Adult Grass Research Articles

Histidine is effective in promoting muscle growth and protein deposition: In vivo and in vitro experimental models of grass carp (Ctenopharyngodon idella)

For aquatic animals, histidine is an essential amino acid. This study examined its impact on muscle growth and protein deposition in grass carp, both in vivo and in vitro, and explored the underlying mechanisms. A total of 450 grass carp (594.63 ± 0.68 g) were assigned randomly to six groups of three replicates for each group that was fed with six diets containing 1.08 (basal diet), 2.91, 5.87, 8.83, 11.78, and 14.79 g/kg histidine for 63 d. Results indicated that based on PWG and muscle protein content, the histidine demands of adult grass carp were 8.94 (34.12 g/kg protein) and 8.54 g/kg diet (32.60 g/kg protein), respectively. Optimal histidine promoted myofiber hypertrophy, which could be correlated with cell proliferation-associated proteins [PCNA, E2F4 and Cyclin (B, D and E)] and myogenic regulators (MyoD, MyoG, MyHC and Myf6). Optimum histidine enhanced protein deposition, which could be correlated with the facilitation of protein synthesis (IGF-1/PI3K/AKT/TOR) as well as the suppression of ubiquitin-proteasome system and autophagy-lysosome system to inhibit protein degradation. Furthermore, optimal histidine raised muscle bound amino acid content and amino acid chemistry scores, thereby increasing muscle nutritional value.

From antioxidant to muscle enhancer: Resveratrol's role in grass carp (Ctenopharyngodon idella) nutrition

Resveratrol (RES), a type of stilbenoid, is known for its significant role in enhancing meat quality by virtue of activating SIRT1. Against this backdrop, this study explored the impact of resveratrol on various parameters influencing flesh quality in adult grass carp. Over a span of 9 weeks, adult grass carp were fed diets with five different levels of RES (0, 40, 80, 160 and 320 mg/kg). Our findings demonstrated that resveratrol supplementation had no adverse effects on the growth performance of adult grass carp. Notably, adding the right amount of resveratrol to the diets caused the protein and amino acid levels, pH24 h, and shear force of grass carp muscle to rise. Additionally, it led to a reduction in cooking loss and lactic acid content. Moreover, Addition of appropriate levels of resveratrol to the feed promoted myofiber hyperplasia in adult grass carp, which may be achieved by stimulating adult myoblast proliferation and differentiation. Subsequent studies have found that appropriate levels of resveratrol inhibit endoplasmic reticulum stress (ERS), which promotes muscle fiber development. Additionally, resveratrol was found to lead to an increase in unsaturated fatty acid (UFA) content in grass carp muscle. This alteration in fatty acid composition could be attributed to changes in fatty acid transport, synthesis, and catabolism. According to muscle protein carbonyl level, muscle protein content and frequency of muscle fibers smaller than 20 μm, the optimum resveratrol supplementations of grass carp were 178.33, 198.33 and 226.67 mg/kg.

Exploring the dietary strategies of phenylalanine: Improving muscle nutraceutical quality as well as muscle glycogen and protein deposition in adult grass carp (Ctenopharyngodon idella)

Muscle is the main edible part of bony fish. The purpose of this study was to investigate the influences of phenylalanine (Phe) on muscle quality, amino acid composition, fatty acid composition, glucose metabolism, and protein deposition in adult grass carp. The diets at 2.30, 4.63, 7.51, 10.97, 13.53, and 17.07 g/kg Phe levels were fed for 9 weeks. The results manifested that Phe (10.97–13.53 g/kg) increased the pH of the fillets and decreased muscle cooking loss and lactic acid content; Phe (7.51–17.07 g/kg) improved the composition of the fillets in terms of flavor (free) amino acids, bound amino acids (especially EAA), and fatty acids (especially EPA and DHA); Phe (7.51–13.53 g/kg) increased muscle glycogen content (possibly related to the AMPK signaling pathway) and muscle protein deposition (possibly related to IGF-1/4EBP1/TOR and AKT/FOXOs signaling pathways). In conclusion, a diet with appropriate Phe levels could improve fillet quality.

