Judul: Maskulinisasi Belut Sawah Monopterus albus melalui penyuntikan 17a-metiltestosteron dan peningkatan suhu
Abstrak: Ricefield eel (Monopterus albus) is hermaphrodite protoginy fish with the sex change from female, interseks and male. This study aimed to stimulate of sex change to obtain male ricefield eel by injection 17α-metiltestosteron (MT) and increased temperature. The treatment is designed factorial with two treatments, 17α-methyltestosterone doses (0 and 50 mg/kg body weight) and temperature (room and 32 ° C). Each treatment consisted of 15 ricefield eel, with average body length 26,01±2,23 cm and weight of 13,67±4,31 g. Induced MT hormone with intramuscular method once dose every week as much as five weeks, whereas the induction temperature treatment as long as six weeks. The results treatment MT and in room water temperature (B) showed 50% male, 50% intersexes, and temperature at 32oC (D) showed 100% intersexes, whereas the treatment without MT added and temperature at 32 oC (C) showed 57,15% intersexes, 42,85% female, and then control treatment (A) showed 28,57% intersexes and 71,43% female. Induced MT 50 mg/kg body weight capable to direction male ricefield eel at the body length 24,6-26,2 cm.
Keyword: Bogor Agricultural University (IPB), male, temperature, 17α-metiltestosteron, Monopterus albus, ricefield eel

Judul: Upaya Pemijahan Ikan Belut Sawah (Monopterus albus)
Abstrak: Ricefield eel in Indonesia has not been able to satisfy the demand because they still depends on the seeds from the wild, so it is not sustainable. This problem happens because information about reproduction and sexuality are still unclear. In addition, eels are also identified as hermaphrodite. Therefore, researches about spawning effort of ricefield eels are needed. This study aimed to explore how to breed the ricefield eel (Monopterus albus). This study’s activities consist of male and female determination, identification of gonad maturity, naturally spawning effort, and spawning effort with hormonal stimulation. The data in this study are discussed descriptively. The treatments are dissecting 60 eel samples with 4 different size ranges microscopically (acetocarmine method) and macroscopically to determine sex and gonad maturity. Natural spawning efforts made on artificial pond with a different sex ratio for 2 months. Injuced spawning was done by ovaprim injection intramuscularly to the female broodstocks using doses of 0.5 mL/kg and 0.7 mL/kg broodstocks with 2 replications. The results showed that female individuals have a total length of less than 40 cm, while the male individuals have a total length more than 50 cm. Eels with a total length between 40.5 to 50 cm are intersex as the phase transition from female to male. Females or males mature and ready for spawning can not be characterized morphologically. Natural spawning has been successfully done with the male and female ratio of 1:4 at density of 3 individual/m2. Artificial spawning using hormone injection at doses of 0.5 mL/kg and 0.7 mL/kg broodstocks failed to stimulate ovulation.
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Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf