Species Of Aquatic Animals Research Articles

Environmental Compatibility and Genome Flexibility of Klebsiella oxytoca Isolated from Eight Species of Aquatic Animals

Klebsiella oxytoca is an emerging pathogen that can cause life-threatening infectious diseases in humans. Recently, we firstly reported for the first time the presence of K. oxytoca in edible aquatic animals. In this study, we further investigated its bacterial environmental fitness and genome evolution signatures. The results revealed that K. oxytoca isolates (n = 8), originating from eight species of aquatic animals, were capable of growing under a broad spectrum of environmental conditions (pH 4.5–8.5, 0.5–6.5% NaCl), with different biofilm formation and swimming mobility profiles. The genome sequences of the K. oxytoca isolates were determined (5.84–6.02 Mb, 55.07–56.06% GC content). Strikingly, numerous putative mobile genetic elements (MGEs), particularly genomic islands (GIs, n = 105) and prophages (n = 24), were found in the K. oxytoca genomes, which provided the bacterium with specific adaptation traits, such as resistance, virulence, and material metabolism. Interestingly, the identified prophage-related clusters were derived from Burkholderia spp., Enterobacter spp., Klebsiella spp., Pseudomonas spp., and Haemophilus spp., suggesting phage transmission across Klebsiella and the other four genera. Many strain-specific (n = 10–447) genes were present in the K. oxytoca genomes, whereas the CRISPR-Cas protein-encoding gene was absent, indicating likely active horizontal gene transfer (HGT) and considerable genome variation in K. oxytoca evolution. Overall, the results of this study are the first to demonstrate the environmental compatibility and genome flexibility of K. oxytoca of aquatic animal origins.

Coculture of aquatic animals and paddy in brackish water: Evaluation of the growth of daily growth and morphometrics of tilapia (Oreochromis niloticus) as a fed species

A study on the cultivation of tilapia (Oreochromis niloticus) in brackish water using co-culture systems (polyculture, IMTA-non paddy, and IMTA-paddy) and monoculture systems was evaluated on a laboratory scale to determine its growth. Several species of aquatic animals and paddy (floating system) were combined with tilapia reared in plastic tanks for 28 days. Tilapia were fed four times a day at a feeding rate of 10% of biomass. The highest specific growth rate (SGR), IMTA-paddy system (4.24±0.08% day-1), polyculture (4.13±0.06% day-1), IMTA-non paddy (3.84±0.23% day-1), and monoculture (3.80±0.05% day-1). The same pattern was found in the addition of morphometric characteristics (AMC). Total length, standard length, body length, and height respectively from the highest IMTA-paddy system (2.49±0.12; 2.14±0.12; 1.81±0.14; 0.49±0.19 g), polyculture (2.32±0.16; 2.07±0.09; 1.72±0.11; 0.41±0.11 g), IMTA-non paddy (2.18±0.12; 1.78±0.15; 1.62±0.15; 0.33±0.14 g), and monoculture (2.02±0,09 1.67±0.08; 1.57±0.08; 0.30±0.10 g). Analysis of variance indicated that SGR and AMC of tilapia were significantly influenced by the culture system (P<0.05). The SGR and AMC in the IMTA-paddy system were significantly higher (P<0.05) than those in the monoculture and IMTA-non-paddy systems, but not significantly different (P>0.05) from those in the polyculture system. In general, tilapia growth was higher in co-culture systems than in monoculture systems in brackish water, which led to the diversification of aquaculture production.Keywords: Brackish water; Co-culture; Growth; Nile tilapia; Rice.