Hypoxia leads to gill endoplasmic reticulum stress and disruption of mitochondrial homeostasis in grass carp (Ctenopharyngodon idella): Mitigation effect of thiamine

Hypoxia in water environment is one of the important problems faced by intensive aquaculture. Under hypoxia stress, the effects of dietary thiamine were investigated on grass carp gill tissue damage and their mechanisms. Six thiamine diets with different thiamine levels (0.22, 0.43, 0.73, 1.03, 1.33 and 1.63 mg/kg) were fed grass carp (Ctenopharyngodon idella) for 63 days. Then, 96-hour hypoxia stress test was conducted. This study described that thiamine enhanced the growth performance of adult grass carp and ameliorated nutritional status of thiamine (pyruvic acid, glucose, lactic acid and transketolase). Additionally, thiamine alleviated the deterioration of blood parameters [glutamic oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), glucose, cortisol, lactic dehydrogenase (LDH), erythrocyte fragility, and red blood cell count (RBC count)] caused by hypoxia stress, and reduced reactive oxygen species (ROS) content and oxidative damage to the gills. In addition, thiamine alleviated endoplasmic reticulum stress in the gills, which may be related to its inhibition of RNA-dependent protein kinase-like ER kinase (PERK)/eukaryotic translation initiation factor-2α (eIF2α)/activating transcription factor4 (ATF4), inositol-requiring enzyme 1 (IRE1)/X-Box binding protein 1 (XBP1) and activating transcription factor 6 (ATF6) pathways. Furthermore, thiamine maintaining mitochondrial dynamics balance was probably related to promoting mitochondrial fusion and inhibiting mitochondrial fission, and inhibiting mitophagy may involve PTEN induced putative kinase 1 (PINK1)/Parkin-dependent pathway and hypoxia-inducible factor (HIF)-Bcl-2 adenovirus E1B 19 kDa interacting protein 3 (BNIP3) pathway. In summary, thiamine alleviated hypoxia stress in fish gills, which may be related to reducing endoplasmic reticulum stress, regulating mitochondrial dynamics balance and reducing mitophagy. The thiamine requirement for optimum growth [percent weight gain (PWG)] of adult grass carp was estimated to be 0.81 mg/kg diet. Based on the index of anti-hypoxia stress (ROS content in gill), the thiamine requirement for adult grass carp was estimated to be 1.32 mg/kg diet.

The influence of eugenol, benzocaine and ice water on the welfare of adult grass carp (Ctenopharyngodon idella).

The aim of this study was to evaluate the effects of eugenol, benzocaine, and ice water during the sedative, anesthetic or euthanasia processes on the welfare of adult grass carp (Ctenopharyngodon idella). The experimental design was randomized and the animals were divided into eight groups. Sixty-two animals underwent an acclimation period. The neutral group used to obtain basal data of grass carp were not subjected to treatments, but anesthetized to collect blood samples and euthanized by medullary section. The others seven groups were submitted to seven treatments with eight repetitions (control group; ethanol; eugenol 50 mgL-1, eugenol 250 mgL-1, benzocaine 100 mgL-1, benzocaine 300 mgL-1, and ice water 2:1), their behavior was observed. Blood samples was collected and then euthanized by medullary sectioning. Biometric data were measured and a part of the liver was collected for hepatic glycogen analysis. There was a statistically significant difference in the time required to reach the anesthetic stage between the groups (p < 0.01). Benzocaine and eugenol at the higher concentration provided the fastest responses to sedatives and anesthetics, respectively. The animals subjected to higher anesthetic concentrations reached stage five and did not return from anesthesia, therefore, benzocaine and eugenol were effective euthanizing agents. Benzocaine at the lowest concentration showed the highest concentrations of glucose and cortisol (p < 0.05). Although benzocaine at 100 mgL-1 concentrations is widely used as an anesthetic in fish, this study demonstrated its use as a stressor agent. Basal data of grass carp for stress parameters are presented for the first time.

