Pertumbuhan Dan Kelangsungan Hidup Ikan Hias Koridoras (Corydoras Aeneus Gill 1858) Pada Budi Daya Kepadatan Tinggi [the Growth and Survival Rate of Ornamental Fish Bronze Corydoras (Corydoras Aeneus Gill 1858) in High Density Cultured]

Penelitian ini bertujuan untuk menganalisis pengaruh kepadatan tinggi pada budi daya ikan hias koridoras (Corydoras aeneus) terhadap pertumbuhan dan kelangsungan hidup. Ikan yang digunakan adalah ikan hias koridoras berbobot 0,210,23 gram dan panjang baku 1,84-1,90 cm yang dipelihara pada akuarium berdimensi 20 cm x 20 cm x 20 cm, volume air enam liter per akuarium. Penelitian ini menggunakan rancangan acak lengkap dengan perlakuan padat tebar 20 ekor liter-1 (A) dan padat tebar 25 ekor liter-1 (B), tiga kali ulangan. Ikan dipelihara selama 35 hari dan diberi pakan pelet ko-mersial setiap hari pukul 08.00 dan pukul 16.00, pakan diberikan sebanyak 5% dari bobot ikan. Hasil penelitian menun-jukkan bahwa pertumbuhan bobot mutlak dan laju pertumbuhan bobot harian pada kedua perlakuan tidak berbeda nya-ta, namun pertumbuhan panjang mutlak dan laju pertumbuhan panjang harian perlakuan B lebih tinggi hampir dua kali lipat dibanding perlakuan A. Pemanfataan pakan pada perlakuan B lebih efisien. Nilai kelangsungan hidup perlakuan A (92,78%) lebih tinggi daripada perlakuan B (86,89%). Kualitas air selama pemeliharaan yaitu suhu, pH, oksigen terla-rut, amonia nitrogen total, nitrit, dan nitrat pada kedua perlakuan masih dalam batas toleransi untuk budi daya ikan

Binary Vector Construction of Kappa(κ)-carrageenase Gene and Transformation to Agrobacterium Tumefaciens as Mediator for Seaweed Transgenic Generation

Increasing of kappa (κ)-carrageenan content in Kappaphycus alvarezii seaweed is potentially be achieved by applying transgenesis technology. This study was performed to obtain a construction of κ-Carrageenase gene and Agrobacterium tumefaciens to carry those construction genes. The κ-Carrageenase (κ-Car) gene was involved in κ-carrageenan biosynthesis. The κ-Car gene sequence was ligated between the 35S CaMV promoter and tNos terminator sequences to generate pMSH/κ-Car expression vector. Transformation of pMSH/κ-Car plasmid to Escherichia coli was performed by heat-shock method, and to Agrobacterium tumefaciens by tri-parental mating method. The results showed that several colonies of E. coli and A. tumefaciens grew in the selective culture mediums containing antibiotic. PCR analysis using primers 35S-Forward and tNos-Reverse with DNA template from those bacterial colonies resulted DNA fragment of about 2,000 bp, the same as the total length of 35S CaMV promoter, κ-Car gene and tNos terminator sequences. Therefore, the construction of pMSH/κ-Car gene was succeeded and a colony of A. tumefaciens transformant carrying pMSH/κ-Car plasmid was successfully produced

Evaluation of Microbial Floc and Microalgae Spirulina Platensis Combination for Juvenile Cobia Rachycentron Canadum Diets on Growth and Physiological Responses After Immersion in Freshwater

