Morphological Characterization and DNA Barcoding of Duckweed Species in Saudi Arabia

Duckweeds, or Lemnaceae, are widespread aquatic plants. Morphology-based identification of duckweed species is difficult because of their structural complexity. Hence, molecular tools provide significant advantages for characterizing and selecting species or clones for sustainable commercial use. In this study, we collected and characterized ten duckweed isolates from nine different regions in Saudi Arabia (SA). Based on the morphological characterization and phylogenetic analysis of intergenic spacer sequences of chloroplast DNA using six barcoding markers, the clones were classified into three genera, represented by seven species: Lemna gibba L., Lemna minor L., Lemna japonica Landolt, Lemna aequinoctialis Welw., Lemna perpusilla Torr., Spirodela polyryiza (L.) Schleid., and Landoltia punctate G. Mey. Lemna gibba was revealed to be a distinct dominant duckweed species in many regions of SA. Five barcoding markers showed that L. gibba, L. minor, and L. punctata were the most widely distributed species in the country. However, L. punctata, L. perpusilla, and S. polyryiza were the dominant species in the Al-Qassim, Madinah-1, and Madinah-2 regions, respectively. Moreover, the morphological traits revealed variations for these clones, relative to other studied duckweed clones. According to the results obtained in this study, three out of six plastid markers (trnH-psbA, matK, and atpF-atpH) helped to identify the dominant duckweed species in Saudi Arabia. Further evaluation based on adaptability, molecular genetic studies, and functional genomics is needed for these species to be used at the commercial level in Saudi Arabia.

Use of minute duckweed (Lemna perpusilla) for supplemental feed in catfish (Clarias sp.) culture: determination of the optimal proportion using powersim simulation

Catfish farming is very profitable because the fish is easy to rear and can be harvested quickly. However, the cost of feed as the most significant component in production costs is currently getting higher. The availability and utilization of alternative feed is an urgent solution in creating sustainable catfish farming. This research was carried out during December 2020 – January 2021 in the Research Center for Limnology, Cibinong, Indonesia, which aims to determine the optimal proportion of minute duckweed (Lemna perpusilla) biomass added as feed supplemental to obtain an optimum growth of catfish fingerlings (Clarias sp.). Catfish were reared for 63 days in nine aquariums with a density of 25 fish per aquarium. The commercial pellet given in the control aquarium was 100% pellet portion (5% of the total fish weight), while in the treatment aquariums were 60% and 40% of the total fish weight. As compensation, fresh duckweed (L. perpusilla) was provided ad libitum. Fish were sampled twice to measure their weight and body length. This study showed that the proportion of duckweed as much as 40% as a supplement for commercial pellets could produce optimal catfish growth.

Effect of duckweed meal dietary inclusion on growth performance and survival of African catfish fingerlings

Currently, the use of unconventional food sources in the inclusion of fish diets is cause of great interest. The growth performance of African catfish (Clarias gariepinus) was evaluated, with the inclusion of duckweed meal (Lemna perpusilla) in four levels (0, 6, 12 and 18 %) in the diet. African catfish with an average weight of 1.27 ± 0.03 g, were distributed in a completely randomized design, with 16 experimental cages (four replicates/treatment). The fingerlings were fed for 48 days of experimentation. An analysis of variance and a Duncan´s test were performed. No significant differences were found (p< 0.05) for the first two levels evaluated, but with the rest there were differences, as the percentage of inclusion of the duckweed meal in the ration increased. Final weight was decreasing, as well as absolute growth rate, increase in daily weight, feed conversion ratio and food efficiency. Survival throughout the experiment was between 72 y 65 % in all treatments. The inclusion of duckweed meal in the diet did not affect the parameters of water quality. It was concluded that the L. perpusillase meal can be included up to 12 % in diets for African catfish fingerlings, without affecting the growth performance.

The Effectiveness of the Use of Aquatic Plants (Lemna perpusilla, Landoltia punctata and Azolla pinnata) in the Phytoremediation Process of Catfish Aquaculture Wastewater

Aims: The purpose of this study was to determine aquatic plants (Lemna perpusilla, Landoltila punctata and Azolla pinnata) that have the most effective ability as phytoremediation agents for catfish cultivation wastewater. Study Design: This research was conducted by an experimental method, with a Completely Randomized Design (CRD) consisting of three treatments and four replications. Place and Duration of Study: This research is located at the Wet Laboratory (Ciparanje) of the Faculty of Fisheries and Marine Sciences, Padjadjaran University. Water quality testing is carried out at the Water Resources Laboratory of the Faculty of Fisheries and Marine Sciences. Research was carried out on 20 July-24 September 2019. Methodology: The test wastewater was collected from catfish pond culture and put into twelve aquarium with a volume of 8 litre. Physical and chemical parameters observed include BOD5, dissolved oxygen, CO2 acidity, temperature, nitrate, and phosphate. Results: Lemna perpusilla, Landoltia punctata and Azolla pinnata were able to improve the quality of catfish culture wastewater such as increasing the concentration of dissolved oxygen (DO) and pH, and reducingBOD5, CO2, nitrate and phosphate. Lemna perpusilla was able to reduce the concentration of BOD5, CO2,carbondioxide, nitrate and phosphate from catfish cultivation wastewater by75%; 77.7%; 23.4%; 44.2%, respectively, during the phytoremediation process, and Landoltia punctata was able to reduce the concentrations same parameters by 52%; 68.3%; 17.8%; 18.3% and Azolla pinnata by 41%; 84%; 15.3% and 28.4%. Conclusion: Lemnaper pusillamay improve the quality of catfish culture wastewater better than Landoltia punctata and Azolla pinnata. Lemna perpusilla can be recommended as phytoremediation agents catfish cultivation wastewater to remediate organic matter before being discharged directly into water bodies.