Improvement of flesh quality, muscle growth and protein deposition in adult grass carp (Ctenopharyngodon idella): The role of tryptophan

The muscle is the main edible part of the animal trunk. Previous studies have shown that tryptophan is the limiting amino acid for protein synthesis. This study investigated whether dietary tryptophan could improve growth performance, flesh quality, muscle growth, and protein deposition in adult grass carp (Ctenopharyngodon idella). 450 grass carp (671.31 ± 1.66 g) were fed with six diets (iso‑nitrogenous) with different concentrations of tryptophan (0.25, 1.66, 3.12, 4.69, 5.95, and 7.61 g/kg diet) for 9 weeks. The results revealed that the optimal tryptophan levels (3.12 or 4.69 g/kg diet) increased feed intake (FI), feed efficiency (FE), percent weight gain (PWG), and specific growth rate (SGR) compared with the deficient group (0.25 g/kg diet), indicating that tryptophan improved the growth performance of adult grass carp. The optimal tryptophan levels increased the muscle contents of protein, lipid, protein-bound amino acids, free amino acids (FAA), pH24h, and shear force; improved the fatty acid (FA) profile in muscle; and reduced cooking loss and lactate content, suggesting that tryptophan improved the flesh quality of adult grass carp. The optimal tryptophan levels increased the myofiber diameter, frequency of >50 μm diameter fiber, mRNA levels of MRFs (MyoD, MyoG, Mrf4, and Myf5), and decreased the mRNA levels of MSTN in muscle, indicating that tryptophan promoted muscle growth in adult grass carp. We further found that the promotion of muscle protein deposition by dietary tryptophan may be related to protein synthesis, ubiquitin-proteasome, and autophagic lysosomal pathways. We discovered that dietary tryptophan increased the mRNA abundances of IGF-1, PI3K, AKT, TOR, and S6K1 and decreased the mRNA abundances of 4EBP1, FOXO1a, FOXO3a, MAFBX, MuRF1, UB, ULK1, Beclin1, ATG5, ATG12, p62, LC3–1, and LC3–2, thereby promoting muscle protein deposition in adult grass carp. The above results showed that dietary tryptophan enhanced growth performance, flesh quality, muscle growth, and muscle protein deposition in adult grass carp. Moreover, using broken line regression, the tryptophan requirement of adult grass carp was estimated to be 3.02 g/kg diet (11.64 g/kg protein) based on PWG.

An emerging role of arecoline on growth performance, intestinal digestion and absorption capacities and intestinal structural integrity of adult grass carp (Ctenopharyngodon idella)

Arecoline is an alkaloid with important pharmacological effects in the plant areca nut, which has been demonstrated to be an agonist of muscarinic receptors (M receptor). This study explored the influences of dietary arecoline on growth performance, intestinal digestion and absorption abilities, antioxidant capacity, and the apical junction complex (AJC) of adult grass carp (Ctenopharyngodon idella). Adult grass carp (608 to 1512 g) were fed at 6 graded levels of dietary arecoline (0, 0.5, 1.0, 1.5, 2.0, and 2.5 mg/kg diet) for 9 weeks. The results suggested that appropriate dietary supplementation of arecoline (1.0 mg/kg) increased growth parameters and intestinal growth in adult grass carp (P < 0.05), enhanced digestion and absorption capacities (P < 0.05), up-regulated muscarinic receptor 3 (M3) mRNA level (P < 0.05), increased the content of neuropeptide fish substance P (P < 0.05), improved antioxidant capacity by activating the Keap1a/Nrf2 signaling pathway (P < 0.05), reduced intestinal mucosal permeability (P < 0.05), and increased mRNA levels of tight junction (TJ) and adherent junction AJ-related proteins in fish by inhibiting the RhoA/ROCK signaling pathway (RhoA/ROCK/MLCK/NMII) (P < 0.05). In addition, the appropriate arecoline supplementation for adult grass carp was determined to be 1.20, 1.21, 1.07, and 1.19 mg/kg based on percentage weight gain, lipase activity, serum diamine oxidase, and protein carbonyl, respectively. Overall, to the best of our knowledge, we investigated for the first time the effects and possible mechanisms of dietary arecoline on intestinal digestive and absorptive capacities and structural integrity in fish and evaluated the appropriate level of supplementation.

