Rahma Aulia

Scopus Publications

Hatching and survival rate of milkfish (Chanos chanos) larvae treated with nanosilver
Lisa Ruliaty, Indrian Rizka Amalia, Abidin Nur, Rahma Aulia, and Joko Sumarwan
EDP Sciences
This study was aimed to know the effect of hatching and survival rate of milkfish larvae (Chanos chanos) treated with nanosilver. Three concentrations of nanosilver such as 0.25 ppm, 0.5 ppm and 0.75 ppm were applied to culture media at least an hour before stocking. Newly hatched larvae were stocked at the density of 50 pcs l-1, and it was reared for 25 days in 5 m3 of concrete tank. Result of the study found that no significant effect (p>0.05) of the treatments given on hatching rate and survival of milkfish larvae. However, larvae treated with nanosilver tend to gain higher hatching rate (65.5±4.1 86.6±19.0%) compared to control one (65.3±7.2%). Further, larvae survival it was ranged of 24.2±0.9-26.3±0.1% by the end of the trial. Nanosilver treatments has potential to reduce the total bacteria and Vibrio concentration into the media and need further study primarily on dosage and frequency used.

Incubating red NIFI strain of tilapia eggs in a closed-water recirculation system with varied salinity levels
Rahma Aulia, Lisa Ruliaty, Agustien Naryaningsih, Zaenal Arifin, and Mohamad Soleh
EDP Sciences
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.

Application of fermented bran and probiotics to enhance mass-scale production of Phronima sp. in the pond
Lisa Ruliaty, Indrian Rizka Amalia, Rahma Aulia, Abidin Nur, Siska Apriliyani, and Kaemudin
EDP Sciences
This study aimed to evaluate the efficacy of utilizing probiotics and organic matter as nutrients for Phronima sp. mass cultures in ponds. Culture media, which had water depths of 40 cm was added to the pond plots (35×30×0.4 m), then sterilized and neutralized. Organic fertilizer (70 kg/1000 m2) was spread, and after 3 days the inorganic fertilizer was spread in the form of ZA (20 ppm), TSP (5 ppm), and NPK (5 ppm). Rice bran, a by-product of rice production, was fermented with molasses for a week, with a dosage of 1:0.25. Fermented bran mixed with probiotics (ratio of 1:1) was used as daily feed. Phronima sp. was spread with a density of 137 individuals/m2. The population density was monitored weekly. The test results showed that the growth pattern of Phronima sp. formed a sigmoid curve consisting of the lag phase, specific growth rate, population peak, and death phase. There was a significant population increase from the fourth to the seventh week, with a peak population density in the seventh week, reaching a density of 87,300 ± 6,526 individuals/m2. In the eighth week, the population density drastically decreased to only 10% of the peak.

Enhancement growth of plantlet Gracilaria sp. with additional fermented fertilizer
A L Nurhayati, D Permana, R Aulia, and Nurhidayat
IOP Publishing
Abstract The purpose of this research is to know the influence of additional fermented fertilizer to the growth of plantlet Gracilaria sp. during acclimatization stage. The comparison of composition fermented fertilizer from Leucaena leucocephala leaves : Moringa oleifera leaves which used were 75%:25%, 50%:50%, 25%:75% and control without additional fermented fertilizer. The best plantlet growth after seven weeks testing, found in comparison 25%:75% with enhancement plantlet growth up till 32,4%, followed with comparison 50%:50% with enhancement plantlet growth up till 27,1%, the last with comparison 75%:25% and control which both show enhancement plantlet growth up till 13,5%. Based on this result, we carried out further testing with comparison 20%:80%, 15%:85%, 10%:90% and 5%:95% but the plantlet growth result only as much 12,67%; 26,67%; 24,67% and -0,09% so we recommend to use combination fermented fertilizer from Leucaena leucocephala leaves : Moringa oleifera leaves with comparison 25%:75% in acclimatization step since it’s not only increase the weight but also the length and number of shoots. However, it’s necessary to do further testing using other fertilizer raws to get better plantlet growth result.

Different Nitrogen Sources to Improve the Quality of Spirulina platensis Culture in Mass Scale
L Ruliaty, I R Amalia, R I Sari, and R Aulia
IOP Publishing
Abstract The research aimed to determine the effect of adding different sources of nitrogen to mass culture of Spirulina platensis. Materials needed for this test was culture media volume 1000 m3, fertilizer were SP-36 (40 ppm), ZA (10 ppm), EDTA (5 ppm) dan FeCl3 (1 ppm), Vitamin B-12 (0,001 ppm) and initial density of S. platensis was 10x103 sinusoid/ml. The test was carried out in two steps, firstly was the addition of nitrogen source from urea with doses of 80 ppm, 150 ppm and 200 ppm. Secondly, concurrent use of the best urea concentration from first treatment and potassium nitrate addition with doses of 50 ppm, 100 ppm and 150 ppm. Spirulina platensis was cultured on mass scale for 5 days until harvest. The first test showed that the dose of urea 80 ppm gave the highest growth rate (1,15 sinusoid/day) and the fastest generation time (0,60 hours) compared to doses of 150 ppm and 200 ppm. Protein content of Spirulina platensis added with 80 ppm of urea was also the highest (58,04%) compared to 150 ppm and 200 ppm. The results from second test showed concurrent use of urea 80 ppm and potassium nitrate 100 ppm to Spirulina platensis culture gave the highest growth rate (0,45 sinusoid/day) and the fastest generation time (1,54 hours) compared to those which added with 150 ppm and 50 ppm of potassium nitrate. Protein content of S. platensis with concurrent addition of urea 80 ppm and potassium nitrate 100 ppm was also the highest at 67,30%, compared to 150 ppm and 50 ppm.

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