Survival and Genome Evolution Signatures of Klebsiella pneumoniae Isolates Originated in Seven Species of Aquatic Animals

Klebsiella pneumoniae can cause life-threatening pneumonia in humans. The bacterium is also the causative agent of nosocomial infection diseases. In our recent research, we reported, for the first time, the presence of K. pneumoniae in fourteen species of aquatic animals sampled in Shanghai, China. Here, we further investigated the bacterial survival and genome evolution traits. The results revealed that K. pneumoniae isolates (n = 7), recovered from 7 species of commonly consumed aquatic animals, had multiple antibiotic and heavy metal resistance profiles. The isolates were capable of growing vigorously at pH 4.5−7.5 and 0.5−1.0% NaCl in TSB medium at 37 °C. Draft genome sequences of the K. pneumoniae isolates were determined (5,256,522−5,857,823 bp, 56.35–57.81% GC contents), which carried many mobile genetic elements, including genomic islands (n = 87), prophages (n = 14), integrons (n = 4), and insertion sequences (n = 22), indicating possible active horizontal gene transfer during the genome evolution. Meanwhile, numerous strain-specific (n = 199−605) genes, antibiotic resistance (n = 20−35, e.g., β-lactamase) genes, and virulence (n = 43−59, e.g., enterobactin)-related genes, were also identified, demonstrating considerable genome variation in the K. pneumoniae isolates. Overall, the results of this study fill prior gaps in understanding the K. pneumoniae genomes derived from aquatic animals.

First Report of Potentially Pathogenic Klebsiella pneumoniae from Serotype K2 in Mollusk Tegillarca granosa and Genetic Diversity of Klebsiella pneumoniae in 14 Species of Edible Aquatic Animals.

Klebsiella pneumoniae can cause serious pneumonitis in humans. The bacterium is also the common causative agent of hospital-acquired multidrug-resistant (MDR) infections. Here we for the first time reported the genetic diversity of K. pneumoniae strains in 14 species of edible aquatic animals sampled in the summer of 2018 and 2019 in Shanghai, China. Virulence-related genes were present in the K. pneumoniae strains (n = 94), including the entB (98.9%), mrkD (85.1%), fimH (50.0%), and ybtA (14.9%) strains. Resistance to sulfamethoxazole-trimethoprim was the most prevalent (52.1%), followed by chloramphenicol (31.9%), and tetracycline (27.7%), among the strains, wherein 34.0% had MDR phenotypes. Meanwhile, most strains were tolerant to heavy metals Cu2+ (96.8%), Cr3+ (96.8%), Zn2+ (91.5%), Pb2+ (89.4%), and Hg2+ (81.9%). Remarkably, a higher abundance of the bacterium was found in bottom-dwelling aquatic animals, among which mollusk Tegillarca granosa contained K. pneumoniae 8-2-5-4 isolate from serotype K2 (ST-2026). Genome features of the potentially pathogenic isolate were characterized. The enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR)-based genome fingerprinting classified the 94 K. pneumoniae strains into 76 ERIC genotypes with 63 singletons, demonstrating considerable genetic diversity in the strains. The findings of this study fill the gap in the risk assessment of K. pneumoniae in edible aquatic animals.

A miniaturized electrothermal array for rapid analysis of temperature preference behaviors in ecology and ecotoxicology

Due to technical limitations, there have been minimal studies performed on thermal preferences and thermotactic behaviors of aquatic ectotherm species commonly used in ecotoxicity testing. In this work, we demonstrate an innovative, purpose-built and miniaturized electrothermal array for rapid thermal preference behavioral tests. We applied the novel platform to define thermal preferences in multiple invertebrate and vertebrate species. Specifically, Dugesia notogaea (freshwater planarians), Chironomus tepperi (nonbiting midge larvae), Ostracoda (seed shrimp), Artemia franciscana (brine shrimp), Daphnia carinata (water flea), Austrochiltonia subtenuis (freshwater amphipod), Physa acuta (freshwater snail), Potamopyrgus antipodarum (New Zealand mud snail) and larval stage of Danio rerio (zebrafish) were tested. The Australian freshwater water fleas, amphipods, snail Physa acuta as well as zebrafish exhibited the most consistent preference to cool zones and clear avoidance of zones >27 °C out of nine species tested. Our results indicate the larval stage of zebrafish as the most responsive species highly suitable for prospective development of multidimensional behavioral test batteries. We also showcase preliminary data that environmentally relevant concentrations of pharmaceutical pollutants such as non-steroidal anti-inflammatory drug (NSAID) ibuprofen (9800 ng/L) and insecticide imidacloprid (4600 ng/L) but not anti-depressant venlafaxine (2200 ng/L) and (iv) anticonvulsant medications gabapentin (400 ng/L) can perturb thermal preference behavior of larval zebrafish. Collectively our results demonstrate the utility of simple and inexpensive thermoelectric technology in rapid exploration of thermal preference in diverse species of aquatic animals. We postulate that more broadly such technologies can also have added value in ecotoxicity testing of emerging contaminants.