Field evaluation of electrofishing response thresholds for adult Grass Carp

AbstractObjectiveOptimal electrofishing waveforms and parameters have been established for juvenile Grass Carp Ctenopharyngodon idella in controlled laboratory trials, but effective settings for adult Grass Carp in riverine systems remain to be determined. This work builds upon existing research by making opportunistic use of data collected in the Cuyahoga River, Ohio, to refine power standards for boat electrofishing that is used to target adult Grass Carp.MethodsOver 12 days of boat electrofishing surveys, we used a gradient of voltage settings at various ambient water conductivities to generate an electrofishing goal table for adult Grass Carp.ResultOur target power was 3550 W (1447–6507 W) higher, on average, than the target power recommended in previous studies for coolwater and warmwater fish species with 60 Hz. Results also show that a 40‐A control box is inadequate in locations where ambient water conductivities exceed 576 μS/cm and when power is limited.ConclusionRefining power standards for boat electrofishing that targets Grass Carp may increase catch rates to levels needed to suppress populations in the Great Lakes region and North America.

Application of enzymatically treated Artemisia annua L. on adult grass carp (Ctenopharyngodon idella): Improved growth performance, intestinal antioxidant capacity and apical junctional complex

The present study evaluated the effects of enzymatically treated Artemisia annua L. (EA) on the growth performance, intestinal antioxidant capacity, and apical junctional complex (AJC) of adult grass carp. In this experiment, 375 healthy grass carp (initial body weight 673.96 ± 1.24 g) were selected and randomly divided into 5 treatments, and fish in each group were fed diets with different levels of EA (0, 400, 800, 1200, and 1600 mg/kg) 9 weeks. The results showed that compared with the control group (0 mg/kg EA diet), the EA supplementation in the diet increased the percentage of weight gain (PWG), specific growth rate (SGR), and feed intake (FI) (P < 0.05), indicating that dietary EA supplementation improved the growth performance of adult grass carp. The dietary EA supplementation also enhanced the digestion and absorption ability of adult grass carp, which might be reflected by improving the activities of hepatopancreas digestive enzymes (trypsin, chymotrypsin, lipase, and amylase) and intestinal brush border enzymes (alkaline phosphatase, Na+/K+-ATPase, and γ-glutamyl transpeptidase), but EA did not affect the creatine kinase enzyme activity. Meanwhile, we explored the effect of dietary EA addition on the structural integrity of the grass carp intestine. We observed that dietary EA supplementation improved the antioxidant capacity of the intestine which be reflected by increasing the activities levels of superoxide dismutase (SOD) and catalase (CAT), which might be related to the binding protein Keap1a (not Keap1b)/ NF-E2-related factor-2 (Nrf2) signaling pathway. In addition, dietary EA supplementation enhanced the integrity of AJC by increasing the mRNA levels of intestinal tight junction proteins (TJs) (except claudin 11, claudin 12, claudin 15a) and adhere junction proteins (AJs) (E-cadherin, α-catenin, β-catenin, nectin, and afadin), which might be related to the Rho family GTPases (RhoA)/ Rho-associated protein kinase (ROCK)/ myosin light chain kinase (MLCK) signaling pathway. Collectively, dietary EA supplementation improved growth performance, digestion and absorption ability, and intestinal structural integrity in grass carp, which were associated with the activation of related signaling pathways and regulatory factors. Finally, by the growth indicator percent weight gain (PWG) and intestinal oxidative damage index protein carbonyl (PC), the optimum amounts of EA supplementation of adult grass carp (673–1726 g) were assessed to be 808.09 and 730.38 mg/kg diet, respectively.

Grass Carp Reproduction in Small Tributaries of Harry S. Truman Reservoir, Missouri: Implications for Establishment in Novel Habitats

AbstractSubstantial work has been conducted to estimate the river length required for recruitment of invasive Grass Carp Ctenopharyngodon idella and bigheaded carps (Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix); however, the distance upstream and size of stream required for spawning remain unclear. Adult Grass Carp are regularly captured in Harry S. Truman Reservoir, Missouri, although there have been only unconfirmed sightings of Silver Carp. Fertile diploid Grass Carp are used legally for vegetation control in Missouri; however, it is uncertain whether Grass Carp in Harry S. Truman Reservoir are the result of natural reproduction or escapees. We used ichthyoplankton tows and environmental DNA (eDNA) to investigate which carp species were present in the reservoir basin and to determine whether these carps were spawning in reservoir tributaries. Grass Carp eggs were collected in four of five tributaries during June 2014. We did not detect eggs, larvae, or eDNA of Bighead Carp or Silver Carp. The occurrence of Grass Carp eggs generally coincided with rapid increases in discharge and turbidity. These tributaries may be the smallest rivers worldwide in which spawning of Grass Carp has been documented. We infer from the developmental stages captured and the distance from the reservoir that sufficient river length exists for egg survival. These results have broad implications concerning the establishment of Grass Carp in other novel habitats, including other reservoirs and lake basins, smaller rivers, and the Laurentian Great Lakes ecosystem.

