Some, says Burgess, employ muscles “attached to the walls of their balloonlike swim bladders to vibrate those walls until their bladders ” resonate like drums.
Burgessi sõnul kasutavad mõningad neist „õhupallitaolise ujupõie seintele kinnituvaid lihaseid, mis panevad need seinad vibreerima, nõnda et ujupõis hakkab trummi kombel resoneerima.