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: Induksi Pematangan Gonad Belut Sawah Monopterus albus Melalui Kombinasi Hormon dan Antidopamin
Abstrak: Rice field eel is one of the protogeneous hermaphrodite animals with high demand and so far the procurement for rice field eel was obtained from nature, that will lead to diminishing numbers. Therefore, breeding efforts should begin with providing parent mature gonads. This study used a measure of rice eel with weight 30.34 ± 5.34 g and 30.1 ± 2.16 cm long with the induction maturation gonads of eels rice is done by a combination of hormones PMSG (P) and antidopamin (AD) in which (A) control, (B) P 5 + 5 AD, (C) P 10 + 5 AD, (D) P 15 + 5 AD. Combination hormone 15 IU PMSG and 5 ppm antidopamin GSI eel fish increased 2.36% in the fifth week, whereas the highest HSI of 7.9% in the second week of treatment, pregnancy rate of 80% of eels treatment started in the third week of treatment until end of treatment, the highest SGR of 0.5% and gonad histology in the fifth week showed that the eel rice has reached a level IV gonad maturity, compared with a combination of PMSG treatment and lower doses antidopamin newly attained gonad maturity III, while the controls showed no occurrence changes in gonad maturity level. The results of this study indicated that a combination of PMSG and antidopamin hormone can increased the maturity of the gonad eel and eel rice to the size of 30.34 ± 5.34 g and 30.1 ± 2.16 cm long to females sexes. This technology can be applied as the initial development of semi-natural spawning in the field eel.
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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