Effects of salinity treatment on muscle quality and off‐flavour compounds of grass carp ( Ctenopharyngodon idella ) and black carp ( Mylopharyngodon piceus )

To investigate the effects of short-term salinity treatment on muscle quality and earthy and musty off-flavour compounds of freshwater fish, adult grass carp (1.25 ± 0.25 kg) and black carp (1.50 ± 0.30 kg) were reared at water salinities of 0‰, 5‰ and 7.5‰for 48 h. Muscle nutrients, amino acid, and fatty acid contents, texture properties, and earthy and musty off-flavour compounds were then determined. The content of total amino acid (TAA), Lys, Arg and essential amino acid index (EAAI) in the muscle of C7.5 group were elevated significantly compared with that in the control group (p < 0.05). The content of delicious amino acids (DAA) and EAAI in the muscle of M7.5 group was significantly higher than M0 and M5 groups (p < 0.05). The fatty acid content of the muscle was affected by salinity. In grass carp, the saturated fatty acid (SFA) content level was decreased significantly in the C5 and C7.5 groups (p < 0.05), while the monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) content levels were increased significantly in the C5 and C7.5 groups (p < 0.05). The ratio of n3/n6 PUFA increased significantly in the C7.5 group (p < 0.05). The PUFA content and the n3/n6 PUFA ratio were increased significantly in the M7.5 group (p < 0.05). With increasing salinity, the relative content levels of volatile compounds causing earthy and musty off-flavour in muscle were decreased significantly in 5‰ and 7.5‰ salinity groups both grass carp and black carp (p < 0.05). The textural properties of muscle, such as hardness, springiness, gumminess and chewiness, were improved in the C7.5 and M5 groups. These results suggest that a short-term salinity treatment in freshwater fish prior to selling can effectively improve muscle quality and decrease the content of earthy and musty off-flavour compounds, with ideal salinities of 5‰ or 7.5‰ for grass carp and 7.5‰ for black carp.

Demographic and Trophic Analysis of Adult Grass Shrimp (Palaemonetes pugio) from Living Shoreline and Natural Tidal Marshes in the Chesapeake Bay

With extensive and ongoing human development in coastal areas, effective shoreline-protection strategies against erosion and rising sea level that also provide natural ecosystem services will become increasingly important. Constructed living shoreline marshes can serve as successful management solutions when implemented correctly, but studies comparing these created estuarine habitats to their natural marsh counterparts are needed to assess their ecological functionality. We compared adult Palaemonetes pugio (Daggerblade Grass Shrimp) population demographics and diets from 13 pairs of living shoreline and natural marsh sites in the southwestern portion of the Chesapeake Bay. No significant differences were observed in demographics including abundance, weight, length, number of gravid females, and egg abundance and quality. Gut-content analysis detected significantly more terrestrial debris in shrimp from living shorelines, but the omnivorous dietary needs appeared met in all marsh sites. Overall, shrimp populations differed more among site pairs from different shorescape settings than between created and natural marshes from the same settings, suggesting that living shorelines are approaching ecosystem functionality similar to natural marsh habitats. However, the observed negative effect of agricultural land use on shrimp abundance and the discovery of microplastics in gut contents from all sites sampled indicate the need for further consideration of human impacts in both constructed and natural coastal habitats.