Impact of Mekong River biodiversity on the food culture of women and children in Prey Veng, Cambodia

AbstractSituated in the heart of the Mekong River basin, the biodiversity of Cambodian freshwaters is high, with around 475 fish species. Fisheries have shaped Cambodian culture, including traditional diets. Fish and other aquatic animals are the main and culturally preferred animal-source foods in a population vulnerable to food insecurity and malnutrition. The food culture of consuming fish with the bones and head is nutritionally valuable, providing high-quality nutrients. The objective of this study was to assess the consumption of fish and other aquatic animals among mothers and their young children, with details on species, types of processing, and parts consumed. We interviewed 100 mothers in Prey Veng Province, Cambodia, on fish and other aquatic animals consumed by themselves and their children (one child per mother) during the preceding rainy season. To support recall of fish consumption, we used 157 cards with pictures of fish and other aquatic animal species and 11 cards with processed fish. Our results showed that species diversity in mothers’ diets was higher than that of their children; on average, mothers and children consumed 69 and 14 species of fish, eight and one species of other aquatic animals, respectively, in the preceding rainy season. On average, mothers reported they knew of 113 fish species and 14 other species available in their surrounding environments. Consuming fish with the head and bones is common among mothers but not children. Our study showed that the rich biodiversity of aquatic animals in the Mekong River is reflected in the food culture of mothers, but not in children. Consequently, children in their most critical period, do not harness the nutritional benefits from the rich aquatic biodiversity. We suggest policymakers recommend feeding young children with a larger diversity of aquatic animals and promoting fish processing to allow young children to benefit from the rich aquatic diversity and their nutrient-rich parts.

Macrofossil studies of Lateglacial sediments from Regstrup, north-west Sjælland, Denmark

Studies of macrofossils indicate that the vegetation near Regstrup in north-west Sjælland, Denmark, from c. 13 600 to 13 500 cal. years BP was dominated by dwarf-shrub heaths. Betula pubescens (downy birch) arrived at c. 13 500 cal. years BP and became common after c. 13 200 cal. years BP. Open forests with B. pubescens and Populus tremula (aspen) dominated until c. 12 500 cal. years BP, indicating that an Allerød-type environment persisted for c. 350 years after the cooling at the onset of the Younger Dryas, which is dated to c. 12 850 years BP in ice cores from Green-land. Betula nana was common after c. 12 500 cal. years BP, indicating a return to a tundra-like landscape with dwarf-shrub heaths. The fauna included Rangifer taran-dus (reindeer), Castor fiber (Eurasian beaver) and possibly Lemmus lemmus (Norway lemming). The lake deposits contain remains of many species of aquatic plants and animals, including three species of fish. The flora and fauna indicate that the lake water was fairly nutrient-rich and alkaline.

Influence of regular addition of ore on treatment efficiency and aquatic organisms in living machine system for black water treatment

Living machine (LM) system is widely exploited as an ecological restoration technology in decentralized wastewater treatment. This is the first study reporting the influence of regular addition of mixed ore powder (maifanite, zeolite, oyster shell, and montmorillonite) on an open aerobic reactor of LM system for black water treatment. The maximum removal efficiency of chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) achieved 50.74%, 25.18%, and 17.19%, respectively, after the mixed ore addition. Furthermore, the numbers and species of algae, zooplankton, and other aquatic animals considerably changed with the mixed ore addition. Compared with those in control system, the maximum increase of the relative abundances of Acinetobacter, Chryseobacterium, C39, Pseudomonas, Flavobacterium, Novosphingobium, Rhodoluna, Mycobacterium, and Malikia in the experimental system reached 28.82%, 18.00%, 12.39%, 15.12%, 13.67%, 6.65%, 11.78%, 7.83%, and 10.50%, respectively. Presence of Rhodoluna suggests that addition of the mixed ore powder may be benignant and beneficial for formation of a healthy ecological environment during black water treatment with LM system.

