Below is the information on why some spotted seatrout make sounds while others do not. The answer is that male spotted seatrout have a specialized muscle called a sonic muscle that vibrates against the swim bladder, producing drumming or croaking sounds.

This muscle is exclusive to male spotted seatrout and is used to attract females during spawning, as illustrated in the picture. Furthermore, research has shown that their red sonic muscle is prominent only during spawning and becomes inactive during winter. This is also observed in male red drum, spot, star drum, and silver perch, although both sexes of black drum and Atlantic croaker possess sonic muscles.

Picture 1: Male spotted seatrout anatomy

Picture 2: Female spotted seatrout anatomy