鄱阳湖水利枢纽工程建设对草鱼江湖洄游潜在的影响

鄱阳湖是长江四大家鱼索饵、育肥的重要场所, 近年来鄱阳湖出现了枯水季水位严重降低、枯水期延长、湿地面积缩小的现象。为解决鄱阳湖水资源、水文、水生态等问题, 建议在鄱阳湖入江水道兴建控制闸水利枢纽。然而, 拟建的水利枢纽工程将打破鄱阳湖与长江的天然连通性, 可能会对四大鱼类洄游过程产生影响。通过构建二维和三维水动力模型, 分析鄱阳湖水利枢纽建设后入江水道与枢纽洄游通道的水动力学特征, 结合实验和文献获得的草鱼幼鱼和成鱼游泳能力参数, 阐明了枢纽建设对草鱼洄游的影响。结果表明: 在设计调度模式下, 草鱼幼鱼入湖期间, 湖口段适宜通过天数达到83.74%以上, 说明湖口及入江水道的水动力条件对洄游的影响较小, 同时, 枢纽工程处在过鱼高峰期仍能保持较高的过闸效率; 草鱼成鱼出湖期间, 丰、平水年闸前水动力条件对洄游的影响较小, 仅在枯水年闸前流速几乎静止, 草鱼适宜出湖天数偏低。在该调度模式下, 水利枢纽建设运行后鄱阳湖整体水动力条件能够满足草鱼洄游需求。目前设计的鱼道在高、低水位时期均出现局部流速过大的现象, 不满足过鱼条件。从四大家鱼江湖洄游的角度为鄱阳湖水利枢纽工程设计和运行提供科学参考。;Poyang Lake serves as the main feeding and fattening venue for the four major Chinese carps. In recent years, Poyang Lake has experienced a severe drop in water level during the dry season, prolonged dry season, and reduced wetland area. To tackle the problem of water resources, hydrology and water ecology in Poyang Lake, it is suggested to build a hydro-junction project which is proposed to be located at the channel connecting the Poyang Lake and the Yangtze River. Yet the to-be-built Poyang Lake Hydro-junction Project would impede the natural connection between Poyang Lake and the Yangtze River. The migration passage of the four major Chinese carps may be affected. To study the potential impact of the prospective hydro-junction project on the migration of grass carp, analysis was conducted on the hydrodynamic characteristics of the migration channel after the construction of Poyang Lake Hydro-junction Project using two-dimensional and three-dimensional hydraulic models. The swimming ability of grass carp was determined through experiment and literature review. According to the study results, more than 83.74% of the days suitable for fish passage at the entrance to the lake. The hydrodynamic conditions at the entrance and the channel into the Yangtze River had an insignificant impact on the fish migration at the time when the juvenile grass carps entered the lake. Meanwhile, the gate chamber of hydro-junction project could still maintain a high passing efficiency during the peak period of fish migration. While under the designed scheduling mode, the hydrodynamic conditions in front of the hydraulic construction had little effect on fish migration in the years of wet and normal, but the days that were favorable for the fish departure from the lake decreased in dry years caused by almost static velocity in front of the hydraulic construction when the adult grass carps left the lake. The overall hydrodynamic conditions of Poyang Lake could meet the needs of the grass carp migration during the operation period of the Poyang Lake Hydro-junction Project. However, the current design of the fishway of the Poyang Lake Hydro-junction Project suffered the excessive flow velocity in some parts during high and low water level period, which dissatisfied the required passage conditions based on fish swimming ability under the existing scheduling mode. This study was expected to provide a scientific reference for the design and operation of the Poyang Lake Hydro-junction Project from the perspective of river-lake migration of the four major Chinese carps.

Establishment of a cell line from swim bladder of the Grass carp (Ctenopharyngodon idellus) for propagation of Grass Carp Reovirus Genotype II

A cell line was established from swim bladder of the Grass carp (Ctenopharyngodon idellus) (CiSB), which was permissive for infection and propagation of Grass Carp Reovirus (GCRV). CiSB cells displayed optimal growth at 27 °C using M199 medium containing 10% fetal bovine serum and a fibroblastic-like morphology. Karyotype analysis revealed that the average diploid chromosome number was 52 in 58% of cells at passage 60 compared to the wild type Grass carp cells (2n = 48). Infection with GCRV II isolate Hunan1307 was tracked by immunofluorescence and virus titration assay. The virus titer reached 105.2 TCID50/mL on 7th days post infection (dpi). Healthy adult Grass carp that were challenged with the virus propagated onto CiSB cells, displayed the typical symptoms and histopathological changes of Grass carp hemorrhagic disease (GCHD). Therefore, the CiSB cells can be used to propagate GCRV II and serve as a useful tool to study the pathogenesis of GCHD.

