Sounds were produced by the males of two species of cichlid fishes while courting females.
Each courtship sound consisted of a series of distinct pulses occurring in rapid succession.
Courtship sounds produced by Tramitichromis cf. intermedius and
Copadichromis conophorus were significantly different in pulse rate and individual
pulse durations. For C. conophorus calls (n = 3.27) the mean ± sd number of
pulses per call was 10 ± 3 and call duration was 181 ± 59 ms. There was a
significant positive linear relationship between call duration and the number of pulses
(r2 = 0.912, p < 0.001). The dominant frequency of the pulses in calls
was 471 ± 50 (range 372-594) Hz (n = 40 calls). T. cf. intermedius
also produced a pulsed courtship call; data (mean ± sd) from two male T. cf.
intermedius: 9 ± 2 pulses per call and duration 199 ± 44 ms
(n = 20 calls). The linear regression between call duration and number or pulses was
positive (r2 = 0.463, p = 0.001). Pulse rate within calls of T. cf.
intermedius compared to C. conophorus were significantly different
(p = 0.018). Individual pulse durations were also significantly different (p = 0.043)
between species. However, interpulse intervals were not significantly different (p = 0.177).
These cichlids produced courtship sounds that were distinct by individual pulse durations
and by pulse repetition rate in a call.