Lagrangian analysis of bio-inspired vortex ring formation

Pulsatile jet propulsion is a highly energy-efficient swimming mode used by various species of aquatic animals that continues to inspire engineers of underwater vehicles. Here, we present a bio-inspired jet propulsor that combines the flexible hull of a jellyfish with the compression motion of a scallop to create individual vortex rings for thrust generation. Similar to the biological jetters, our propulsor generates a nonlinear time-varying exit velocity profile and has a finite volume capacity. The formation process of the vortices generated by this jet profile is analysed using time-resolved velocity field measurements. The transient development of the vortex properties is characterised based on the evolution of ridges in the finite-time Lyapunov exponent field and on local extrema in the pressure field derived from the velocity data. Special attention is directed toward the vortex merging observed in the trailing shear layer. During vortex merging, the Lagrangian vortex boundaries first contract in the streamwise direction before expanding in the normal direction to keep the non-dimensional energy at its minimum value, in agreement with the Kelvin–Benjamin variational principle. The circulation, diameter and translational velocity of the vortex increase due to merging. The vortex merging takes place because the velocity of the trailing vortex is higher than the velocity of the main vortex ring prior to merging. The comparison of the temporal evolution of the Lagrangian vortex boundaries and the pressure-based vortex delimiters confirms that features in the pressure field serve as accurate and robust observables for the vortex formation process.

Comparative proteomics and secretomics revealed virulence, and coresistance-related factors in non O1/O139 Vibrio cholerae recovered from 16 species of consumable aquatic animals

Vibrio cholerae can cause pandemic cholera in humans. The bacterium resides in aquatic environments worldwide. Identification of risk factors of V. cholerae in aquatic products is imperative for assuming food safety. In this study, we determined virulence-associated genes, cross-resistance between antibiotics and heavy metals, and genome fingerprinting profiles of non O1/O139 V. cholerae isolates (n = 20) recovered from 16 species of consumable aquatic animals. Secretomes and proteomes of V. cholerae with distinct genotypes and phenotypes were obtained by using two-dimensional gel electrophoresis (2D-GE) and/or liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques. Comparative secretomic analysis revealed 4 common and 45 differential extracellular proteins among 20 V. cholerae strains, including 13 virulence- and 8 resistance-associated proteins. A total of 21,972 intracellular proteins were identified, and comparative proteomic analysis revealed 215 common and 913 differential intracellular proteins, including 22 virulence- and 8 resistance-associated proteins. Additionally, different secretomes and proteomes were observed between V. cholerae isolates of fish and shellfish origins. A number of novel proteins with unknown function and strain-specific proteins were also discovered in the V. cholerae isolates. SignificanceV. cholerae can cause pandemic cholera in humans. The bacterium is distributed in aquatic environments worldwide. Identification of risk factors of V. cholerae in aquatic products is imperative for assuming food safety. Non-O1/O139 V. cholerae has been reported to cause sporadic cholera-like diarrhea and bacteremia diseases, which indicates virulence factors rather than the major cholera toxin (CT) exist. This study for the first time investigated proteomes and secretomes of non-O1/O139 V. cholerae originating from aquatic animals. This resulted in the identification of a number of virulence and coresistance-related factors, as well as novel proteins and strain-specific proteins in V. cholerae isolates recovered from 16 species of consumable aquatic animals. These results fill gaps for better understanding of pathogenesis and resistance of V. cholerae, and also support the increasing need for novel diagnosis and vaccine targets against the leading waterborne pathogen worldwide.

First Experimental Evidence for the Presence of Potentially Virulent Klebsiella oxytoca in 14 Species of Commonly Consumed Aquatic Animals, and Phenotyping and Genotyping of K. oxytoca Isolates.