Validation of the model-predicted spawning area of grass carp Ctenopharyngodon idella in the Sandusky River

Spawning of grass carp, Ctenopharyngodon idella, in the Great Lakes basin was verified when eight fertilized eggs were collected in the Sandusky River, a tributary to Lake Erie, in 2015. Using a fluvial drift model (FluEgg) and simulation modeling, researchers predicted the fertilization location for those eggs was 3.8 ± 1 km (95% credible interval, CI) downstream of Ballville Dam. In June 2018, simultaneous collection of fertilized eggs and adults within the model-predicted spawning area provided the opportunity to verify the fertilization location. We used estimated developmental time (Dt) of eggs calculated from developmental stages, water temperature, and an equation that predicts Dt from cumulative thermal units experienced by developing eggs, in two analyses. First, we regressed Dt versus location of capture and solved that equation for developmental time of 0 hrs (Dt0) to estimate fertilization location. Second, we used Dt in the Fluvial Drift Simulator (FluEgg) to simulate 23 scenarios representative of drift conditions throughout the spawning event using the model-predicted spawning area and the site of Ballville Dam as potential spawning locations. Regression analysis placed the mean fertilization location 3.36 km (95% CI 2.27, 4.24) downstream of the site of Ballville Dam, within the model-predicted spawning area. Drift models demonstrated the model-predicted spawning area was best supported. Histograms of fertilization times overlapped with capture times by boat electrofishing of diploid adult grass carp in the model-predicted spawning area. This suite of analyses confirms the model-predicted spawning area and validates the methodology used to locate it.

A novel formulation of budesonide nasal spray (Budesolv 10) potentiates clinical performance in grass pollen allergic patients

Abstract Objective Purpose of this DBPC study was to evaluate onset of action and non-inferiority of a novel low dose aqueous solution of Budesonide (“Budesolv 10μg”) to Rhinocort® aqua 64μg (RA) in adult grass pollen allergic patients. Methods Budesonide, a poorly water-soluble corticosteroid, currently marketed as suspension, was reformulated to enhance solubility and local concentration on the target mucosa. Subjects received Budesolv, the market comparator RA and placebo once daily for 8 days. Allergic symptoms were induced by 6h grass pollen challenges in the Vienna Challenge Chamber at days 1 and 8 of each treatment period. First dose was applied after 1:45h to evaluate onset of action of either treatment. Nasal, ocular, asthma symptoms and objective measures of nasal secretion and nasal obstruction were evaluated. A 95% confidence interval (CI) was calculated for difference in means between active treatments. Non-inferiority was stated if the upper limit of the CI did not exceed 115% of the reference. Onset of action was defined as first time point when the difference in nasal symptoms change from baseline between active treatment and placebo was p&amp;lt;0.05. Results 75 patients concluded the study per protocol. The primary endpoint (TNSS; sum of obstruction, itch, sneeze and rhinorrhoea) was met proving non-inferiority of Budesolv compared to RA. A significant difference between Budesolv and placebo was shown for TNSS 2.45 h and for total asthma score 2 h after first dose. On day 8 Budesolv 10μg was significantly better than placebo for all parameters evaluated. Conclusion Non-inferiority of Budesolv compared to Rhinocort® was shown on day 8 of treatment. Early onset of action within 3h after first dose was evident for Budesolv only.

Seasonal emergence of benign epidermal tumor in farm-reared adult grass carp (Ctenopharyngodon idella) caused by lymphocystis disease virus at Uttarakhand, India

From 2017‐2019, during the winter months (November–January), epidermal papilloma like benign tumor was observed in farm-reared adult grass carp, Ctenopharyngodon idella at the northern part of India. An investigation was undertaken to establish the causative agent of this epizootiology. Based on the clinical signs and ineffectiveness of antibiotics to control this disease, viral infection was suspected. A primer was designed to PCR amplify the partial DNA polymerase gene of lymphocystis disease virus (LCDV) from the tumor of moribund grass carp, which yielded 460 bp amplicon. After sequencing this 460 bp amplicon, the viral agent from the tumor of grass carp was identified as lymphocystis disease virus and given strain designation LRI-18 (Genbank accession number-MK347473). Phylogenetic analysis based on the nucleotide sequence of DNA polymerase gene of LCDV revealed the close association of LCDV LRI-18 to LCDV strain from Israel with 99.0% and 96.5% nucleotide and amino acid sequence identity, respectively. LCDV LRI-18 form single (type A; 0.5–2.0 μm) or multiple (type B; 0.5–2.0 μm) intracytoplasmic inclusion bodies on lymphocystis and erythrocyte cells of infected grass carp. Transmission Electron Microscopy (TEM) of blood revealed the presence of enveloped icosahedral virions of approximately 280 nm in diameter with electron dense core and an outer capsid. Histopathological study of various organs of LCDV infected grass carp revealed extensive hypertrophy and fusion of secondary gill lamellae, focal hemorrhage in the eye, pyknotic nuclei in the liver, inflammation in the myocardium, fused villi of intestine and degeneration of the glomeruli in the kidney. Experimental infection by a dip to grass carp fingerlings (average body weight 4.4 ± 0.9 g) using 0.45 μm filtered LCDV crude suspension did not reproduce the disease, and also no mortality were observed. This is the first report of the occurrence of lymphocystis disease in grass carp in India.

