Utilization of rotifers as natural feed in the rearing of saline nile tilapia (Oreochromis niloticus) larvae

After the yolk sac of fish larvae is absorbed, they will utilize external food sources such as natural phytoplankton and zooplankton. Specifically, one of the zooplankton species used is the small-sized rotifer Brachionus sp., which matches the mouth opening of the larvae. The purpose of the experiment was to examine the effects of providing live rotifer in combination with artificial feed on the survival rate and growth of Nile tilapia (Oreochromis niloticus) larvae in high salinity conditions. The Nile tilapia larvae used in the experiment were the offspring of Red Nifi strain breeders raised in freshwater and still containing yolk sacs. Feeding commenced after the yolk sacs were absorbed, and the salinity was gradually increased to 25-30 ppt. The larvae were fed with rotifers for seven days (P-1), 14 days (P-2), and then continued with another type of artificial feed. There was also a control group that only received artificial feed without rotifers. The stocking density of the fish larvae was 25 individuals per liter, and the total water volume used was 15 liters. The rotifer dose was maintained at 10-20 individuals per milliliter of water per day during the 4-week rearing period. The results showed that providing rotifers in water salinity between 10-15 ppt during the first seven days resulted in a survival rate of > 80%, whereas the control group achieved > 90% survival. However, the survival rate of the larvae started to decline from the second seven-day period with the increase in salinity between 15-25 ppt, and it continued to decrease to < 60% until the fourth week for all treatments

Pengaruh ekstrak alkaloid daun tapak dara (Catharanthus aspergillus roseus (L) (Don) terhadap pertumbuhan Aspergillus flavus (Link.

AGUSTIEN NARYANINGSIEI J 201 91 562. Pengaruh ekstrak alkaloid daun tapak dara (Catharanthus aspergillus roseus (L) (Don) terhadap pertumbuhan Aspergillus flavus Link. Salah satu tanaman semak yaitu tapak dara (Catharanthus roseus L.) mengandung zat obat alami yang berkhasiat untuk mengobati penyakit diabetes melitus, tekanan darah tinggi (hipertensi), pendarahan, kanker dan lain-lain. Zat berkhasiat itu diantaranya leurosin, katarantia, vindolin, vindolinin, tetrahidroalstonin yang dapat menurunkan kadar gula dalam darah. Selain itu jugs. terdapat zat anti kanker seperti vinblaStin, vinkristin, vinkadiolin, leurosidin (Anonirn, 1995). Untuk itu perlu diteliti pengaruh ekstrak alkaloid daun tapak dara (C. roseus L.) terhadap pertumbuhan kapang A flavus yang diketahui dapat mengakibatkan penyakit kanker. Penelitian ini bertujuan untuk mengetahui pengaruh ekstrak alkaloid daun tapak dara (C. roseus) terhadap pertumbuhan kapang A flavus dan untuk mengetahui konsentrasi ekstrak alkaloid daun tapak dara yang paling besar pengaruhnya terhadap pertumbuhan kapang A_ flavus. Ekstraksi alkaloid daun tapak dam dilakukan dengan metode ekstraksi Sivakumaran dan Gopinath (1976) dan kapang A flavus diperoleh dui hasil isolasi kapang tanali. Perlakuan antara ekstrak alkaloid daun .tapak dara dengan kapang A flavys menggunakan Rancangan Acak .Lengkap (RAL). Parameter yang diukur adalah berat kering kapang A flavus setelah diinkubasi selama 7 Bari. Data yang diperoleh dianalisis dengan analisis sidik ragam dilanjutkan dengan uji Beda Nyata Jujur (BNJ) dan analisis regresi-korelasi. Hasil penelitian menunjukkan bahwa ekstrak alkaloid daun tapak dara dapat menghambat pertumbuhan kapang A. flavus dan konsentrasi ekstrak alkaloid daun tapak dara yang paling besar penganih hambatannya terhadap pertumbuhan kapang A flavus pada konsentrasi ekstrak alkaloid 0,6% (b/v)

