scholarly journals Determination of stocking density limits for Crassostrea gigas larvae reared in flow-through and recirculating aquaculture systems and interaction between larval density and biofilm formation

2017 ◽  
Vol 30 ◽  
pp. 29 ◽  
Author(s):  
Katia Asmani ◽  
Bruno Petton ◽  
Jacqueline Le Grand ◽  
Jérôme Mounier ◽  
René Robert ◽  
...  
Keyword(s):  
Crassostrea Gigas ◽  
Biofilm Formation ◽  
Larval Density ◽  
Stocking Density ◽  
Rrna Gene ◽  
Larval Rearing ◽  
Filamentous Bacteria ◽  
Recirculating Aquaculture ◽  
Recirculating Aquaculture Systems ◽  
Flow Through

The first aim of this study was to determine the stocking density limits for Pacific oyster Crassostrea gigas larvae reared in flow-through system (FTS) and recirculating aquaculture systems (RAS). The second aim was to examine biofilm formation on the larval tank wall and its interaction with larvae growth. Three larvae concentrations were tested: 50, 150, and 300 mL−1. Chemical parameters and larvae performance were measured. The biofilm was observed by scanning electron microscopy, and its bacterial composition was investigated by pyrosequencing analysis of part of the 16S rRNA gene. The highest growth (13 µm day–1), survival (87%) and metamorphosis (50%) rates were observed in FTS at 50 larvae mL–1, while lower and similar performances occurred at 150 larvae mL–1 in both systems. At 300 larvae mL−1, performances dropped with occurrence of mortality. Biofilm thickness increased with larval density. The pioneer bacteria were coccobacilli followed by filamentous bacteria. The latter constituted abundant braids at the end of rearing at high larval concentrations. The first colonizers were mainly Rhodobacteraceae (α-Proteobacteria). The filamentous bacteria were Saprospirae (Bacteroidetes) and Anaerolineae (Chloroflexi). The biofilm was also made up of other minor groups, including Actinobacteria, Planctomycetes, δ-, γ-Proteobacteria, and Flavobacteriales. The biofilm's composition was more similar to that found in a sewage reactor than in open-sea collectors, which might negatively influence larval rearing due to potential metabolites. This first study on biofilms provides insights into the interaction between rearing density and larvae performance.

scholarly journals SUBSTANTIATING SCALES OF SIMILARITY OF OPTICAL QUANTITIES IN HYDROBIONT GROWING SYSTEMS

2021 ◽  
Vol 2021 (1) ◽  
pp. 7-13
Author(s):  
Alexander Alekseevich Nedostup ◽  
Alexey Olegovich Razhev ◽  
Evgeniy Ivanovich Khrustalyov ◽  
Kseniia Andreevna Molchanova
Keyword(s):  
Computer Vision ◽  
Optimal Algorithm ◽  
Stocking Density ◽  
Aquatic Organisms ◽  
Similarity Criteria ◽  
Light Effect ◽  
Behavioral Reactions ◽  
Recirculating Aquaculture ◽  
Recirculating Aquaculture Systems ◽  
Growing Conditions

The article highlights the problems of physical modeling the elements of recirculating aquaculture systems (RAS) and open aquaculture cages (OAC) for hydrobionts growing, in particular, the question of substantiating the rules of optical quantities similarity has been raised. Formulation of the problem is based on the assumption that using the computer vision which controls the behavioral reactions of hydrobionts to the growing conditions (e.g. light effect) will make the biotechnological process controllable in RAS and OAC and, as a result, more efficient. Evaluating the light effect on biological objects as to the depth of its penetration into the basins, the degree of its dispersion among the aquatic organisms and other characteristics can become an important element of computer vision. This fact will help to choose the optimal algorithm for the biotechnical process, for example, to calculate the daily feed portion and feeding periods, to define the optimal place for feeding, to determine the appropriate sorting time, the optimal stocking density, etc. There have been proposed the additional similarity scales for optical quantities, methods for their calculation and graphs of their dependences on the geometric scale Cl. However, one should know that achieving the complete similarity is absolutely impossible, no matter how large the list of similarity criteria is.

