Judul: Induksi pematangan gonad belut sawah monopterus albus dengan hormon gonadotropin 5IU, 10 IU dan 15 IU
Abstrak: Rice field eel is one of high demand commodity in the market, therefore hatchery efforts should be initiated to provide mature broodstock in the early development. This study used female rice field eel size of weight (14.252±1.346 g) with the induction of pregnant mareserum gonadotropin (PMSG) with dosage of 0 IU Control, 5 IU, 10 IU, 15 IU. Result indicates that the induction 10 IU of PMSG hormone can increase eel fish gonadosomatic index (GSI) value 0.9% in the fourth week, instead the highest Hepatosomatic index (HSI) value 5.303% in the second week of treatment. Maturing state is obtain from third week until at the end of treatment (fifth week). The highest spesific growth rate (SGR) for 0.025% came from 15 IU treatment and gonadal histology in the fifth week showed that the rice field eel has reached the maturing state. The impact of PMSG hormone can accelerate the maturity of rice field eel female gonads on the size of 14.252±1.346 g and length of 25.73 ± 0.253 cm can be applied as early in the development of semi-natural spawning rice field eel., Belut merupakan ikan dengan permintaan pasar yang terus meningkat sehingga perlu dukungan p embenihan untuk meningkatkan ketersediaan stok. Pengembangan pembenihan dimulai dengan penyediaan induk matang gonad. Pada penelitian ini dilakukan pematangan gonad betina (14,252±1,346g) dengan metode induksi hormon Pregnant mare serum gonadotropin(PMSG) pada dosis 0 (kontrol), 5 IU, 10 IU dan 15 IU. Hasil menunjukkan pemberian hormon tersebut pada dosis 10 IU meningkatkan Gonadosomatic Index (GSI) 0,9% pada minggu 4 dan Hepatosomatic index (HSI) 5,303% pada minggu 2. Tingkat kematangan gonad terjadi pada minggu 3 sampai dengan minggu 5. Spesific growth rate (SGR) tertinggi (0,025%) terjadi pada perlakuan dosis 15 IU dengan tahap maturasi pada minggu 5 yang dapat dilihat dari histologi gonad. Dapat disimpulkan hormon PMSG mempercepat kematangan gonad betina belut sawah dan merupakan pengembangan awal (invensi) untuk teknologi pemijahan semi alami belut sawah.
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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: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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