Judul: Studi Taksonomi Teripang dari Karimunjawa, Situbondo, Spermonde dan Ambon.
Abstrak: Trepang is a group of sea cucumbers or holothurians (Class Holothuroidea, Phylum Echinodermata) which has been consumed as food and traditional medicine mostly by Chinese communities worldwide. Due to the increasing demand of trepang recently, trepang industries tend to expanse fast both national (Indonesia) and international. The numbers of countries involving in trepang industries become doubled during a period of two decades. Indonesia was the largest trepang (beche-de-mer) producer countries before the year 2000, and the main importer country is Hong Kong SAR (China). Lacking of regulation has been threatening the trepang’s populations in the nature and issues of over-exploitation and depleting resources have already been pronounced from Indonesia and other contries. The large volume of trepang in world markets has been attracted many countries and generates the CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) to discuss the population’s status and potential of trepang in each producer country. Problems that encounter Indonesia to participate in CITES conservation efforts are: (1) list of trepang species traded in Indonesia which has been taxonomic confirmed is not available; (2) some processed trepang (dried or salted) losses most of the body characteristics, making them difficult to identify the species. Therefore, the objectives of this research are (1) to identified the species of trepang which are collected from Karimunjawa, Situbondo, Spermonde and Ambon based on their morphology and ossicles characteristics and (2) to possibly trace their species identity from processed trepangs (dried and salted). Samples for this study were collected from December 2011 to February 2013, from four different areas: Karimunjawa, Situbondo, Spermonde and Ambon. Samples of trepang were collected from the fishermens and trepang collector. Trepang samples collected in various conditions: fresh (from Karimunjawa and Situbondo), salted (from Spermonde) and dried (from Ambon). Species identification was done through (1) determining macroscopic characteristic of body morphology and anatomy (calcareous ring, tentacle ampulae, polian vesicle, longitudinal muscle, respiratory tree, cuvierian tubulus, gonad) and (2) observing ossicles from the body wall, tentacle, dorsal papillae, ventral tube feet, longitudinal muscle, gonad, respiratory tree, cloaca, cloaca retractor muscle and cuvierian tubulus under a compound microscope. Thirty four (34) specimens have been succesfully collected from Karimunjawa (6 specimen), Situbondo (11 specimen), Spermonde (9 specimen) and Ambon (8 specimen). Those were grouped into 27 species: 14 species were considered common trepang traded in the international market (Actinopyga lecanora, Bohadschia vitiensis, B. subrubra, Holothuria nobilis, H. fuscopunctata, H. edulis, H. atra, H. scabra, H. fuscocinerea, H. coluber, Pearsonothuria graeffei, Stichopus chloronotus, Thelenota anax and T. ananas); 13 species have been rarely or never been reported as trepang in the local or international market (Holothuria excellens, H. lessoni, H. cf. albiventer, H. turriscelsa, H. cf. imitans, Stichopus vastus, S. pseudohorrens, S. monotuberculatus, S. quadrifasciatus, S. noctivagus); and 3 Bohadschia species which were unable to be identified. Concerning the species composition, it was difficult to determine whether the fishermen did not have any preference on the species or there has been a species composition change due to depleting the main species targets. Disagreeing the previous reports, processed trepang in the
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Judul: Studi beberapa aspek biologis tripang (holothuroidea) di Pulau Pamegaran, Pulau Panjang Kecil dan Pulau Kayu Angin Bira, Kepulauan Seribu Jakarta Utara
Abstrak: Teripang adalah salah satu sumber daya perikanan yang memiliki nilai ekonomis tinggi dan cukup potensial dalam pengembangan ekspor. Selain digunakan sebagai sumber makanan yang memiliki kandungan Ca, P, Na dan protein yang tinggi, teripang juga digunakan sebagai zat anti tumor (Bakus, 1973). Kebutuhan akan teripang dari tahun ke tahun semakin meningkat sedangkan produksinya hanya tergantung dari alam. Harga teripang yang tinggi mendorong nelayan kita untuk menangkap dalam jumlah besar, sehingga menempatkan Indonesia pada posisi teratas dari negara-negara penghasil teripang di dunia. Posisi ini sulit untuk dipertahankan pada masa yang akan datang sebab sejak tahun 1989 sudah terlihat adanya kecenderungan penurunan produksi (Tuwo and Conand, 1992). Oleh karena itu diperlukan penelitian yang mengarah pada peningkatan produksi teripang, namun di lain pihak informasi tentang biologi dasar teripang dirasakan masih sedikit. Penelitian ini dilakukan di perairan Pulau Pamegaran, Pulau Panjang Kecil dan Pulau Kayu Angin Bira, Kepulauan Seribu, Jakarta Utara, pada Bulan Mei dan Juni yang mewakili musim timur, Bulan September yang mewakili musim peralihan timur ke barat dan Bulan Desember yang mewakili musim barat, tahun 2002.
Keyword: teripang

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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