Klebsiella oxytoca is a recently emerging pathogen that can cause necrotizing enterocolitis, hemorrhagic colitis, sepsis-associated purpura fulminans, and infective endocarditis in humans. The bacterium is ubiquitous in water and soil environments. Nevertheless, current literature on K. oxytoca in aquatic products is rare. In this study, we surveyed K. oxytoca contamination in 41 species of consumable aquatic animals sold in July, August, and September of 2018 and 2019 in Shanghai, China, 40 of which had no history of carrying this bacterium. K. oxytoca was for the first time isolated from 14 species with high abundance in benthic animals. None of the K. oxytoca isolates (n = 125) harbored toxin genes mviM, tisB, and yqgB. However, a high occurrence of virulence-associated genes was observed, including brkB (73.6%), cdcB (66.4%), pduV (64.8%), and virk (63.2%). Resistance to sulphamethoxazole-trimethoprim (56.0%) was the most predominant among the isolates, followed by chloramphenicol (6.4%), tetracycline (5.6%), and kanamycin (3.2%). Approximately 8.0% of the isolates displayed multidrug resistant phenotypes. Meanwhile, high percentages of the isolates tolerated the heavy metals Cu2+ (84.8%), Pb2+ (80.8%), Cr3+ (66.4%), Zn2+ (66.4%), and Hg2+ (49.6%). Different virulence and resistance profiles were observed among K. oxytoca isolates in 3 types and 14 species of aquatic animals. The ERIC-PCR-based genome fingerprinting of the 125 K. oxytoca isolates revealed 108 ERIC genotypes with 79 singletons, which demonstrated the genetic diversity of the isolates. The results of this study fill gaps for policy and research in the risk assessment of K. oxytoca in consumable aquatic animals.

Patterns of phytoplankton community structure and diversity in aquaculture ponds, Henan, China

In aquaculture, phytoplankton contribute to primary productivity, helping maintain fishery harvests and water stabilization. To better understand the drivers controlling phytoplankton communities, sampling was conducted during two seasons in 185 aquaculture ponds that cultured five species of aquatic animals (channel catfish, common carp, grass carp, crayfish and largemouth bass). Principal coordinate analysis (PCoA), redundancy analysis (RDA), and generalized linear model (GLM) were applied to quantify the relative importance of multiple factors to phytoplankton species composition and diversity. The PCoA results demonstrated that in spring, phytoplankton species composition showed no distinct differences among the 5 cultivated-animal ponds. In summer, phytoplankton species composition had a distinct pattern, which was clustered into three distinct groups. The RDA results revealed that the variation in the phytoplankton composition was closely correlated with the water temperature, conductivity, dissolved organic carbon (DOC), alkalinity, and nitrate in spring. In summer, different variables, including cultivated animals, alkalinity, pH and dissolved oxygen (DO), were responsible for explaining species composition patterns. In spring, no significant difference in phytoplankton α-diversity was found among the 5 cultivated-animal ponds. In summer, significantly higher α-diversity was found in the channel catfish and crayfish ponds than in the other ponds. GLM analysis showed that phytoplankton density, cultivated animals, and conductivity can be used to explain phytoplankton diversity. Although no effect of cultivated animals was found during the early aquaculture stage, the results from the summer samples demonstrated that cultivated animals have an important influence on phytoplankton communities. Therefore, we suggest that in intensive fish-stocking ecosystems, top-down effect is an important strength on phytoplankton communities. In terms of preventing algal blooms, a low density of phytoplankton is important for maintaining high phytoplankton diversity and water stabilization in aquaculture. Our results can provide useful information for water management practices in aquaculture ponds.

