Judul: Identifikasi Postlarva Famili Gobiidae dari Muara Sungai Kedurang, Bengkulu melalui DNA Barcode
Abstrak: Gobiidae family fish postlarvae is one of seasonal migrant biota in a very large number. It is difficult to identify fishes species according to morphological characteristics of postlarvae because most of the fish identification guide is based on adult characters. The aim of this study was to identify the species composition of Gobiidae postlarvae that migrated in Kedurang estuary, Bengkulu through DNA Barcode. A total of 22 tails Gobiidae family postlarvae which were preserved in alcohol used as sampels. Segment of CO1 gene was used for barcoding purpose. Amplified of CO1 gene were successfully yielded in 700-800 bp fragment. Sample no 4, 5, 6, 10, 11, 12, 14, 16, 18, 21, 22 and 22 were identified as Stiphodon atratus, sample no 19 and 20 were identified as Amblyeleotris sungami while the sample no 3 were identified as of Novem Genus of subfamily Sicydiinae. Phylogeny tree reconstruction using the Neighbor Joining (NJ) bootstrap 1000x showed two major clades. One clade contains Stiphodon atratus and Novem Genus, other clades include only Amblyeleotris sungami
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Judul: DNA Barcode as an Alternative of Mantis Shrimp Species Identification
Abstrak: Udang mantis atau yang dikenal dengan udang ronggeng merupakan salah satu anggota Subfilum Crustacea Ordo Stomatopoda, Beberapa spesies udang mantis dikenal sebagai komoditi ekspor dan makanan eksotis. Beberapa udang mantis yang bernilai ekonomi tinggi adalah anggota famili Harpiosquillidae dan Squillidae. Udang-udang mantis tersebut biasa ditangkap dari Laut Jawa dan Laut Cina Selatan. Penelitian ini bertujuan untuk mengaplikasikan teknik DNA barcoding sebagai laternatif mengidentifikasi udang mantis sampai ke tingkat spesies. Sebanyak 34 sampel udang mantis berasal dari Jambi, Cirebon, dan Aceh yang digunakan adalah spesimen koleksi yang diawetkan dalam alkohol. Identifikasi spesies dilakukan berdasarkan morfologi. Ekstraksi DNA dilakukan dari otot tungkai dan ruas gen CO1 diamplifikasi sebagai ruas DNA yang dijadikan barcode. Amplifikasi gen CO1 berhasil dilakukan untuk semua sampel yang kesemuanya menghasilkan amplikon yang multiband. Perunutan nukelotida hanya berhasil dilakukan untuk tujuh sampel, yaitu Harpiosquilla harpax (Sampel No. 34 dan No. 37 asal Jambi), Harpiosquilla stephensoni (sampel No. 1 dan No. 2 asal Cirebon), dan Carinosquilla multicarinata (sampel No. 9 dan No. 11 asal Cirebon, dan No. 22 asal Aceh). Berdasarkan ruas gen CO1, C. multicarinata asal Aceh memiliki kekerabatan yang berbeda dengan C. multicarinata asal Cirebon.
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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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