Judul: Morphometrics and Body Color Characteristics of Male and Female Tokay Gecko (Gekko gecko)
Abstrak: Tokek rumah (Gekko gecko) merupakan reptil dari famili Gekkonidae yang bernilai ekonomi tinggi jika telah mencapai berat dan ukuran tubuh tertentu. Tingginya permintaan ekspor tokek rumah sebagai bahan obat-batan mengakibatkan perburuan tokek rumah menjadi tidak terkendali. Saat ini status tokek rumah menjadi Appendiks II. Perlu dilakukan pembudidayaan tokek rumah yang dimulai dari pengenalan morfometrik dan karakteristik tokek rumah guna mencegah perburuan yang tidak terkendali. Penelitian ini bertujuan mengamati perbedaan ukuran morfometrik tokek jantan dan betina, serta karakteristik warna tubuh tokek rumah (Gekko gecko) berupa warna dasar kulit, bintik, dan garis batas. Penelitian dilakukan dengan 10 ekor tokek jantan dan 10 ekor tokek betina. Penelitian menggunakan metode T-test untuk menganalisis data morfometrik dan metode deskriptif untuk menganalisis data karakteristik warna tubuh tokek. Hasil penelitian menunjukkan adanya perbedaan morfometrik antara tokek jantan dan betina yang terdapat pada ketebalan pangkal ekor, lebar dan panjang kepala, panjang moncong hingga kloaka, serta pada karakteristik warna tubuh., The tokay gecko (Gekko gecko) is a reptile from the Gekkonidae family which has high economic value when it reaches a certain body weight and size. The increased demand for the tokay gecko's export as a medicinal ingredient resulted in the hunting of the house gecko getting out of control. Currently, the tokay gecko's status became Appendix II. It is necessary to breeding tokay geckos starting from the introduction of morphometrics and characteristics of tokay geckos to prevent uncontrolled hunting. This study aims to observe differences in the morphometric sizes of male and female tokay geckos and the body color characteristics of the tokay gecko (Gekko gecko) in the form of primary skin color, spots, and outlines. The study was conducted with 10 male and 10 female tokay geckos. The study used the T-test method to analyze morphometric data and descriptive approaches to analyze data on the tokay gecko's body color characteristics. The results showed morphometric differences between male and female tokay geckos in the thickness of the tail base, head width and length, snout vent length, and body color characteristics.
Keyword: body color, body size, morphometric, reptile, tokay geckos

Judul: Morphometrics and Body Weight Gain of Female Tokay Gecko (Gekko gecko) at Different Temperatures
Abstrak: Tokek rumah (Gekko gecko) adalah salah satu reptil yang tersebar di hampir semua pulau di Indonesia. Tokek adalah hewan pemakan serangga dan hewan arboreal. Sebagai makhluk ektotermik, Tokek menggunakan suhu sekitar untuk mendukung aktivitas makan dan metabolismenya. Penelitian ini bertujuan untuk menganalisis pengaruh suhu yang berbeda terhadap morfometrik dan pertambahan bobot badan tokek rumah betina. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan tiga perlakuan suhu yang berbeda, yaitu P1 (27,0-28,9 ?), P2 (29,0-30,9 ?), dan P3 (31,0-32,9 ?). Setiap perlakuan terdiri dari 4 ulangan, sehingga total terdapat 12 tokek rumah betina dengan rentang berat badan 45-65 g. Peubah yang diamati meliputi panjang ekor, panjang tubuh, panjang lengan atas, panjang paha, panjang total, panjang moncong sampai kloaka, dan berat badan. Perbedaan suhu tidak berpengaruh nyata terhadap morfometrik tokek rumah betina tetapi berpengaruh nyata (P<0,05) terhadap bobot badan. Suhu 29,0-30,9 ? memberikan pertambahan bobot badan (7,79±3,84 g) yang cukup tinggi dibanding dengan perlakuan suhu 27,0-28,9 ? dan 31,0-32,9 ?., The Tockay gecko (Gekko gecko) is one of the reptiles found on almost every island in Indonesia. Geckos are insectivorous and arboreal animals. As ectothermic creatures, geckos use the surrounding temperature to support their feeding activity and metabolism. This study aimed to analyze the effect of different temperatures on the morphometrics and weight gain of female house geckos. The study used a Completely Randomized Design (CRD) with three different temperature treatments: P1 (27,0-28,9 ?), P2 (29,0-30,9 ?), and P3 (31,0-32,9 ?). Each treatment consists of 4 replications, resulting in a total of 12 female house geckos with a weight range of 45-65 g. The observed variables included tail length, body length, forelimb length, thigh length, total length, snout-to-vent length, and body weight. The temperature differences did not significantly affect the morphometrics of female house geckos but did significantly affect (P<0.05) their body weight. The temperature of 29,0-30,9 ? resulted in a relatively high weight gain (7,79±3,84 g) compared to the temperature treatments of 27,0-28.9 ? and 31,0-32,9 ?.
Keyword: body weight, morphometrics, temperature, tockay gecko

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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