drum muscle

one of the muscles attached to the gas bladder which makes the contained gas vibrate and emit a drumming sound. In pimelodid catfishes, for example, a muscle originates on the parapophyses of the 4 vertebra and sometimes too from the neurocranium and inserts on the ventro- and ventro-lateral surfaces of the gas bladder. Fish with drumming muscles also have a tensor tripodis, q.v., to reduce sound conduction to the inner ear See also drum, elastic spring mechanism and protractor post-temporalis mechanism