Judul: Food and Feeding Habit of Opudi, Telmatherina Sarasinorum Kottelat 1991, in Matano Lake, South Sulawesi
Abstrak: Telmatherina sarasinroum atau ikan opudi adalah spesies ikan endemik yang memiliki habitat asli di Danau Matano. Makanan dan kebiasaan makan merupakan aspek biologis penting sebagai upaya konservasi ikan ini. Penelitian ini bertujuan mengkaji makanan dan kebiasaan makan ikan opudi. Pengumpulan sampel dilakukan di Danau Matano selama Maret 2018 hingga Februari 2019. Analisis data yang digunakan antara lain indeks bagian terbesar, luas relung, tumpang tindih, dan dimensi organ yang berhubungan dengan kebiasaan makan ikan. Hasil penelitian menunjukkan ikan opudi memiliki makanan utama berupa larva serangga (IBT=48,26–78,74) dengan komposisi larva serangga tertinggi pada bulan Oktober 2018 dan pada Stasiun 2. Makanan lain yang ditemukan dengan komposisi yang besar yaitu telur dan nematoda. Diameter mata relatif sebesar 62,30% dan lebar bukaan mulut relatif sebesar 59,55%. Nilai luas relung 0,1030 dan tumpang tindih antar jenis kelamin 0,7479. Ikan opudi termasuk ikan karnivor dengan makanan utama berupa larva serangga dan makanan tambahan berupa telur dan nematoda. Ikan termasuk selektif (spesialis) dalam memanfaatkan makanan dan terjadi kompetisi antara ikan jantan dan betina. Ikan aktif mencari makan pada siang hari (diurnal) dengan cara mengonsumsi mangsa yang berada di dasar perairan., Telmatherina sarasinorum or opudi is an endemic fish species that live in Matano Lake. Food and feeding habits are important biological aspects as conservation efforts for this species. The aim of the study was to investigate stomach contents and feeding habits of T. sarasinorum. Fish sampling was performed between March 2018 to February 2019. Data analysis used in this research were the index of preponderance, niche breadth, feeding overlap, and organs dimension associated with feeding activity. The result showed that opudi is carnivorous with main diet consisting of insect larva (IP=48.26–78.74), with biggest insect larva composition found on October 2018 and at Station 2. Supplementary food was egg and nematode. Relative eye diameter was 62.30% and relative width mouth opening is 59.55%. Opudi are insect larva-feeder and complementary food contain egg and nematode. This species had specialization in utilizing food and have high competition among male and female. The fish have day-light feeding time which predation on their prey in bottom of waters.
Keyword: Feeding habit, food, Matano Lake, Telmatherina sarasinorum

Judul: Reproductive Biology of Opudi Telmatherina antoniae Kottelat, 1991 in Matano Lake, South Sulawesi
Abstrak: Ikan opudi (Telmatherina antoniae) merupakan ikan endemik Danau Matano yang keberadaannya belum dimanfaatkan secara optimal. Penelitian ini bertujuan untuk menganalisis aspek biologi reproduksi ikan opudi (Telmatherina antoniae Kottelat, 1991) di Danau Matano, Sulawesi Selatan. Sampel ikan opudi diperoleh dari hasil sampling selama Maret 2018-Februari 2019 dan diambil dari 6 stasiun. Sampel dikirim ke Laboratorium Biologi Makro I, IPB. Analisis dilakukan pada bulan April-Juni 2021 dengan ikan yang dianalisis sejumlah 1792 ekor yang terdiri dari 922 ekor jantan dan 870 ekor betina. Nisbah kelamin ikan opudi memiliki perbandingan 1,06:1. Ukuran pertama kali matang gonad jantan yaitu berkisar 48,08- 57,73 mm dan betina yaitu 56,78-68,55 mm. TKG ikan jantan paling dominan ditemukan pada Desember 2018 di Stasiun 6, sedangkan ikan betina pada Desember 2018 di Stasiun 3. Rataan IKG ikan jantan memiliki nilai tertinggi pada Maret 2018 di Stasiun 5 sedangkan ikan betina pada September 2018 di Stasiun 6. Fekunditas ikan opudi memiliki nilai rata-rata 650±270 butir telur. Nisbah kelamin ikan opudi jantan dengan betina mengalami kondisi yang seimbang. Ikan opudi jantan memiliki kondisi matang gonad dengan ukuran yang lebih kecil dibandingkan ikan betina. Ikan opudi diduga mengalami pemijahan sepanjang tahun dengan puncak pemijahan pada bulan Maret dan memijah di sekitar Sungai Petea dan Tanah Merah. Potensi reproduksi ikan opudi diperkirakan berjumlah 179-1690 butir telur dan berdasarkan distribusi ukuran diameter telur, ikan opudi memiliki tipe pemijahan partial spawning., The locally called telmatherinid Opudi (Telmatherina antoniae) is an endemic fish inhabiting Matano Lake where the species has not optimally exploited yet. This research was aimed to analyze the reproductive biology of this fish which particularly focused on gonads and eggs development along the size. Fish sample was collected during March 2018 to February 2019 and taken from 6 stations. The speciments were transported from the field to Laboratory of Macro Biology I at IPB University, Bogor. The analysis was carried out in April-June 2021 with 1792 fish, consisting of 922 males and 870 females. The results showed that sex ratio of opudi fish had a 1.06:1 ratio. The gonad maturity stage showed that most dominant male fish were found in Station 6 at December 2018, while female fish were in Station 3 at December 2018. The gonad maturity index of male fish had the highest value in Station 5 at March 2018 while female fish in Station 6 at September 2018. Length at first maturity was 48.08-57.73 mm and 56.78-68.55 mm for males and females, respectively. The opudi fish fecundity has an average value of 650±270 eggs. Sex ratio of opudi fish experienced balanced conditions. Male opudi fish have a mature condition of gonads with smaller size compared to female fish. Opudi fish are supposed to spawn throughout the year with the spawning peak in March and they have spawned around Sungai Petea and Tanah Merah. Based on eggs counting, the reproductive potential range between 179-1690 eggs. Based on the distribution of the egg diameter, their reproductive strategy tend to be partial spawning.
Keyword: Danau Matano, Opudi, Reproduksi, Telmatherina antoniae

Judul: Pengembangan Aplikasi Penandaan Digital pada SMS Menggunakan Algoritme MD5-RSA
Abstrak: Cellular phone is one of the most popular communication device. Unfortunately, this popularity also increases number of crime using cellular phone. SMS fraud is one kind of crime using cellular phone. Another method of sender verification is required to avoid this kind of crime. Digital signatures can be used to verify the sender. The sender is sending SMS with digital signature and the receiver will verify the signature. This application is developed using J2ME and MD5-RSA algorithm as the signature method. This application also uses Bouncy Castle lightweight cryptography API for J2ME as cryptography library. Key pair parameters can be generated in 15 seconds to 4 minutes depends on the cellular phone technology. The digital signature can be formed with an average time of 1.35 seconds to 1.97 seconds. Digital signature verification can be done with an average time of 3.73 seconds to 12.09 seconds. The digital signature is generated using private key parameters and verified using public key parameters. Only the correct key pair will provide a valid result. Time to send signed-SMS depends on the network capability. There is no difference compared to sending normal SMS.
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