In marine aquaculture, immersing marine fish species in fresh water can remove ectoparasite that adhere to all over the fish body. This study aimed to evaluate the impacts of combining microbial floc and microalgae Spirulina platensis in juvenile cobia diet on growth performance and stress responses after immersion in aerated fresh water for 15 minutes. The fishes were reared in concrete tanks for 40 days before collecting data on their growth performance. The stress response was determined by mea-suring both glucose and cortisol levels before (0 h) and after (1, 2, 4, 6, 24 hours) immersion. The fish-es fed on the 15% of combining microbial flock and microalgae Spirulina platensis diet showed the highest growth rate with the lowest feed conversion ratio compared to other treatments. The cortisol level of juvenile cobia in both the 15% and 30% combination of microbial floc and microalgae Spiru-lina platensis treatments did not increase during the first hour following the immersion compared to the control treatment. The glucose level also increased after one hour immersion in freshwater of all treatments. This indicated that feeding juvenile cobia on microbial flocs and microalgae diets had a retarding effect on the physiological responses (cortisol and glucose) after immersion in fresh water

Hubungan antara Kelimpahan Fitoplankton dengan Parameter Fisik-kimiawi Perairan di Teluk Jakarta

Fitoplankton mempunyai peranan yang sangat penting di dalam suatu perairan, selain sebagai dasar dari rantai pakan (primary producer) juga merupakan salah satu parameter tingkat kesuburan suatu perairan. Tujuan penelitian ini adalah mengetahui struktur komunitas dan kelimpahan fitoplankton di Perairan Teluk Jakarta serta mempelajari hubungan antara kelimpahan fitoplankton dengan beberapa parameter fisik-kimiawi perairan. Penelitian dilaksanakan pada bulan Agustus, September, dan November 2009 di Teluk Jakarta, pada 9 (sembilan) stasiun dengan metode pengendapan. Hasil penelitian menunjukkan bahwa ditemukan 47 genera dari 4 (empat) kelas fitoplankton yang terdiri atas 26 genera kelas Bacillariophyceae, 8 genera kelas Chlorophyceae, 7 genera kelas Cyanophyceae, dan 6 genera kelas Dinophyceae. Kelimpahan yang diperoleh berkisar antara 194.000 - 20.132.143 sel/l. Kisaran nilai indeks-indeks biologi yang ditemukan adalah indeks keanekaragaman (H') = 0,6148 - 2,2375, indeks keseragaman (E) = 0,2397 - 0,8614, dan indeks dominansi (D) = 0,1316 - 0,7498. Parameter fisika-kimia perairan berturut-turut adalah nitrat 0,0072 - 0828 mg/l, ortofosfat 0,0114 - 0,3480 mg/l, silika 0,2787 - 5,9946 mg/l, pH 7,59 - 8,73, suhu 26,40 - 31,80oC, dan salinitas 28,00 - 33,00. Hasil analisis regresi linear berganda ditemukan bahwa terdapat keterkaitan yang sangat erat antara parameter fisika-kimia perairan dengan kelimpahan fitoplankton (R2 = 0,739) dengan persamaan regresi Y = - 53190202 + 330084 suhu - 199740 salinitas + 6103042 pH - 10442291 nitrat - 3275245 ortofosfat + 2545042 silika

Peningkatan Kualitas Nutrisi Tepung Daun Lamtoro Sebagai Pakan Ikan Dengan Penambahan Ekstrak Enzim Cairan Rumen Domba [Improvement Nutrition Value of Leucaena Leaf Meal as Fish Feed with Addition of Sheep Rumen Fluid Enzyme]

The aim of this experiment is to evaluate the nutrient quality of leucaena leaf meal (LLM) with addition of sheep rumen fluid enzyme for nile tilapia feed and incubated in vitro either for 2 or 24 hours. This experiment was arranged in a completely randomized design with 6 treatments and 3 replications. Those treatments were enzyme levels of 0, 20, 40, 60, 80, and 100 ml/ kg LLM. Results showed that nutrient quality of LLM with addition of sheep rumen fluid enzyme that incubated for 24 hours had the best result compared to that incubated for 2 hours. This finding significantly affected (PO.05) on the increase of sugar release (76.97%), soluble glucose (21.27%) and soluble protein (37.7%). It is concluded that sheep rumen fluid enzyme has a great potential for improving nutritional quality of leucaena leaf meal of fish feed