scholarly journals Target strength measurements on tethered live jellyfish Nemopilema nomurai

2005 ◽  
Vol 71 (4) ◽  
pp. 571-577 ◽  
Author(s):  
MIYUKI HIROSE ◽  
TOHRU MUKAI ◽  
DOOJIN HWANG ◽  
KOHJI IIDA
2006 ◽  
Vol 120 (5) ◽  
pp. 3106-3106
Author(s):  
Miyuki Hirose ◽  
Tohru Mukai ◽  
Kohji Iida ◽  
Doojin Hwang

2009 ◽  
Vol 66 (6) ◽  
pp. 1233-1237 ◽  
Author(s):  
Miyuki Hirose ◽  
Tohru Mukai ◽  
Doojin Hwang ◽  
Kohji Iida

Abstract Hirose, M., Mukai, T., Hwang, D., and Iida, K. 2009. The acoustic characteristics of three jellyfish species: Nemopilema nomurai, Cyanea nozakii, and Aurelia aurita. – ICES Journal of Marine Science, 66: 1233–1237. Reports about jellyfish damaging nets and reducing fish catches are increasing, and data on the abundance and distribution of various jellyfish species are needed to forecast where and when their blooms will happen. Acoustic techniques can be used to obtain this information if the acoustic characteristics of the targets are known. This is a study of acoustic scattering from three jellyfish species: Nemopilema nomurai (order Rhizostomeae), Cyanea nozakii (Semaeostomeae), and Aurelia aurita (Semaeostomeae). Target strength (TS) at 38, 120, and 200 kHz, specific density, and sound speed were measured with live specimens. Specific densities were measured using the displacement–volume–weight and the dual-density methods. The sound speeds were estimated using the time-of-flight method. The reduced TS (RTS), i.e. the TS normalized by bell area, was smaller for N. nomurai (bell diameter range 19–38 cm) than for C. nozakii (bell diameter range 30–40 cm), and the differences in RTS between the species were 17.8, 12.6, and 5.8 dB at 38, 120, and 200 kHz, respectively. The respective sound-speed contrast h and density contrast g were 1.0008 ± 0.009 (mean ± s.d.) and 1.004 ± 0.015 for N. nomurai; 1.038 and 1.073 for one C. nozakii; and 1.0001 ± 0.025 and 0.989 ± 0.019 for A. aurita.


2013 ◽  
Vol 71 (3) ◽  
pp. 597-603 ◽  
Author(s):  
Donhyug Kang ◽  
Jusam Park ◽  
Seom-Kyu Jung ◽  
Sungho Cho

Abstract Acoustic target strength (TS) measurements were made of ex situ giant jellyfish Nemopilema nomurai Kishinouye at 38 and 120 kHz. These TS data may be useful for developing acoustic scattering models, and surveying giant jellyfish distributions and biomasses. Each jellyfish was tethered in seawater using a monofilament line that vertically penetrated its bell's centre. During the acoustic measurements, an underwater video camera was used to continuously monitor the jellyfish's behaviour. Acoustic measurements were made using split-beam transducers. TS measurements were made of 27 individual jellyfish, but data were analysed for 23 specimens (bell diameter in air, Dair = 21–65 cm) at 38 kHz, and 19 specimens (Dair = 21–46 cm) at 120 kHz, respectively. Least-squares regression fits of TS vs. log(Dair) were TS38kHz = 20•log10Dair–82.7 (r = 0.76) and TS120kHz = 20•log10Dair–86.7 (r = 0.79). The mean TS values at 38 and 120 kHz, using the average Dair = 40.3 cm and 35.5 cm, respectively, were −50.6 and −55.7 dB. The reduced TS, a function of the ratio of Dair to wavelength (λ), was RTS(Dair/λ) = −6.1•log10(Dair/λ) –36.1 (r = 0.51). These RTS values decreased with increasing Dair/λ. Symbiotic medusa shrimp (Latreutes anoplonyx Kemp) contributed negligible bias to our TS measurements of giant jellyfish. These ex situ TS measurements may be used in acoustic surveys to estimate the distributions and biomasses of N. nomurai.


2000 ◽  
Vol 25 (4) ◽  
pp. 346-353 ◽  
Author(s):  
Alex P. Norman ◽  
Gareth Jones
Keyword(s):  

2009 ◽  
Vol 1 (1) ◽  
Author(s):  
Henry M. Manik

A preliminary research programme was carried out in order to study the acoustic wave reflection or target strength (TS) of tuna fish using a quantitative echo sounder (QES). The relationships between TS to fork length (FL) and swimbladder volume, for bigeye tuna (Thunnus obesus) and yellowfin tuna (T. albacares) are investigated. The TS of bigeye tuna was about 3 dB higher than yellowfin tuna when comparing species at the same size. The result can be correlated to the swimbladder volume differencebetween species. The relationship between TS and swimbladder volume was quantified for both species.Keywords: tuna fish, target strength, quantitative echo sounder


Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 311
Author(s):  
Indu Choudhary ◽  
Duhyeon Hwang ◽  
Jinho Chae ◽  
Wonduk Yoon ◽  
Changkeun Kang ◽  
...  

Jellyfish venom is well known for its local skin toxicities and various lethal accidents. The main symptoms of local jellyfish envenomation include skin lesions, burning, prickling, stinging pain, red, brown, or purplish tracks on the skin, itching, and swelling, leading to dermonecrosis and scar formation. However, the molecular mechanism behind the action of jellyfish venom on human skin cells is rarely understood. In the present study, we have treated the human HaCaT keratinocyte with Nemopilema nomurai jellyfish venom (NnV) to study detailed mechanisms of actions behind the skin symptoms after jellyfish envenomation. Using two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF/MS), cellular changes at proteome level were examined. The treatment of NnV resulted in the decrease of HaCaT cell viability in a concentration-dependent manner. Using NnV (at IC50), the proteome level alterations were determined at 12 h and 24 h after the venom treatment. Briefly, 70 protein spots with significant quantitative changes were picked from the gels for MALDI-TOF/MS. In total, 44 differentially abundant proteins were successfully identified, among which 19 proteins were increased, whereas 25 proteins were decreased in the abundance levels comparing with their respective control spots. DAPs involved in cell survival and development (e.g., Plasminogen, Vinculin, EMILIN-1, Basonuclin2, Focal adhesion kinase 1, FAM83B, Peroxisome proliferator-activated receptor-gamma co-activator 1-alpha) decreased their expression, whereas stress or immune response-related proteins (e.g., Toll-like receptor 4, Aminopeptidase N, MKL/Myocardin-like protein 1, hypoxia up-regulated protein 1, Heat shock protein 105 kDa, Ephrin type-A receptor 1, with some protease (or peptidase) enzymes) were up-regulated. In conclusion, the present findings may exhibit some possible key players during skin damage and suggest therapeutic strategies for preventing jellyfish envenomation.


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