Residual levels of antimicrobial agents and heavy metals in 41 species of commonly consumed aquatic products in Shanghai, China, and cumulative exposure risk to children and teenagers

Currently, few integrated studies of residual antimicrobial agents and heavy metals in aquatic products and their cumulative exposure risk to children and teenagers exist. In this study, residual levels of 37 antimicrobial drugs and 5 heavy metals in 41 species of commonly consumed aquatic food animals were determined using ultra-high-performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS) and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. All samples (n = 108) were collected in large aquatic markets in the summers of 2018 and 2019 in Shanghai, China. The results revealed that total 10 antibiotics were detected positive in the samples with an overall detection frequency of 61.3%. Chloramphenicol residue (47.2%) was dominant in the samples, followed by ampicillin (31.1%), and ciprofloxacin (15.1%), while lower occurrences of the other 7 drugs were found (0.9–3.8%). The residual chloramphenicol, ampicillin, and sulfapyridine (1.9%) exceeded their maximum residue limits (MRLs) with failed sample rates (FSRs) of 47.2%, 3.8%, and 1.9%, respectively. Meanwhile, four heavy metals, namely, copper (Cu), mercury (Hg), lead (Pb), and cadmium (Cd) were observed in the samples with positive sample rates (PSRs) of 100%, 100%, 77.4%, and 34.0%, respectively, none of which exceeded their MRLs. Moreover, our data indicated that residual levels of heavy metals (Cu, Hg, and Pb) were closely related with local gross domestic products (GDPs). Additionally, distinct antibiotic and heavy metal residue profiles were discovered among different origins, types and species of the consumable aquatic animals. Monte Carlo simulation analysis revealed that cumulative exposure to the heavy metals and antibiotics posed a low risk to children and teenagers aged 3–17 years in Shanghai. Consequently, the results here provide useful data in support of the increasing need of risk assessment of aquatic products and a reference for the development of aquatic product quality standards.

First Experimental Evidence for the Presence of Potentially Toxic Vibrio cholerae in Snails, and Virulence, Cross-Resistance and Genetic Diversity of the Bacterium in 36 Species of Aquatic Food Animals.

Vibrio cholerae is the most common waterborne pathogen that can cause pandemic cholera in humans. Continuous monitoring of V. cholerae contamination in aquatic products is crucial for assuring food safety. In this study, we determined the virulence, cross-resistance between antibiotics and heavy metals, and genetic diversity of V. cholerae isolates from 36 species of aquatic food animals, nearly two-thirds of which have not been previously detected. None of the V. cholerae isolates (n = 203) harbored the cholera toxin genes ctxAB (0.0%). However, isolates carrying virulence genes tcpA (0.98%), ace (0.5%), and zot (0.5%) were discovered, which originated from the snail Cipangopaludina chinensis. High occurrences were observed for virulence-associated genes, including hapA (73.4%), rtxCABD (68.0–41.9%), tlh (54.2%), and hlyA (37.9%). Resistance to moxfloxacin (74.9%) was most predominant resistance among the isolates, followed by ampicillin (59.1%) and rifampicin (32.5%). Approximately 58.6% of the isolates displayed multidrug resistant phenotypes. Meanwhile, high percentages of the isolates tolerated the heavy metals Hg2+ (67.0%), Pb2+ (57.6%), and Zn2+ (57.6%). Distinct virulence and cross-resistance profiles were discovered among the V. cholerae isolates in 13 species of aquatic food animals. The ERIC-PCR-based genome fingerprinting of the 203 V. cholerae isolates revealed 170 ERIC-genotypes, which demonstrated considerable genomic variation among the isolates. Overall, the results of this study provide useful data to fill gaps for policy and research related to the risk assessment of V. cholerae contamination in aquatic products.

Quantitative Analysis of Polystyrene and Poly(methyl methacrylate) Nanoplastics in Tissues of Aquatic Animals.

