Effect of vertical slit turbulence on metabolism and swimming behavior of juvenile grass carp (ctenopharyngodon idella)

2017 ◽  
Author(s):  
Yuan Xi ◽  
Jiang Qing ◽  
Xu Meng ◽  
Tu Zhi-ying ◽  
Zhou Yi-hong ◽  
...  
Keyword(s):  
Laminar Flow ◽  
Turbulent Flow ◽  
Grass Carp ◽  
Swimming Behavior ◽  
Ecological Impacts ◽  
Ctenopharyngodon Idella ◽  
Fish Swimming ◽  
Vertical Slit ◽  
Grass Carp Ctenopharyngodon Idella ◽  
Test Fish

AbstractBaffles were incorporated into the swim chamber of a flume-type swimming respirometer, and the effect of vertical slit turbulence on the swimming behavior and metabolism of juvenile grass carp were investigated. Results showed a significant lower TBF in turbulent flow than in laminar flow (p< 0.05). However, differences in TBF at different inlet velocities were not significant (p> 0.05), whether the fish passed through the baffles or not. In turbulent flow, the residence time ratios of test fish at different flow zone were low water velocity > medium velocity > high velocity. Oxygen consumption rate (MO2) increased with flow velocity and was higher in turbulent flow than in laminar flow. Further, the speed exponent c, in turbulent flow, was significantly higher than in laminar flow, indicated a decrease swimming efficiency. This study of fish swimming in turbulent flow extends knowledge of fish ecology and provides data for guiding the design of hydrokinetic turbulent where needed, so preventing ecological impacts.

scholarly journals Quantifying the Response of Grass Carp Larvae to Acoustic Stimuli Using Particle-Tracking Velocimetry

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 603
Author(s):  
Hojung You ◽  
Rafael O. Tinoco
Keyword(s):  
Particle Tracking ◽  
Grass Carp ◽  
Particle Tracking Velocimetry ◽  
Quantitative Imaging ◽  
Functional Relation ◽  
Acoustic Signals ◽  
Ecological Impacts ◽  
Ctenopharyngodon Idella ◽  
Response Ratio ◽  
Larval Behavior

Acoustic deterrents are recognized as a promising method to prevent the spread of invasive grass carp, Ctenopharyngodon idella (Valenciennes, 1844) and the negative ecological impacts caused by them. As the efficacy of sound barriers depends on the hearing capabilities of carp, it is important to identify whether carps can recognize acoustic signals and alter their swimming behavior. Our study focuses on quantifying the response of grass carp larvae when exposed to out-of-water acoustic signals within the range of 100–1000 Hz, by capturing their movement using particle-tracking velocimetry (PTV), a quantitative imaging tool often used for hydrodynamic studies. The number of responsive larvae is counted to compute response ratio at each frequency, to quantify the influence of sound on larval behavior. While the highest response occurred at 700 Hz, we did not observe any clear functional relation between frequency of sound and response ratio. Overall, 20–30% of larvae were consistently reacting to sound stimuli regardless of the frequency. In this study, we emphasize that larval behaviors when exposed to acoustic signals vary by individual, and thus a sufficient number of larvae should be surveyed at the same time under identical conditions, to better quantify their sensitivity to sound rather than repeating the experiment with individual specimens. Since bulk quantification, such as mean or quantile velocities of multiple specimens, can misrepresent larval behavior, our study finds that including the response ratio can more effectively reflect the larval response.

scholarly journals Oral Vaccination of Grass Carp (Ctenopharyngodon idella) with Baculovirus-Expressed Grass Carp Reovirus (GCRV) Proteins Induces Protective Immunity against GCRV Infection

Vaccines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 41
Author(s):  
Changyong Mu ◽  
Qiwang Zhong ◽  
Yan Meng ◽  
Yong Zhou ◽  
Nan Jiang ◽  
...  
Keyword(s):  
Survival Rate ◽  
Grass Carp ◽  
Oral Vaccine ◽  
Serum Antibody ◽  
Ctenopharyngodon Idella ◽  
Control Group ◽  
Oral Vaccination ◽  
Grass Carp Reovirus ◽  
Silkworm Pupae ◽  
Grass Carp Ctenopharyngodon Idella

The grass carp reovirus (GCRV) causes severe hemorrhagic disease with high mortality and leads to serious economic losses in the grass carp (Ctenopharyngodon idella) industry in China. Oral vaccine has been proven to be an effective method to provide protection against fish viruses. In this study, a recombinant baculovirus BmNPV-VP35-VP4 was generated to express VP35 and VP4 proteins from GCRV type Ⅱ via Bac-to-Bac baculovirus expression system. The expression of recombinant VP35-VP4 protein (rVP35-VP4) in Bombyx mori embryo cells (BmE) and silkworm pupae was confirmed by Western blotting and immunofluorescence assay (IFA) after infection with BmNPV-VP35-VP4. To vaccinate the grass carp by oral route, the silkworm pupae expressing the rVP35-VP4 proteins were converted into a powder after freeze-drying, added to artificial feed at 5% and fed to grass carp (18 ± 1.5 g) for six weeks, and the immune response and protective efficacy in grass carp after oral vaccination trial was thoroughly investigated. This included blood cell counting and classification, serum antibody titer detection, immune-related gene expression and the relative percent survival rate in immunized grass carp. The results of blood cell counts show that the number of white blood cells in the peripheral blood of immunized grass carp increased significantly from 14 to 28 days post-immunization (dpi). The differential leukocyte count of neutrophils and monocytes were significantly higher than those in the control group at 14 dpi. Additionally, the number of lymphocytes increased significantly and reached a peak at 28 dpi. The serum antibody levels were significantly increased at Day 14 and continued until 42 days post-vaccination. The mRNA expression levels of immune-related genes (IFN-1, TLR22, IL-1β, MHC I, Mx and IgM) were significantly upregulated in liver, spleen, kidney and hindgut after immunization. Four weeks post-immunization, fish were challenged with virulent GCRV by intraperitoneal injection. The results of this challenge study show that orally immunized group exhibited a survival rate of 60% and relative percent survival (RPS) of 56%, whereas the control group had a survival rate of 13% and RPS of 4%. Taken together, our results demonstrate that the silkworm pupae powder containing baculovirus-expressed VP35-VP4 proteins could induce both non-specific and specific immune responses and protect grass carp against GCRV infection, suggesting it could be used as an oral vaccine.

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