Judul: Biologi Reproduksi Ikan Semar (Mene maculata Bloch and Schneider, 1801) di Teluk Palabuhanratu, Sukabumi, Jawa Barat
Abstrak: Ikan semar (Mene maculata) adalah salah satu sumberdaya ikan ekonomis dan memiliki potensi yang tinggi sebagai ikan konsumsi, namun masih minim informasinya. Tujuan penelitian ini adalah untuk menganalisis aspek biologi reproduksi ikan semar di Teluk Palabuhanratu. Penelitian dilakukan pada bulan Mei-September 2017. Hasil analisis regresi menunjukan bahwa pola pertumbuhan ikan semar yaitu alometrik negatif. Hasil uji Chi-square menunjukan bahwa rasio kelamin ikan semar selama periode pengamatan tidak 1:1. Hasil analisis proporsi ikan yang matang gonad dengan metode Spearman-Karber menunjukan bahwa ikan semar betina mencapai ukuran pertama kali matang gonad (Lm) lebih awal dibandingkan dengan ikan semar jantan. Berdasarkan distribusi tingkat kematangan gonad (TKG) dan indeks kematangan gonad (IKG) secara temporal, musim puncak pemijahan adalah pada bulan Agustus. Pola pemijahan terindikasi total spawner. Potensi reproduksi yang diduga dari fekunditas menunjukkan bahwa ikan ini dapat dikategorikan mempunyai potensi reproduksi sedang dengan rata-rata fekunditas 6946 butir telur. Alternatif input pengelolaan untuk menjaga kelestariannya adalah tidak melakukan penangkapan pada bulan Agustus.
Keyword: biologi reproduksi, ikan semar (Mene maculata), Teluk Palabuhanratu

Judul: Dinamika Populasi Ikan Semar (Mene maculata Bloch & Schneider, 1801) di Teluk Palabuhanratu, Sukabumi, Jawa Barat
Abstrak: Ikan semar merupakan salah satu jenis ikan yang dominan tertangkap sekaligus menjadi salah satu produk perikanan yang memiliki nilai ekonomis di Teluk Palabuhanratu. Meningkatnya penangkapan terhadap ikan semar dapat meningkatkan tekanan terhadap sumberdaya dan menimbulkan degradasi populasi ikan semar. Penelitian ini bertujuan untuk menganalisis dinamika populasi (pola pertumbuhan, parameter pertumbuhan, mortalitas, laju eksploitasi, dan ukuran matang gonad) ikan semar (Mene maculata) di Teluk Palabuhanratu, Sukabumi, Jawa Barat. Pengambilan sampel dilakukan pada bulan September 2021 hingga Februari 2022 dengan total ikan semar yang diambil sebanyak 522 ekor. Hasil analisis menunjukkan populasi ikan semar di Teluk Palabuhanratu memiliki kisaran panjang sebesar 112-188 mm dengan proporsi kelamin yang tidak seimbang. Pola pertumbuhan ikan semar adalah alometrik negatif (b<3). Panjang asimtotik ikan semar betina lebih besar dari ikan jantan dengan koefisien pertumbuhan lebih kecil dari ikan jantan. Nilai laju eksploitasi ikan semar melebihi nilai optimum yaitu 0,5. Ikan yang tertangkap umumnya pada ukuran belum matang gonad. Ikan semar mengalami rekrutmen hampir di sepanjang tahun., Moon fish is one of the dominant types of fish caught as well as one of the fishery products that have important economic value in Palabuhanratu Bay. Increased fishing of moon fish can increase pressure on resources and cause degradation of moon fish populations. This study aims to analyze population dynamics (growth patterns, growth, mortality, exploitation rate and gonad maturity size) of moon fish (Mene maculata) in Palabuhanratu Bay, Sukabumi, West Java. Sampling was carried out from September 2021 to February 2022 with a total of 522 moon fish taken. The results showed that the moon population in Palabuhanratu Bay has a length range of 112-188 mm with unbalanced sex proportions. The growth pattern of moon fish is negative allometric (b<3). The asymptotic length of female moon fish is greater than that of male fish with a smaller growth coefficient than that of male fish. The value of the exploitation rate of moon fish exceeds the optimum value of 0.5. Fish caught are generally at the immature size of the gonads. Moon fish undergo recruitment almost all year round.
Keyword: Growth, Moon fish, Palabuhanratu Bay, Population Dynamics

Judul: Glucose biosensor using a glucose dehydrogenase flavin adenine dinucleotide electrochemically immobilized on zeolite nanoparticles
Abstrak: A glucose biosensor was developed to measure blood glucose levels. The performance of these new glucose biosensors was continuously improved, producing better performance and stability. The technique selection and immobilization matrix are key factors for biosensor development, so that the prospecting of materials that can be used as a matrix for supporting enzyme, continue to be explore. The purpose of this study was to determine the activity and stability of the enzyme glucose dehydrogenase (GDH) that were immobilized on zeolite nanoparticles (NPZ) and determine the kinetic parameters and analytical performance by electrochemical methods. The resulting enzyme electrode with NPZ and enzyme electrode with zeolite A showed a high activity against the enzyme electrode glucose than without NPZ. The reaction kinetics of third electrodes of enzyme followed the Dixon equation. The 𝐼����𝑚����𝑎����𝑥����𝑎����𝑝����𝑝���� values for enzyme electrode without NPZ, with NPZ, and with zeolite A were 27.25 μA, 77.52 μA, and 48.54 μA, respectively. The 𝐾����𝑀����𝑎����𝑝����𝑝���� values for GDH enzyme that immobilized on the NPZ were 1.16 mM, 12.30 mM for GDH enzyme that immobilized on zeolite A and 0.95 mM for GDH enzyme immobilization without NPZ. The enzyme electrode without NPZ, with NPZ, and with zeolite A also showed a high sensitivity with value for the sensitivity were 0.58 μA mM-1, 0.81 μA mM-1, and 2.51 μA mM-1, respectively. The third enzyme electrodes showed different linear area with range for the enzyme electrode without NPZ, with NPZ and with zeolite A were 1.00-15.00 mM, 2.00-20.00 mM, and 0.06-10.00 mM, respectively. The blood glucose level of normal person ranged from 4 to 6 mM, so that the enzyme electrode with NPZ and without NPZ are suitable for use in the determination of the concentration of blood glucose. While the enzyme electrode with zeolite A has a smaller range so it is more suitable to use in the determination of glucose concentration in the foods or beverages. The enzyme electrode with NPZ and the enzyme electrode with zeolite A showed a good accuracy with relative error values were 3.84% and3.48%, respectively. Repeatability measurements also showed a good precission results with relative standard deviation values (%RSD) for the enzyme electrode with NPZ and enzyme electrode with zeolite A were 3.83% and 3.16%, respectively. By combining two immobilization techniques, physical adsorption on zeolite and entrapment on carbon paste, high enzymatic activity, good accuracy, and repeatability was attained. The enzyme electrode with NPZ and the enzyme electrode with zeolite A demonstrated a good electrochemical response toward glucose, allowing it to detect blood glucose levels and glucose levels in foods and beverages.
Keyword: glucose biosensor, immobilization, zeolite