How do ostariophysan fishes produce sounds?

Ostariophysan fishes produce sounds primarily through mechanisms associated with the swim bladder. The specific methods vary by species:1

• Expulsion of air: Minnows generate noise by expelling air through the pneumatic duct and the mouth, while loaches expel air through the anus.1
• Vibratory mechanisms: In many catfish families, muscles attached to a springlike mechanism (derived from modified vertebrae) pull against the swim bladder. This causes the bladder wall to vibrate rapidly, creating humming or growling sounds.1
• Stridulation: Some catfishes produce sound through the grating or rubbing movements of their pectoral and dorsal spines.1

While the Weberian apparatus is a defining feature of the series Otophysi, it is primarily involved in enhancing hearing rather than sound production. By linking the swim bladder to the inner ear, this bony chain allows these fishes to detect a wide range of frequencies with high sensitivity.123