Target strength measurements of pointhead flounder, Cleisthenes pinetorum, a flatfish without a bladder

There are only a few acoustic surveys of the bladderless fish. As is known by all, Atlantic mackerel was surveyed these years by echo-sounder and showed the high target strength at high frequency. In northern Japan, an interesting fish attracted the attention these years which called pointhead flounder, Cleisthenes pinetorum, without a bladder. It is a flatfish but captures prey in the middle water column. And the body shape is not the normal...