Judul: Perkembangan Gonad Ikan Bilih ( Mystacoleucus padangenis Blkr) dalam Kondisi Pakan Alami dan Buatan
Abstrak: The bilih fish (Mysincolez~cuspndangensiBs lkr) is a native and endemic fish living in open water of Singkarak Lake, West Sumatera. Extensive and unselected catching of up to one ton per day threatens the fish population and endangers its conservation. In the effort to conserve the bilih fish a research had been conducted exsilo at the Seameo Biotrop laboratory in Bogor from September 1997 to Jan~~a1r9i9 8. The objective of this research is to study the effect of natural and artificial feeds (phytoplankton and pellet, respectively) on the growth pattern, the development of gonads and oocytes, the gonadosomatic indexes and fecundity of the bilih fish. Eighty four bilih fish (67 males and 17 females) were divided into two treatment groups of 42 each. The first group was treated with natural feed (phytoplankton) containing 27.89 percent protein and the second group was treated with artificial feed containing 42 percent protein. One sample of two fish each was randoinly taken every two weeks for observation, measurement and analysis. Results of this research revealed that the growth pattern of the bilih fish differs between the inale and female fish under natural feeding but not under artificial feeding conditions. Under natural feeding condition the length and weight of the female and inale bilih fish ranged from 86.00 to 101.75 mm and 5.23 to 8.15 grams, 75.00 to 96.00 mm and 3.12 to 6.35 grams , while under artificial feeding it ranged from 87.00 to 120.05 rnm and 6.01 to 17.01 grams, 78.15 to 108.95 mm and 4.76 to 13.50 grains respectively. Under natural feeding the growth pattern for females and males were negative allometric, positive allometric, whereas under artificial feeding they were isometric. Under natural feeding the female gonads reached its maximum maturity at stage 111 and the male ones at stage IV, whereas under artificial feeding the female and male gonads reached maximum maturity at stage IV. The gonadosomatic indexes of females and males under natural feeding ranged from 1.01 to 9.73 percent and 0.88 to 6.18 percent, and under artificial feeding it ranged from 1.95 to 10.64 percent and 4.18 to 7.26 percent respectively. The total fecundity under artificial feeding were between 4.057 to 11.349 grains. The oocytes development was an asinchronism type with a tendency of partiel spawner. It is generally concluded that artificial feeding with high (42%) protein content promotes growth, gonadal development and fecundity of the bilih fish better than the natural feeding with a lower (27.89%) protein content.
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Judul: Aspek reproduksi ikan bilih, Mystacoleucus padangensis Bleeker dan kemungkinan pembenihannya di Danau Singkarak
Abstrak: Tujuan penelitian adalah I). Mengetahui distribusi ukuran ikan, per­ t mbuhan, umur, hubungan bobot - panjang, dan faktor kondisi. 2). Mengetahui aspek reproduksi meliputi seksualitas, kematangan gonad, indeks gonad somatik, fekunditas, ukuran dan umur pertama kali matang gonad serta siklus reproduksinya. 3 Mengetahui perkembangan oosit, sifat pemijahan, habitat reproduksi, sifat telur dan stadia perkembangannya. 