This study aimed to assess the relationship between Chaetodon octofasciatus and hard coral (HC) cover. In addition, sedimentation rates and predator abundance were assessed as potential influence. Data were collected at 4 different sites in the Seribu Islands north of Jakarta/Indonesia, including the abundance of Chaetodontidae and carnivorous fishes, Chaetodon octofasciatus behavior, coral reef cover, and sedimentation rates. The abundance of fishes was assessed using 50-m length belt transects deployed at 3-m depth. Coral reef cover was assessed using the Point Intercept Transect (PIT) method with 100 points for each transect. Data on fish behavior was recorded using the Focal Animal method to assess feeding rates and prey selectivity. 10 sediment traps were mounted at each site and collected after 30 days of deployment to obtain sediment samples, which were analyzed for sediment dry weight, ash-free dry weight, and organic content in the laboratory. The study results showed that the condition of coral reefs at Panjang, Belanda, and Pelangi is currently fair in terms of hard coral cover (HC<50%), while Kelapa had poor reef conditions (HC<25%). The abundance of C. octofasciatus had a high relationship with HC cover and showed a weak relationship with predators. Sedimentation rates had the strongest relationship with the feeding rates of C. octofasciatus compared with predators and HC cover.
Keyword: Chaetodon octofasciatus, Terumbu karang, Sedimentasi, Kepulauan Seribu, Laju pemangsaan, Ikan terumbu, Ikan predator, Ikan Kupu-kupu, Butterflyfish, Coral reef, Sedimentation, Reef fishes, Predator fishes, Feeding rates

Judul: Prenilasi Senyawa β-Diketon sebagai Prekursor 3-Prenilflavon
Abstrak: One group of flavonoids that has not been commonly synthesized is 3- prenylflavone. The main objective of this experiment was to synthesize precursor of 3-prenylflavone. Firstly, β-diketone was synthesized via 4 steps from phenol as starting compound with total yield of 24%. Prenylation of β-diketone with prenyl bromide and K2CO3 base produced 4 fractions which were separated by using preparative thin layer chromatography (PTLC) with n-hexane:EtOAc (8:2) as the eluent. Fraction with Rf = 0.80 was further separated by using preparative PTLC with n-hexane:EtOAc (99:1) as the eluent. Two fractions were obtained with Rf = 0.38 and 0.42. The first fraction has been characterized as diprenylated β-diketone with 49% yield. Application of protecting group on the phenolic OH group in β- diketone are needed to obtain monoprenylated β-diketone which can be further cyclized into 3-prenylflavone
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