KEEFEKTIFAN Bacillus cereus (Frankland and Frankland) ATCC 11778 (BAKTERI GRAM POSITIF) DAN Pseudomonas aeruginosa( Schroeter) ATCC 27853 (BAKTERI GRAM NEGATIF) SEBAGAI BIOAKUMULATOR KADMIUM

Heavy metal in the industrial waste can influence the quality of water environment. The problem related is accumulation of heavy metals in food chain and prolong existence in environment. Some physical and chemical techniques have been conducted by many authors to decrease concentration of heavy metals in waters,. however the results are still higher than that suggested by government. Therefore a method called bioremidiation may become an alternative in decreasing concentration of heavy metals in waters. This study was aimed to analyze ability of bacterias Bacillus cereus and Pseudomonas aeruginosa to accumulate cadmium in the waters. Both of the bacteria were growth on Zobell medium that contain 0.3 ppm of cadmium. The incubation was done on room temperature, for 24 hours at pH 7. Dry weight and cadmium content (estimated by the AAS) were used to determine the bacteria growth. The result showed that accelerations of the accumulation cadmium was 76.34 %/24 hour (P. aeruginosa) and 55.88 %/24 hour (B. cereus) or the accelerations of the accumulation cadmium by P. aeruginosa 1.4 greater than B. cereus. Its concluded that P. aeruginosa was more effectively to accumulate the cadmium of the medium. Limbah yang mengandung logam berat dari proses industri yang tidak diolah akan berakibat buruk terhadap lingkungan. Problem khusus yang berhubungan dengan logam berat dalam lingkungan adalah akumulasi dalam rantai makanan dan keberadaan yang terus menerus di lingkungan. Upaya penazaganan pencemaran logam berat baik secara fisik maupun kimia telah banyak dilakukan, namun temyata hasil pengolahan tersebut masih di atas ambang baku mum yang ditetapkan oleh pemerintah. Salah satu metode alternatif yang dikembanglcan untuk mengatasi pencemaran logam berat adalah cara biologi dengan menggunakan bakteri yang dikenal sebagai bioremidiasi. Bakteri yang digunakan dalam penelitian ini adalah cereus (bakteri Gram positif) dan Pseudomonas aeruginosa (balcteri Gram negatif). Kedua balcteri ditumbuhlcan pada medium Zobell yang mengandung Cd dengan konsentrasi 0.3 ppm pada pH 7 dan diinlcubasi pada suhu kamar selama 24 jam. Pertumbuhan dan akumulasi Cd oleh bakteri diamati setiap 3 jam sekali. Pertumbuhan bakteri diamati dengan mengukur berat kering dan akumulasi Cd ditentukan dengan AAS. Hasil penelitian menunjukkan bahwa laju akumulasi Cd oleh aeruginosa sebesar 76.34 % per 24 jam dan B. cereus sebesar 55.88 % per 24 jam atau dapat dikatakan laju akutnulasi Cd oleh P.aeruginosa 1,4 kali lebih besar dibanding B. cereus. Kesimpulannya adalah P. aeruginosa lebih efektif dalam mengakumulasi Cd dibanding B. cereus

Inkubasi suhu selama tahap embrio-larva untuk menginduksi pembalikan jenis kelamin ikan nila strain Red NIFI

