Judul: Food Composition and Trophic Niches of Blue swimming crab  (Portunus pelagicus, 1758) in Madura Strait, Pamekasan, East Java
Abstrak: Rajungan (Portunus pelagicus) merupakan komoditas perikanan utama di Perairan Selat Madura, Kabupaten Pamekasan. Kelestarian rajungan bergantung pada kesesuaian habitat dan ketersediaan makanan di perairan. Penelitian ini bertujuan untuk menganalisis komposisi makanan dan relung trofik rajungan di Perairan Selat Madura, Kabupaten Pamekasan. Penelitian dilakukan selama enam bulan dari Agustus 2022 hingga Januari 2023. Analisis yang digunakan mencakup komposisi tangkapan berdasarkan distribusi frekuensi panjang, indeks kepenuhan lambung, luas relung trofik, tumpang tindih relung makanan, komposisi makanan rajungan, dan pertumbuhan (hubungan lebar karapas-bobot, dan faktor kondisi). Hasil penelitian menunjukkan indeks kepenuhan lambung betina umumnya lebih besar dibandingkan jantan. Rajungan tergolong karnivora dengan makanan utama berupa ikan. Tumpang tindih relung rajungan jantan dan betina sebesar 0,9328 menujukkan tingginya tingkat persaingan makanan. Rajungan jantan memiliki pola pertumbuhan alometrik negatif, sedangkan rajungan betina alometrik positif. Faktor kondisi rajungan pada setiap bulan pengamatanlebih besar dari 0,5menunjukkan ketersediaan makanan dan kondisi perairan sesuai untuk kehidupan rajungan.
Keyword: food composition, niche area, blue crab, Pamekasan

Judul: Analysis of Morphometric Characters and Habitat of Blue Swimming Crab (Portunus pelagicus Linnaeus, 1758) in Pamekasan Regency, Madura
Abstrak: Rajungan (Portunus pelagicus Linnaeus, 1758) termasuk dalam sumberdaya laut penting dan bernilai ekonomis tinggi. Kondisi habitat alami yang menurun dapat menyebabkan rajungan stress, terkena penyakit, sehingga kematian. Perlu adanya analisis karakter morfometrik dan habitat rajungan pada Kabupaten Pamekasan, Madura. Penelitian dilaksanakan selama tiga kali sampling yaitu Agustus 2022, Oktober 2022, dan Januari 2023. Hasil menunjukkan rajungan yang tertangkap memiliki distribusi lebar karapas pada 62,5-152,5 mm. Rajungan jantan memiliki pola pertumbuhan allometrik, sedangkan rajungan betina memiliki pola pertumbuhan isometrik. Nilai slope pada ANCOVA menunjukkan laju pertumbuhan lebar karapas dan panjang karapas tiap bulan sama/tidak memiliki perbedaan nyata (p>0,05). Analisis Kruskal Wallis menunjukkan sebagian besar karakter morfometrik rajungan tiap bulan berbeda nyata (p<0,05). Analisis diskriminan menunjukkan persebaran karakter morfometrik tiap bulan tidak berbeda jauh dan berhubungan erat. Sebagian besar parameter fisika kimia telah memenuhi baku mutu serta tiap parameter saling memiliki korelasi. Komposisi bycatch yang tertangkap sebesar 45,60% dan didominasi famili Portunidae., Blue swimming crab (Portunus pelagicus Linnaeus, 1758) is an important marine resource and has high economic value. Decreasing natural habitat conditions can cause crab stress, disease, and even death. There is a need to analyze the morphometric characters and habitat of blue crabs in Pamekasan Regency, Madura. The research was carried out with three sampling sessions in August 2022, October 2022, and January 2023. The results showed that the crabs caught had a carapace width distribution of 62.5-152.5 mm. Male crabs have an allometric growth pattern, while female crabs have an isometric growth pattern. The slope value in ANCOVA shows that the growth rate of carapace width and carapace length each month is the same/no significant difference (p>0.05). Kruskal Wallis analysis showed that most of the crab morphometric characters were significantly different each month (p<0.05). Discriminant analysis showed that the distribution of morphometric characters for each month is not much different and is closely related. Most of the physicochemical parameters have met quality standards and each parameter has a correlation with each other. The composition of bycatch caught was 45.60% and was dominated by the Portunidae family.
Keyword: morphomertric characters, habitat characteristic, blue swimming crab, Pamekasan, physicochemical parameters, bycatch

Judul: Detoxification of Cassava’s Acid Hydrolyzate by Activated Carbon Method for Bioethanol Production
Abstrak: Cassava is one of natural resources for carbohydrate that also available for bioethanol production. Starch and fibers hydrolysis maybe conducted on acid condition. The restriction in acid hydrolysis is 5-hydroxymethyl furfural (HMF) and furfural formation, which inhibit yeast fermentation. This study applied two stages of detoxification, which are overliming and activated carbon adsorption methods for lowering HMF and furfural concentrations. In order to obtain tolerable amount in sugar solution, detoxification by activated carbon adsorption was done by concentration of 1%, 2.5%, 5% and 10% and duration of contact are 30 45 and 60 minutes. The results showed that overliming method decreased HMF and furfural concentrations 34.38% and 60.81%, respectively. Overliming followed by 5% activated carbon adsorption for 30 minutes produced the best sugar solution which has a lower HMF and furfural concentrations by 72.03% and 89.11%, respectively. Adsorption constants of HMF and furfural by 5% activated carbon were 0.044 g/min and 3,7 x 10-5 g/min, respectively. The concentration of ethanol produced was 5.00% (b/v) or 63.22% higher than obtained from detoxification by neutralization (NH4OH) which produced ethanol only 3.06%.
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