scholarly journals Effect of Copper Ion Sterilization on Bacterial Community in a Freshwater Recirculating Aquaculture System

2022 ◽  
Vol 79 (2) ◽  
Author(s):  
Jianjun Shan ◽  
Xiaoqing Tian ◽  
Chongwu Guan ◽  
Chenglin Zhang ◽  
Yulei Zhang ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Bacterial Species ◽  
Copper Ion ◽  
Ammonia Nitrogen ◽  
Ion Concentration ◽  
Rrna Gene ◽  
Brachydanio Rerio ◽  
Illumina Hiseq ◽  
Recirculating Aquaculture ◽  
Recirculating Aquaculture Systems

AbstractThe study aimed to evaluate the safety of copper ion sterilization based on copper ion residues in zebrafish (Brachydanio rerio), as well as bacterial community structure and diversity in recirculating aquaculture systems (RASs). The copper ion content was determined using national food safety standard GB 5009.13-2017. Bacterial community structures and alpha and beta diversity indexes were examined using the 16S rRNA gene sequences produced by Illumina HiSeq sequencing. The results revealed no significant copper ion enrichment in B. rerio when the copper ion concentration was 0.15 mg/L. The relative abundances of Erythrobacter, nitrite bacteria, and Flavanobacteria were clearly higher in the treatment group than in the control and differences in bacterial species richness and diversity were obvious. In addition, there was no sharp decrease in the microflora at the outflow of the copper ion generator. In conjunction with the changes in ammonia nitrogen, nitrate, and nitrite concentrations during the experiment, the results indicated that there were no significant effects on the purification efficacy of the biological filter, but the abundances of beneficial bacteria increased significantly. This is of great relevance in order to understand the response of bacterial communities affected by changing environmental conditions, such as copper ion sterilization.

scholarly journals Retrofitting Sea Cucumber Nursery Tanks to Recirculating Aquaculture Systems for Highly Intensive Litopenaeus vannamei Aquaculture

2021 ◽  
Vol 11 (20) ◽  
pp. 9478
Author(s):  
Yishuai Du ◽  
Jianping Xu ◽  
Li Zhou ◽  
Fudi Chen ◽  
Tianlong Qiu ◽  
...  
Keyword(s):  
Litopenaeus Vannamei ◽  
Sea Cucumber ◽  
Stocking Density ◽  
Ammonia Nitrogen ◽  
Average Weight ◽  
Recirculating Aquaculture ◽  
Nitrite Nitrogen ◽  
Innovative Methodology ◽  
Recirculating Aquaculture Systems ◽  
Total Ammonia

Designing good recirculating aquaculture systems (RASs) is challenging in shrimp aquaculture. In this study, two sets of RASs were constructed using sea cucumber nursery tanks for rearing Litopenaeus vannamei. Recirculating aquaculture was supported by key technologies such as sewage collection and aeration systems adapted to the rectangular tanks and technologies for the removal of sewage, shrimp shells, and dead individuals. Six-hundred and eighty-five thousand juveniles were selected for rearing in the newly constructed RASs, where the average stocking density was 1013 shrimp/m3. During the recirculating aquaculture period of 53 days, the water temperature of the tanks was 24–31 °C, the salinity was 25–32‰, the pH was 6.4–8.2, the DO was ≥ 4.9 mg/L, the concentration of total ammonia nitrogen (TAN) was maintained between 0.17 and 4.9 mg/L, the concentration of nitrite nitrogen (NO2-N) was between 0.12 and 4.7 mg/L, and the total number of Vibrio bacteria remained between 330 and 9700 cfu/mL. At the end of the experiment, the final average weight of individual shrimp was 13.43 g, and the average yield reached 12.92 kg/m3. The great improvement in growth performance marks a breakthrough in RAS technology of shrimp, and it supports the use of an innovative methodology for the retrofitting and utilization of idle sea cucumber nursery tanks.