Short Communication: Diversity of duckweed (Araceae-Lemnoideae), morphological characteristics and its potentials as food sources for herbivorous fishes in West Java, Indonesia

Andriani Y, Irawan B, Iskandar, Zidni I, Partasasmita R. 2019. Diversity of duckweed (Araceae-Lemnoideae), morphological characteristics and its potentials as food sources for herbivorous fishes in West Java, Indonesia. Biodiversitas 20: 1617-1623. Duckweed is aquatic plant potential as a source of protein to feed herbivorous fish. The purpose of this study was to explore the diversity of duckweed species occurred in several areas in West Java. The exploration was done by collecting duckweed (Araceae) from water bodies such as lakes and ponds located in the fishery center in Garut, Bandung, Sumedang and Tasikmalaya Districts. The sample was identified using stereomicroscope to know the morphological characteristic. Characteristics being observed included root tip and sheath as well as the morphological frond characteristics. The result of study showed there were three species of duckweed recorded at the studied areas in West Java, namely Spirodela polyrhiza (L.) Schleid, Lemna perpusilla Torr. and Lemna gibba L. The three duckweed species can be distinguished based on its morphological characteristics, such as the number of roots, types of root tip, root sheath, symmetric-frond, gibbous-frond, and nerve-frond. In the studied areas, duckweed plants were found in ponds, stagnant water, and rice fields. Duckweeds can be used as a source of protein in fish feed as they have high protein content and complete amino acids.

The application of phytoremediation Lemna perpusilla to increase the production performance of Nile tilapia Oreochromis niloticus in a recirculation system

<p align="center"><strong>ABSTRACT</strong></p><p>This study aimed to evaluate the production performance and physiological of Nile tilapia using <em>Lemna perpusilla </em>as a phytoremediator in a recirculation system. A completely randomized design with two treatments and three replications was applied. The treatments were Nile tilapia cultured with <em>L. perpusilla </em>(TL)<em> </em>and without <em>L. perpusilla </em>(L). The experimental fish in this study was the juvenile of Nile tilapia with a body length of 9.98 ± 0.08 cm and an average weight of 36.27 ± 1.07 g. The stocking density was 46 fish/pond and the container size was 275×100×60 cm³ and was separated in two areas using a fiber separator screen of 55.9% area for fish culture and 44.1% for <em>L. perpusilla</em>. The Nile tilapias were reared for 60 days, fed with commercial diet and fresh <em>L. Perpusilla </em>with amount 2% and 1% of biomass, respectively. They were fed three times a day with fresh <em>L. perpusilla </em>at noon and commercial diet in the morning and afternoon. The results showed that the Nile tilapia reared with <em>L. perpusilla</em> phytoremediation had normal physiological condition and production performance.<strong> </strong>The predominances of this system were lower feed conversion ratio value, more optimal values of feeding efficiency, and higher coefficient of weight uniformity.</p><p> </p><p>Keywords:<strong> </strong><em>Lemna perpusilla</em>, physiological condition, phytoremediation, production performance.</p><p><strong> </strong></p><p> </p><p align="center"><strong>ABSTRAK</strong></p><p>Penelitian ini bertujuan mengevaluasi kinerja produksi dan fisiologi ikan nila dengan penggunaan <em>Lemna perpusilla </em>sebagai fitoremediator pada sistem resirkulasi. Rancangan penelitian yang digunakan adalah acak lengkap dengan dua perlakuan dan tiga ulangan. Ikan nila dipelihara pada kolam tanpa <em>L. perpusilla</em> (TL) dan ikan nila dipelihara pada kolam dengan <em>L. perpusilla </em>(L). Ikan yang digunakan dalam penelitian ini adalah benih ikan nila dengan panjang baku 9,98 ± 0,08 cm dan bobot rata-rata 36,27 ± 1,07 g. Padat tebar ikan tiap kolam pemeliharaan 46 ekor/kolamdengan ukuran kolam 275×100×60 cm³. Setiap kolam diberi sekat dengan luasan 44,1% <em>L. perpusilla</em> dari luasan kolam. Ikan nila dipelihara selama 60 hari pemeliharaan dengan pakan berupa pakan komersial dan <em>L. perpusilla</em> dengan jumlah pakan masing-masing 2% dan 1% dari biomassa. Pada pagi dan sore hari diberi pakan komersial, dan siang hari ikan diberi pakan <em>L. perpusilla</em>. Hasil penelitian ini menunjukkan bahwa ikan nila yang dipelihara dengan fitoremediasi <em>L. perpusilla </em>menghasilkan kinerja produksi dan kondisi fisiologis yang normal. Keunggulan sistem ini adalah menghasilkan nilai konversi pakan<em> </em>yang lebih rendah, nilai efisiensi pemberian pakan, dan koefisien keseragaman bobot yang lebih tinggi.</p><p> </p><p>Kata kunci :<em> </em>fitoremediasi, <em>Lemna perpusilla</em>, kondisi fisiologis, kinerja produksi.</p><p> </p>