Judul: Seleksi Bakteri Probiotik dari Saluran Pencernaan Untuk Meningkatkan Kinerja Pertumbuhan Ikan Jelawat Leptobarbus hoevent Blkr:
Abstrak: The effect of probiotics isolated from jelawat fish gut Leptobarbus hoeveni supplemented into the diet on enzym activities, growth performance of jelawat fish and digestibility was investigated. A triplicate experiment was conducted using 6-7 g jelawat fish. Each fish was fed on the diet supplemented with either probiotics produce amylase (U4), produce lypase (S1), produce protease (U12), produce protease, lypase and amylase (U7) or control (no supplementation of probiotics). Regardless of the strain, the application of probiotics significantly increased the bacteria population in the fish gut, thereby digestibility and protein retention, food conversion ratio and growth of fish significantly improved. On the other hand, fish fed on the diet supplemented with U4 probiotics had the best growth performance. Therefore, U4 is the best probiotics isolated from the jelawat fish gut to use as a supplementary diet for jelawat fish
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Judul: Kerentanan Ikan Jelawat Leptobarbus hoevenii Blkr Terhadap Infeksi Bakteri Patogen
Abstrak: Pengembangan industri akuakultur memerlukan diversifikasi melalui komersialisasi dengan cara domestikasi spesies baru, terutama terhadap jenis ikan yang bernilai ekonomis penting. Hal ini sangat didukung oleh kekayaan fauna ikan perairan umum Indonesia yang memiliki keanekaragaman hayati yang sangat tinggi, di mana salah satu jenis ikan yang telah didomestikasi tersebut adalah ikan jelawat Leptobarbus hoevenii Blkr (BALITAN 1988, diacu dalam Asyari & Gaffar 1993). Jelawat merupakan jenis ikan liar yang hidup di perairan sungai dan rawa, ikan ini mempunyai nilai ekonomis tinggi di Indonesia, terutama Sumatera dan Kalimantan (Handoyo et al. 2010). Unit Pembenihan Ikan Sentral (UPIS) Provinsi Kalimantan Barat (Kalbar), telah berhasil melakukan pembenihan ikan jelawat dengan teknik kawin suntik sehingga untuk mendapatkan benih secara massal, teknik perawatan larva dan post larva sudah berjalan dengan lancar (Sunarno et al. 1988; Kristanto et al. 1994). Dewasa ini Pemerintah Daerah melalui Dinas Perikanan dan Kelautan Provinsi Kalbar telah menetapkan program intensifikasi usaha budidaya ikan air tawar salah satunya termasuk ikan jelawat. Hal tersebut didukung oleh potensi alam bagi pengembangan budidaya air tawar, meliputi kolam 2.538,03 ha dan keramba 55,79 ha, dengan jumlah produksi jelawat sebesar 100,80 ton untuk kolam dan keramba 846,45 ton (DKP Kalbar 2008). Penetapan program ini diharapkan dapat melestarikan ikan asli daerah dan meningkatkan ekonomi masyarakat setempat. Intensifikasi budidaya jelawat dengan padat tebar tinggi dan pemberian pakan optimal, memberikan peluang berkembangnya bibit penyakit, salah satunya yang disebabkan oleh bakteri. Sampai sekarang belum ada data mengenai serangan penyakit bakterial yang mematikan dan merugikan usaha budi daya ikan jelawat, namun dengan adanya intensifikasi budi daya maka peluang untuk berkembangnya penyakit merupakan suatu konsekuensi yang tidak dapat dihindari. Bertolak dari hal tersebut maka penelitian ini dilakukan untuk menguji kerentanan ikan jelawat terhadap infeksi beberapa bakteri patogen melalui metode penginfeksian yang berbeda, serta mempelajari patogenitas bakteri pada jaringan dan organ tubuh. Penelitian ini dilaksanakan selama 5 bulan, mulai dari bulan Februari sampai dengan bulan Juli 2010, di Laboratorium Kesehatan Ikan, Departemen Budidaya Perairan, Fakultas Perikanan dan Ilmu Kelautan IPB. Tahapan penelitian meliputi 3 tahapan percobaan yaitu 1) pengujian kerentanan ikan jelawat terhadap infeksi bakteri patogen; 2) distribusi bakteri patogen di dalam tubuh; serta 3) perubahan gambaran darah, makroskopis dan mikroskopis akibat infeksi bakteri patogen....dst
Keyword: susceptibility, jelawat, pathogenic bacterial infections

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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