scholarly journals Effects of Stocking Density on Growth Performance and Stress Responses of Bester and Bester ♀ × Beluga ♂ Juveniles in Recirculating Aquaculture Systems

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2292
Author(s):  
Lorena Dediu ◽  
Angelica Docan ◽  
Mirela Crețu ◽  
Iulia Grecu ◽  
Alina Mogodan ◽  
...  
Keyword(s):  
Growth Performance ◽  
Stress Responses ◽  
Stocking Density ◽  
Serum Cortisol ◽  
Lower Serum ◽  
Serum Parameters ◽  
Hematological Indices ◽  
Recirculating Aquaculture ◽  
Crowding Stress ◽  
Recirculating Aquaculture Systems

The study aimed to compare the growth performance and physiological responses of bester (B) and backcrossed bester ♀ × beluga ♂ (BB) in response to crowding stress under different stocking densities, as well as to establish a threshold stocking density for rearing BB in a recirculating aquaculture system (RAS) without welfare impairment. For this purpose, in the first trial (T1), B (181.15 ± 21.21 g) and BB fingerlings (181.98 ± 28.65 g) were reared in two stocking densities of 2 kg/m2 and 4 kg/m2 in fiberglass tanks (1 m3) for 6 weeks. In a parallel trial (T2), the BB hybrids (335.24 ± 39.30 g) were kept in four initial stocking densities, ranging from 5 kg/m2 to 12 kg/m2. The results of T1 revealed better growth indices (i.e., final mean weight, weight gain, specific growth rate) at lower stocking densities for both hybrids; however, in terms of growth performance, the BB hybrid showed better results when compared with the B hybrid. BB hybrids registered significantly (p < 0.05) lower serum cortisol and MDA and higher lysozyme than B hybrids, showing higher tolerance to crowding stress. Nevertheless, at higher densities, selected serum parameters (i.e., hematological indices, cortisol, glucose, protein, malondialdehyde, lysozyme) and growth performance indices used to evaluate the hybrids indicate that high stocking density could affect the growth and welfare of BB hybrids, and that the selected serum parameters could be used as good indicators for chronic stress caused by overcrowding conditions.

scholarly journals Stocking density effect on survival and growth of early life stages of maraena whitefish, Coregonus maraena (Actinopterygii: Salmoniformes: Salmonidae)

2021 ◽  
Vol 51 (2) ◽  
pp. 139-144
Author(s):  
Vlastimil Stejskal ◽  
Jan Matousek ◽  
Roman Sebesta ◽  
Joanna Nowosad ◽  
Mateusz Sikora ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Stocking Density ◽  
Negative Consequences ◽  
Final Body Weight ◽  
Growth And Survival ◽  
Total Length ◽  
Recirculating Aquaculture ◽  
Recirculating Aquaculture Systems ◽  
Survival And Growth ◽  
Size Heterogeneity

