Target strength (TS) information is an important parameter that estimates the detection, distribution, and abundance of Aurelia aurita. In order to investigate the biological TS of jellyfish, some factors such as size (bell diameter), tilt angle, pulsation, and symbion should be known. In the ex situ TS measurements, the tilt angles and pulsation from synchronized swimming behavior of four live A. aurita (bell diameters in the air: 54.2 ~ 94.2 mm) were measured with the acoustic data at 70 kHz. The reduced target strength (RTS) of A. aurita was found to change ranged from 13.4 ~ 16.5 dB according to the incidence angles from –30° to 24°. When the change rate of bell diameter in the water was 0.2, the TS value showed a 7.2 dB change. These results could be utilized as an important data to understand the acoustic characteristic scattering of A. aurita.

• 윤은아 | Eun–A YOON
• 황두진 | Doo–Jin HWANG Corresponding author
• 広瀬美由紀 | HIROSE Miyuki
• 澤田浩一(전남대학교 해양기술학부) | Kouichi SAWADA (Division of Marine Technology, Chonnam National University, Yeosu 550–749, Korea)
• 福田美亮(전남대학교 해양기술학부) | Yoshiaki FUKUDA (Division of Marine Technology, Chonnam National University, Yeosu 550–749, Korea)
• 向井徹(전남대학교 해양기술학부) | Tohru MUKAI (Division of Marine Technology, Chonnam National University, Yeosu 550–749, Korea)