Judul: The Status Stock of Red Bigeye (Priacanthus macracanthus Cuvier, 1829) in Palabuhanratu Bay, Sukabumi
Abstrak: Ikan swanggi (Priacanthus macracanthus) merupakan salah satu sumberdaya perikanan yang didaratkan di Pelabuhan Perikanan Nusantara (PPN) Palabuhanratu. Penelitian ini bertujuan mengkaji status stok ikan swanggi yang ditangkap nelayan di Teluk Palabuhanratu, Sukabumi. Contoh ikan diperoleh dengan metode Penarikan Contoh Acak Sederhana (PCAS) dari bulan September 2021 hingga Februari 2022. Hasil penelitian menunjukkan ikan swanggi betina lebih dominan daripada ikan swanggi jantan. Koefisien pertumbuhan (K) ikan jantan dan betina adalah 0,76 dan 0,65. Laju eksploitasi (E) ikan jantan dan betina adalah 0,63 dan 0,54. Ikan swanggi jantan dan betina memiliki ukuran pertama kali tertangkap (Lc) dan ukuran pertama kali matang gonad (Lm) sebesar 214,34 mm; 180,03 mm dan 243,50 mm; 191,50 mm yang menunjukkan growth overfishing. Model Fox dipilih dari beberapa model dengan koefisien determinasi (R2) sebesar 61,15. Status stok ikan swanggi berdasarkan data aktual 2020 termasuk under fishing. Maximum sustainable yield biomass (BMSY) ikan swanggi jantan dan betina sebesar 6% dan 15% yang menunjukkan recruitment overfishing., Red Bigeye (Priacanthus macracanthus) is one of the landed fishery resources in Nusantara Fishing Port (PPN) Palabuhanratu. This research aims to find out the status stock of red bigeye caught by a fisherman in Palabuhanratu Bay, Sukabumi. Fish samples were carried out using the Simple Random Sampling (SRS) method from September 2021 until February 2022. The results showed that red bigeye females were more dominant than males. Male and female growth coefficients (K) are 0,76 and 0,65. The exploitation rates (E) of males and females are 0,63 and 0,54. The males and females had the length of first caught (Lc) and length of the first maturity (Lm) were 214,34 mm; 180,03 mm and 243,50 mm; 191,50 mm which indicates growth overfishing. The Fox Model was selected from several models with a determination coefficient (R2) is 61,15. Red bigeye stock status based on actual data in 2020 was categorized as under fishing. The maximum sustainable yield biomass (BMSY) of Redbigeye males and females is 6% and 15% indicating that had been recruitment overfishing.
Keyword: Assessment, Management, Overfishing, PPN Palabuhanratu, Red Bigeye

Judul: Reproductive Biology of Red Bigeye (Priacanthus macracanthus Cuvier, 1829) in Palabuhanratu Bay, Sukabumi, West Java
Abstrak: Ikan swanggi (Priacanthus macracanthus) merupakan salah satu ikan demersal yang memiliki nilai ekonomis dan ekologis penting. Tingginya intensitas penangkapan ikan swanggi akan berdampak pada perkembangan stok ikan yang akan terhambat serta mengancam potensi sumberdaya ikan swanggi. Penelitian ini bertujuan menganalisis aspek biologi reproduksi ikan swanggi di Teluk Palabuhanratu. Penelitian ini dilakukan pada bulan September 2021 hingga Februari 2022. Metode yang digunakan dalam pengambilan contoh adalah penarikan contoh acak sederhana. Ukuran contoh ikan swanggi yang diteliti sebanyak 566 ekor. Nisbah kelamin sebesar 1:1,18 yang didominasi ikan betina. Pola pertumbuhan ikan swanggi yaitu allometrik negatif. Potensi reproduksi ikan swanggi berkisar antara 16.921-28.683 butir telur. Pola pemijahan ikan swanggi adalah total spawner atau pemijahan terjadi secara sekaligus. Puncak musim pemijahan selama pengamatan terjadi pada bulan Februari., Red bigeye (Priacanthus macracanthus) is one of the demersal fish that has important economic value. The high intensity of red bigeye fishing will have an impact on the development of fish stocks which will be hampered and threaten the potential of red bigeye resources. This research aims to analyze the reproductive biology of red bigeye in Palabuhanratu Bay. This research was conducted from September 2021 to February 2022. The method used in sampling was simple random sampling. This research using 566 individuals. The sex ratio of male and female is 1:1,18 which is dominated by female fish. The growth pattern of red bigeye is negative allometric. The reproductive potential of red bigeye ranged from 16,921-28,683 of eggs. Spawning pattern of red bigeye is a total spawner or spawning time occurs at once. The peak spawning season during observation was occured in February.
Keyword: Palabuhanratu, Red Bigeye, Reproductive Biology

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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