This research aims to achieve male sex reversal in Nile Tilapia (Orechromis niloticus) of the red NIFI strain through high-temperature incubation during the embryonic or pre-swimming larval phase. Larvae resulting from the natural mating of red NIFI strain broodstock were incubated under temperature treatments of 31oC, 33oC, 35oC, and a control group (&lt;30oC), each with three replicates. Temperature regulation was facilitated using a heater.  During the initial 3 hours of incubation, the heater was turned off for 6 hours, followed by another 3 hours of incubation with the heater on. This pattern was repeated daily until the larvae began to swim. The treated larvae were then reared for 90 days. Thirty specimens from each replicate were identified for gender using the squash acetocarmine method. The study results indicated that temperature differences significantly influenced (p&lt;0.05) the sex ratio of Nile tilapia in the red NIFI strain. The highest proportion of males was achieved at 33oC, at 73.33%, and 35oC, at 64.43%. There were no significant differences (p&gt;0.05) in fry survival rates at 7 days and after 90 days of rearing.Penelitian ini bertujuan untuk melakukan pengalihan kelamin jantan ikan nila (Orechromis niloticus) dari galur Red NIFI melalui inkubasi pada suhu tinggi selama fase embrio atau fase larva belum berenang. Larva yang dihasilkan dari perkawinan alami induk galur Red NIFI diinkubasi dengan perlakuan suhu 31oC, 33oC, 35oC, dan kontrol (&lt;30oC), masing-masing dengan tiga ulangan. Inkubasi suhu dilakukan menggunakan alat water-heater. Selama 3 jam awal inkubasi, water-heater dimatikan selama 6 jam, diikuti oleh 3 jam inkubasi lagi dengan water-heater dinyalakan. Pola ini diulang setiap hari sampai larva mulai berenang. kemudian dipelihara selama 90 hari. Tiga puluh ekor sampel benih dari masing-masing ulangan diidentifikasi jenis kelaminnya menggunakan metode squash-acetocarmine. Hasil penelitian menunjukkan bahwa perbedaan suhu secara signifikan memengaruhi (p&lt;0,05) rasio jenis kelamin ikan nila (O. niloticus) galur Red NIFI. Proporsi kelamin jantan tertinggi dihasilkan pada suhu 33oC, sebesar 73,33%, dan 35oC, sebesar 64,43%. Tidak ada perbedaan signifikan (p&gt;0,05) dalam tingkat kelangsungan hidup benih pada 7 hari dan setelah 90 hari pemeliharaan

Incubating red NIFI strain of tilapia eggs in a closed-water recirculation system with varied salinity levels

This research aims to determine the impact of varying salinities on the hatching of red NIFI tilapia eggs in a closed-water recirculation system incubator. The eggs were hatched at salinities of zero ppt, one ppt, five ppt, and ten ppt, with three replications per treatment. The stocking density for each replication was set at 1,750 eggs per liter. After a six-day incubation period, the resulting larvae were reared under the same salinity conditions for four weeks, with a stocking density of 1,000 individuals per cubic meter. The hatching rate of eggs recorded for the zero ppt salinity treatment was 74%. There was no significant difference between the zero ppt, one ppt (73%), and five ppt (69%) salinity treatments, while the ten ppt (24%) yielded significantly different hatching rates of eggs results (p<0.05). The highest survival rate of reared larvae was achieved in zero ppt salinity treatment, reaching 75%. Salinities of one ppt, five ppt, and ten ppt yielded larvae survival rates of 70%, 55%, and 49%, with statistical significance (p<0.05). Egg hatching in an incubator with a closed water recirculation system at low salinity levels can be considered an initial adaptation step in brackish water tilapia seed production

From sea to solution: A review of green extraction approaches for unlocking the potential of brown algae

The global production of commercial aquatic plants, which includes macroalgae, has reached 31.2 million. To unlock the vast potential of brown algae as abundant sources of diverse bioactive compounds, efficient extraction methods aligned with sustainability goals are crucial. This comprehensive review delves into the paradigm shift towards green extraction techniques tailored for brown algae. The bioactive compounds present in brown algae hold substantial industrial value, extending across pharmaceuticals, cosmetics, food, and agriculture. However, conventional methods like solvent extraction and hydro distillation face challenges related to environmental impact and efficiency. The review emphasizes the principles of green extraction and thoroughly examines advanced methods such as supercritical fluid extraction (SFE), microwave-assisted extraction (MAE), and subcritical water extraction (SWE), providing insights into their mechanisms, advantages, and applications. This review gathers information from articles published in English between 2004 and 2023. While recognizing the obstacles in implementing green methods, the review also outlines future directions for sustainable extraction of bioactive compounds from brown algae. By embracing eco-friendly techniques, both researchers and industries can effectively harness bioactive compounds while contributing to environmental well-being