4). Mengetahui fertilitas dan daya tetas telur dari hasil mijahan alami dan buatan, serta mengetahui pertumbuhan dan mortalitas larva. Penelitian dilakukan di Danau Singkarak, meliputi lima stasiun yaitu stasiun I di muara Sungai Sumpur, stasiun II di hulu Sungai Ombilin, stasiun III di muara Sungai Paninggahan, stasiun IV di muara Sungai Sumani dan stasiun V di perairan t ngall danau. Pengambilan contoh ikan bilih dilakukan secara acak sederhana (Wasito, 1993) yaitu SO ekor/minggu/stasiun. Dimulai bulan Agustus 1994 sampai denga bulan Juli 1995. Uji laboratorium dilakukan di Unit Perikanan Perairan Umum Danau Singkarak, yaitu penetasan telur hasil pemijahan alami dan buatan sistim corong di dalam akuarium (25x25x30 cm), dan pemeliharaan larva di dalam akuarium (45x45x35 cm) selama 56 hari yang diberi makanan plankton. Pembuatan preparat histologi ovari dan testis berdasarkan metode Mahoney (1973). Data dianalisis secara deskripsi dan statistika sebagai berikut : Analisis deskripsi dilakukan tehadap telaah morfologi, histologi ovari dan testis berdasarkan kriteria Cassie (dalam Effendie, 1979), Hardjamulia (1987), dan Amstrong et al. (1992). Pengamatan stadia perkembangan telur berdasarkan kriteria Woynarovich dan Horvath (1980), Galaman dan Avtalion (1989). . Analisis parameter pertumbuhan dan umur ikan digunakan model Von Bertalanffy •· paket ELEFAN I (Pauly, 1984). Hubungan bobot dengan panjang, faktor kondisi dan fekunditas dihitung dengan rumus Ricker (1975). Sedangkan indeks gonad somatik memakai rumus Scott (1979). Fertilitas dan daya tetas telur memakai rumus Suseno (1983), dan Kleinbaum et al. (1988). Laju pertumbuhan larva dihitung dengan rumus Weatherly dan Rogers (1978), bobot larva (Zonnevield et al., 1991) dan mortalitas (Effendie, 1979). Dari 13.000 ekor contoh ikan bilih diperoleh 6. 826 ekor (52,51 %) ikan b tina dan 6.174 ekor (47,49 %) ikan jantan. Panjang ikan bilih betina berkisar antara 50 sampai dengan 149 mm dan bobot 1,0 sampai dengan 25 gram. Panjang ikan bilih jantan berkisar antara 50 sampai dengan 119 mm dan bobot 1,0 sampai Panjang asimptotik (L ) ikan bilih adalah 145,81 mm 00 dengan laju pertumbuhan (K) = 0,78 per tahun. Umur teoritis pada saat panjang a dengan nol (t.) = - 0, 13 tahun . Persamaan Von Bertalanffy untuk ikan bilih a ialah : L, = 145,81 (l-eo.1s<1+0,1J>). Ikan bilih betina di stasiun I, III dan V pertumbuhannya bersifat alometrik positif yaitu pertambahan bobot lebih cepat daripada pertambahan panjang. lkan bilih betina di stasiun II dan IV, dan ikan jantan di stasiun I, III, dan IV per­ tumbuhannya bersifat alometrik negatif yaitu pertambahan panjang lebih cepat daripada pertambahan bobot. Sedangkan ikan jantan di stasiun II clan V pertumbuhannya ersifat isometrik yaitu pertambahan bobot seimbang dengan pertambahan panjang.
Keyword: Ikan Bilih, Perkembangan Ovari, Histologi

Judul: Penerapan teknik watermarking untuk penandaan hak cipta pada peta vektor dengan format DXF
Abstrak: Drawing Interchange Format (DXF) is one of the general file in the field of the vector image commonly used for making maps. The DXF format is a tagged data representation of all the information contained in an AutoCAD drawing (DWG) file. Tagged data means that each data element in the watermark is preceded by an integer number called the group code. The study was carried out because there is still no tools of labeling the copyright on digital mapping using DXF file. This study aims to generate an application for copyright labeling on vector map with DXF format that can be applied to any types of spatial objects in the map. The technique used is changing the code inside the vector image. The insertion of the watermark is done by utilizing ENTITIES section by multiplying objects for sets of binary values. The results showed that the image after the watermarking insertion process is the same as the original vector image. Embedded watermark is resistant to rotation and scaling, however it has the possibility of one-third to be broken in the attack on specific object. This study has successfully implemented watermarking technique for copyright labeling on the vector map with DXF format.
Keyword: Drawing Interchange Format, Robust Watermark, Tagged Data, Vector Image, Watermarking