The maraena whitefish, Coregonus maraena (Bloch, 1779), is often considered a suitable candidate for intensive aquaculture diversification in the EU. However, only a few such farms in Europe are in operation. Rearing this species in recirculating aquaculture systems is a recent innovation, and optimisation is necessary to standardise aspects of larviculture. This 30-day study investigated the effect of stocking densities of 25/L, 50/L, 100/L, and 200/L on the survival and growth of maraena whitefish larvae in a recirculating aquaculture system. The four groups of larvae (initial weight = 7.4 ± 0.1 mg; initial total length = 13.0 ± 0.1 mm) in three repetitions were reared in a recirculating system. Larvae were fed fresh live brine shrimp metanauplii every 3 h at a rate converted to larval stocking density. After the experiment, 10 larvae from each tank (30 of each density group) were weighed on a digital microbalance (ABJ 220-4M KERN, Germany, readout = 0.1 mg) and measured manually on images taken with Leica MZ16 A stereomicroscope and a digital colour camera with 5-megapixel resolution for Leica DFC420 Image Analysis. No significant differences in final body weight, total length, size heterogeneity, condition factor, or survival were found among treatments (P &gt; 0.05). The highest non-significant survival rate and growth parameters were observed in larvae reared at 25/L. On the contrary, it is possible to rear maraena whitefish larvae at high stocking density without any subsequent negative consequences for growth and survival. As no significant differences in any evaluated parameter were observed between groups of larvae at the highest and lowest stocking density, we conclude that it is possible to rear maraena whitefish larvae at high stocking density (and 200/L) without any subsequent negative consequences for growth and survival.

scholarly journals 16S rRNA Gene Amplicon Sequencing of Microbiota in Polybutylene Succinate Adipate-Packed Denitrification Reactors Used for Water Treatment of Land-Based Recirculating Aquaculture Systems

2019 ◽  
Vol 8 (47) ◽  
Author(s):  
Takeshi Yamada ◽  
Masako Hamada ◽  
Miku Nakagawa ◽  
Nobukazu Sato ◽  
Akinori Ando ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Amplicon Sequencing ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
High Quality ◽  
Recirculating Aquaculture ◽  
Recirculating Aquaculture Systems ◽  
Polybutylene Succinate ◽  
The 16S Rrna Gene

Information on the microbiota in polybutylene succinate adipate (PBSA)-packed denitrification reactors is limited. Here, we provide 439,817 high-quality reads of the 16S rRNA gene sequences of microbiota in PBSA-packed denitrification reactors used for land-based recirculating aquaculture. The predominant microorganisms belonged to the following families: Nocardiaceae, Chitinophagaceae, Xanthobacteraceae, Burkholderiaceae, Rhodocyclaceae, Pseudomonadaceae, Rhodanobacteraceae, and Xanthomonadaceae.

scholarly journals Understanding structure/function relationships in nitrifying microbial communities after cross-transfer between freshwater and seawater

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Blanca M. Gonzalez-Silva ◽  
Kjell Rune Jonassen ◽  
Ingrid Bakke ◽  
Kjetill Østgaard ◽  
Olav Vadstein
Keyword(s):  
Microbial Communities ◽  
Rrna Gene ◽  
Physiological Plasticity ◽  
Oxidation Rates ◽  
Salinity Changes ◽  
Recirculating Aquaculture ◽  
Seawater Salinity ◽  
Recirculating Aquaculture Systems ◽  
Before And After

AbstractIn this study, nitrification before and after abrupt cross-transfer in salinity was investigated in two moving bed biofilm reactors inoculated with nitrifying cultures that had adaptation to freshwater (FR) and seawater salinities (SR). FR and SR MBRRs were exposed to short and long term cross-transfer in salinity, and the functional capacity of nitrifying microbial communities was quantified by the estimation of ammonia and nitrite oxidation rates. Salinity induced successions were evaluated before and after salinity change by deep sequencing of 16S rRNA gene amplicons and statistical analysis. The bacterial community structure was characterized and Venn diagrams were included. The results indicated that after salinity cross-transfer, the FR was not significantly recovered at seawater salinity whereas SR showed high resistance to stress caused by low-salt. Succession and physiological plasticity were the main mechanisms of the long-term adaption of the nitrifying communities exposed to abrupt salinity changes. Independently of salinity, some nitrifiers presented high physiological plasticity towards salinity and were very successful at both zero and full seawater salinity. SR culture is robust and suitable inoculum for ammonium removal from recirculating aquaculture systems and industrial wastewaters with variable and fast salinity changes. Our findings contradict the current perspective of the significance of salinity on the structure of nitrifying communities.

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