Micro- and nanoplastics unavoidably enter into organisms and humans as a result of widespread exposures through drinking waters, foods, and even inhalation. However, owing to the limited availability of quantitative analytical methods, the effect of nanoplastics inside animal bodies is poorly understood. Herein, we report a sensitive and robust method to determine the chemical composition, mass concentration, and size distribution of nanoplastics in biological matrices. This breakthrough is based on a novel procedure including alkaline digestion and protein precipitation to extract nanoplastics from tissues of aquatic animals, followed by quantitative analysis with pyrolysis gas chromatography-mass spectrometry. The optimized procedure exhibited good reproducibility and high sensitivity with the respective detection limits of 0.03 μg/g for polystyrene (PS) nanoplastics and 0.09 μg/g poly(methyl methacrylate) (PMMA) nanoplastics. This method also preserved the original morphology and size of nanoplastics. Furthermore, to demonstrate the feasibility of the proposed method, 14 species of aquatic animals were collected, and PS nanoplastics in a concentration range of 0.093-0.785 μg/g were detected in three of these animals. Recovery rates of 73.0-89.1% were further obtained for PS and PMMA nanospheres when they were spiked into the tissues of Zebra snail and Corbicula fluminea at levels of 1.84-2.12 μg/g. Consequently, this method provides a powerful tool for tracking nanoplastics in animals.

The Comparative Method is Not Macroevolution: Across-Species Evidence for Within-Species Process.

It is common for studies that employ the comparative method for the study of adaptation, that is, documentation of potentially adaptive across-species patterns of trait-environment or trait-trait correlation, to be designated as "macroevolutionary." Authors are justified in using "macroevolution" in this way by appeal to definitions such as "evolution above the species level." I argue that regarding the comparative method as "macroevolutionary" is harmful because it hides in serious ways the true causal content of hypotheses tested with the comparative method. The comparative method is a means of testing hypotheses of adaptation and their alternatives. Adaptation is a population-level phenomenon, involving heritable interindividual variation that is associated with fitness differences. For example, given heritable intrapopulational variation, more streamlined individuals in populations of fast-moving aquatic animals have higher locomotory efficiency and thus better survivorship and more resources directed to reproduction than less streamlined ones. Direct evidence consistent with this population-level scenario includes the observation that many unrelated species of fast-moving aquatic animals have similar streamlined shapes, an example of the comparative method. Crucial to note in this example is that although the data are observed across species, the comparative method for studying adaptation tests hypotheses regarding standard population-level natural selection with no content that can be construed as "macro." Even less "macro," individual-level developmental dynamics can limit or bias the range of variants available for selection. Calling any of these studies "macroevolutionary" implies that some additional process is at work, shrouding the need to test adaptation hypotheses and study the range of variants that can be produced in development. [Adaptation; comparative method; constraint; macroevolution; optimality models; population biology.].

Enhancement of wastewater treatment with underwater light: Efficiency and micro-ecosystem alterations in the open aerobic reactor of living machine

The source separation and decentralised treatment technology for domestic wastewater is an important method to improve sewage treatment rates and water reuse. The Living Machine (LM) system is a widely applied decentralised domestic wastewater treatment technology. In order to enhance the black water (toilet water) treatment performance, an underwater lamp was placed in the open aerobic reactor of the LM system, and treatment efficiency and micro-ecosystem changes with different light intensities were studied in this research. Compared to the control reactor (C), removal efficiencies of ammonia, total nitrogen (TN), and total phosphorus (TP) were increased from 22.07%, 16.03%, and 13.81% to 42.20%, 22.82%, and 17.20%, respectively, in the underwater light reactor (L) with an average intensity of 2083.00 LX, and COD removal was not obviously effected. The species and numbers of algae and the species of zooplankton and other aquatic animals were increased sharply in L, but their number did not fit a linear relation with light intensity. The bacteria group was prominently changed in L, whereas Malikia_spinosa, Emticicia_sediminis, and Rhodocyclaceae_bacterium_MORI13 were increased, and Rhodocyclaceae_bacterium_ICHIDE18 was obviously decreased. Although underwater illumination enhanced the wastewater reactor performance of the LM open aerobic reactor, further research is needed to learn more about the process optimization and relative mechanism.

The First Detection of Koi Herpesvirus (CyHV3) in Migratory Wild Ducks in North America.

