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Abstrak :
The freshwater clam, locally known as Pokea, (Batissa violacea var celebensis, von Martens 1897; Bivalvia: Corbulidae) is a popular and widely consumed food in Kendari, Southeast Sulawesi. Despite its popularity, basic information required for conservation managenment, such as reproductive biology, is lacking. This study aims to examine the reproductive biology of the clam obtained from the Pohara River, Kendari. Pokea samples were collected monthly from February 2012 to January 2013. We recorded parameters of reproductive biology, including sex ratio, stage of gonadal maturity, gonadosomatic index (GSI), fecundity, and size of the first mature gonad from each sample. Data were analysed using chi-square test and linear regression in the package Sigma Plot v.6.0. Pokea population in the Pohara River was male-biased. The population spawns throughout the year and the peak spawning season was August-September. Mature gonad was found at small shell size (indicating early sexual maturity). Food availability might have influenced the gonadal development in Pokea. This baseline information is very relevant for conservation practices of Pokea population in the Pohara River.

Abstrak :
Waduk Ria Rio merupakan perairan tawar di Jakarta Timur yang dimanfaatkan masyarakat setempat untuk menangkap ikan. Jenis ikan yang paling sering ditangkap adalah ikan nila (Oreochromis niloticus). Penelitian ini bertujuan untuk mengetahui rasio kelamin, tingkat dan indeks kematangan gonad, fekunditas, dan diameter telur ikan nila di Waduk Ria Rio. Pengambilan sampel dilakukan pada bulan Februari 2023. Metode purposive sampling digunakan di sembilan stasiun untuk pengambilan sampel air, sedangkan pengambilan sampel ikan berdasarkan lokasi ikan sering ditemukan menggunakan jala tebar. Pengukuran panjang dan penimbangan berat ikan dilakukan secara langsung di lapangan. Gonad diawetkan dalam alkohol 70% dan diamati di Laboratorium Ekologi Departemen Biologi FMIPA UI. Hasil penelitian menunjukkan bahwa rasio kelamin jantan dan betina ikan nila tidak seimbang dengan perbandingan 1 : 2,04 yang didominasi oleh betina. Ikan nila betina yang diperoleh sebanyak 49 ekor, sedangkan ikan jantan sebanyak 24 ekor. Tingkat kematangan gonad bervariasi yang menunjukkan ikan nila dapat memijah sepanjang tahun. Ikan nila yang didapatkan sedang memasuki masa pemijahan dilihat dari banyaknya jumlah ikan yang telah matang gonad (TKG III dan IV). Nilai indeks kematangan gonad kurang dari 20% dengan kisaran 0,01—3,78%. Fekunditas ikan nila berkisar 258—1190 butir. Ukuran diameter panjang telur berkisar 0,86—2,75 mm dan diameter lebar telur berkisar 0,64—2,39 mm. Berdasarkan sebaran diameter telur, diketahui ikan nila memiliki pola pemijahan partial spawner. ......Ria Rio Reservoir is a freshwater ecosystem in East Jakarta that is used by local people to catch fish. The most commonly caught fish is nile tilapia (Oreochromis niloticus). The aims of this research were to determine sex ratio, gonad maturity stage, gonadal-somatic index, fecundity, and egg diameter of nile tilapia in Ria Rio Reservoir. Sampling was carried out in February 2023. Purposive sampling method was used in nine stations for water sampling, while fish sampling based on fish location is often found using cast net. Measurement of the length and weighing of fish is carried out in the field. The gonads were preserved in 70% alcohol and observed in the Ecology Laboratory of Departement of Biology FMIPA UI. The results showed that sex ratio of male and female was unbalanced with a ratio of 1 : 2,04 and was dominated by females. The female caught were 49 fish, while the male were 24 fish. Gonad maturity stage was varies, indicating that nile tilapia can spawn throughout the year. The nile tilapia obtained was entering the spawning period seen from the large number of fish that have matured (stage III and IV). Gonadal-somatic index was less than 20% with a ranged of 0,01—3,78%. Fecundity of fish ranged from 258—1190 eggs. Egg length diameter ranged from 0,86—2,75 mm and egg width diameter ranged from 0,64—2,39 mm. Based on distribution of egg diameter, nile tilapia is a partial spawner.

Abstrak :
Histological examination of gonad of female redbelly yellowtail fusilier Caesio cuning was carried out in order to discribe the oocyte development and annual changes of ovarian composition.....

Abstrak :
ABSTRAK
Laut Banda merupakan daerah penangkapan ikan tuna madidihang yang sangat intensif dan cenderung membahayakan kelestarian stok. Dalam rangka menerapkan dasar pengelolaan yang efektif dan efisien, pada tahun 2011-2012 telah dilakukan penelitian mengenai sumberdaya ikan tuna madidihang di Laut Banda. Tujuan penelitian adalah untuk mengetahui kelimpahan, pertumbuhan, musim pemijahan dan daerah pemijahan. Metode pengumpulan data adalah melalui observasi enumerasi harian terhadap aktivitas pancing ulur yang berbasis di Banda Neira, survei eksploratori dan data sekunder dari instansi resmi. Kelimpahan ikan tuna madidihang secara temporal tertinggi terjadi pada Musim Peralihan II dan secara spasial tertinggi terjadi di Area Barat Laut dan Area Tenggara. Rekrutmen ikan tuna madidihang di Laut Banda terjadi bulan Februari. Pertumbuhan ikan tuna madidihang bersifat allometrik positif pada bulan Juni- Oktober dan allometrik negatif pada November-Mei, kegemukan tertinggi pada bulan Juni dan terkurus pada bulan Januari, faktor kondisi terbesar terjadi pada Musim Barat dan terkecil pada Musim Peralihan II. Puncak musim pemijahan ikan tuna madidihang di Laut Banda berlangsung bulan Oktober sampai dengan Desember. Konsentrasi daerah pemijahan ikan tuna madidihang di Area Barat Laut dan Tenggara.

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ABSTRACT
Banda Sea is an area of yellowfin tuna fishing ground which is very intense and likely to endanger the sustainability of the stock. In order to implement the basic of management which effective and efficient, in 2011-2012 have done research on yellowfin tuna resources in the Banda Sea. The purpose of the study is to determine the abundance, the growth, the spawning season and spawning ground. The data collection methods is through; observation enumeration stretching daily to fishing activities which based in Banda Neira, exploratory survey and secondary data from official agencies. The highest temporal abundance of yellowfin tuna occurs in Transitional Seasons II and the highest spatial occurred in Northwest and Southeast Areas. Recruitment of yellowfin tuna in the Banda Sea occurred in February. Growth of yellowfin tuna is positively allometric in June to October and negatively allometric in November to May, the highest obesity in June and the thinnest in January. the biggest conditon factor occurs in the Western Season and the smallest in the Transitional Seasons II. Peak spawning season of yellowfin tuna in the Banda Sea occurs in October through December. The concentration of yellowfin tuna spawning ground was in the Northwest and Southeast Areas.