African cichlid Pseudotropheus spp. males moan to females during foreplay

This study describes a new courtship sound (moan) produced by Pseudotropheus spp. males, not previously reported for cichlids. Moans are short tonal sounds often showing frequency modulation. This sound type is of very low amplitude and is produced when males swim in close proximity to a female, usually before performing more exuberant behavioural exhibitions, such as darting, quivering the body and growling.