A viromics study on the intestinal contents of migratory wild ducks of the genera Anas, Mareca, Spatula, and Oxyura during their winter stay in Mexico showed the presence of the virus family Alloherpesviridae. The genus Cyprinivirus is part of this family and includes cyprinid herpesvirus 3 (CyHV3). This is the etiological agent of the lethal disease known as koi herpesvirosis, which affects different strains of Common Carp Cyrprinus carpio. In this study, samples of the contents of 87 wild duck intestines were analyzed by endpoint PCR, of which 7 samples were positive for the amplification of the TK gene fragment corresponding to CyHV3. These results contribute to the knowledge about the spread of this virus to other species of aquatic animals in areas where fish and ducks coexist.

Responses of aquatic organisms to cyanobacteria and elodea in microcosms

The aim of the work was to investigate the effect of cyanobacteria and elodea on population characteristics (abundance, biomass, fecundity) and “health” indicators (embryo status, heart rate and thermal resistance) of aquatic invertebrates in microcosms with controlled conditions. In July-August 2018, four treatments with environmental conditions of the coastal zone of the Rybinsk Reservoir during the period of cyanobacterial bloom were modeled. Mass species of plankton (with 80% dominance of large Daphnia longispina) and benthic animals (Unio pictorum, Gmelinoides fasciatus, Asellus aquaticus) and Elodea canadensis were placed in microcosms. In treatments with cyanobacteria, the toxic microcystins-LR were detected (24-53% of the sum of toxins, or 6,6-66,5 µg/l). The cyanobacteria Aphanizomenon flos-aquae, Microcystis aeruginosa and Gloeoitrichia spp. affected the structure of plankton reflecting in a decrease in the amount of green algae and an increase in the abundance of small crustaceans. Under the influence of cyanobacteria, variables of benthic animals differed significantly from control treatment, including a reduced level of thermal resistance of mollusks and amphipods, an increased recovery time of the heart rate after loading (salinity test) in mollusks, a decrease in individual fecundity, and an increase in the frequency of malformations and embryo mortality in amphipods. The presence of elodea enhanced these effects. Thus, the mass development of cyanobacteria and elodea affects the physiological status of sensitive species of aquatic animals, reducing their adaptability to natural stresses and worsening the quality of offspring.

Fish Nutrient Composition: A Review of Global Data from Poorly Assessed Inland and Marine Species (P04-139-19)

ObjectivesOur understanding of the nutrient contribution of fish to human diets relies on nutrient composition data for a starkly limited number of fish species. Yet particularly for the most nutritionally vulnerable fish consumers around the world, fish consumption includes a wide diversity of fish species whose nutrient composition data is disparate, poorly compiled, or unknown. To address the gap in understanding fish nutrient composition data, we reviewed the literature with an emphasis on small indigenous species of fish that are missing from global databases. MethodsWe conducted a systematic review by searching fish* AND *nutri* composition in 3 databases (EBSCO Host Agricola, Web of Science, and Web of Science using cabicode Food Composition and Quality) and one research journal (Journal of Food Composition and Analysis, search for fish*). We screened 3627 articles returned by search results and retained 81 articles containing 985 entries of nutrient composition data for fish and aquatic species (inclusive of duplicates). We compiled a database with all available information on fish nutrient composition (i.e., macronutrients, micronutrients, fatty acids, amino acids) and heavy metals (e.g., lead, mercury) on global fish and other aquatic animals, including both inland and marine species. ResultsWe highlight fish and other aquatic animal species within our database that are particularly high in nutrients of global importance, including iron, zinc, calcium, vitamin A, and docosahexaenoic acid (DHA), and examine when a serving of fish and other aquatic animals can fill critical nutrient needs for pregnant and lactating women and children under two (Figure 1). ConclusionsBy collating the available nutrient composition data on small indigenous species of fish and other aquatic animals, we provide a resource for fisheries and nutrition researchers, experts, and practitioners to better understand these critical species and include them in food-based programs and policies. Funding SourcesCornell University’s Atkinson Center for a Sustainable Future (to KJF) and the International Fund for Agriculture Development in partnership with WorldFish (to KB and SHT). Supporting Tables, Images and/or Graphs▪▪▪▪▪