A Comparison of Grass Carp Population Characteristics Upstream and Downstream of Lock and Dam 19 of the Upper Mississippi River

Abstract Grass Carp Ctenopharyngodon idella have been intentionally stocked for aquatic vegetation control across the Midwestern United States for several decades. During the 1970s, escapement of Grass Carp into the Missouri River facilitated their naturalization into much of the Mississippi River basin, including the Upper Mississippi River. Lock and Dam 19 (LD19) in Keokuk, Iowa, is a high-head dam that represents a focal point for naturalized Grass Carp management where populations may differ between upstream and downstream pools as result of limited upstream migration, but potential differences between populations have yet to be evaluated to the best of our knowledge. The objective of this study was to compare the relative abundance, size structure, condition, growth, and recruitment variability of Grass Carp collected upstream and downstream of LD19. We sampled Grass Carp monthly (April–October) during 2014 and 2015 from four locations in the Des Moines River (downstream of LD19) and five locations throughout the Skunk, Iowa, and Cedar rivers (upstream of LD19) using boat electrofishing and trammel net sets. We captured 29 Grass Carp upstream of LD19 compared with 179 individuals captured downstream. Trammel nets only captured Grass Carp downstream of LD19; trammel net catch per unit effort upstream of LD19 was low and ranged from 0.0 to 8.0 fish/net lift (mean ± SE = 0.39 ± 0.13). Electrofishing catch per unit effort ranged from 0.0 to 22.7 fish/h (1.49 ± 0.30) and was higher downstream (2.42 ± 0.30) of LD19 than upstream (0.57 ± 0.07). Grass Carp downstream of LD19 tended to be smaller, younger, of lower body condition, had higher mortality rates, and were slower growing compared with those collected upstream and to populations documented in other systems. Understanding and monitoring adult Grass Carp population characteristics upstream and downstream of LD19 is necessary to determine how they may change in response to ongoing harvest efforts for invasive carps in these river reaches.

Movements and habitat choice of resident and translocated adult female Grass Snakes (Natrix natrix) during the egg-laying period

We used externally applied transmitters to study movements of female grass snakes (Natrix natrix) during the egg-laying period in a near-urban landscape in Sweden. Half of the studied snakes were r ...

Optimum Electrofishing Waveforms and Parameters to Induce Immobilization of Juvenile Grass Carp

AbstractGrass Carp Ctenopharyngodon idella, a nonnative species to North America, are known to cause negative impacts to aquatic habitats and aquatic communities. Numerous fisheries techniques have been used in an attempt to control or eradicate Grass Carp, including electrofishing. However, electrofishing efficiency for Grass Carp has been variable, and optimum electrofishing waveforms and parameters for inducing a capture‐prone response have not been determined. The objective of this study was to determine the optimum electrofishing waveforms and parameters to induce a capture‐prone response at various water temperatures and conductivities in juvenile Grass Carp in a controlled, laboratory setting. Results indicated that rectangular pulse waveforms with 60–100 Hz frequencies were most effective for immobilization of juvenile Grass Carp. While all duty cycles tested (20–48%) at these frequencies were effective we found that at 60 Hz and 80 Hz frequencies, 24% and 30% duty cycles, respectively, may be more effective. Water temperature was positively related to voltage gradient immobilization thresholds whereas ambient water conductivity and fish size were inversely related to voltage gradient immobilization thresholds. This study provides important information to those seeking to control, eradicate, or detect Grass Carp using electrofishing and provides a framework for future studies focusing on adult Grass Carp.