Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Hybrid redear

Abstract
Sounds were recorded in colonies of six species of sunfish (Lepomis megalotis, L. humilis, L. punctatus, L. macrochirus, L. cyanellus and L. microlophus) under natural conditions. No sounds were heard in a seventh species (L. auritus) during observations that included 17 courtships and three spawnings. This lack of sound production during courtship may be an important cue for mate recognition in this species. The calls of the sound-producing species consist of a series of grunt-like sounds or popping sounds (in L. microlophus) and were heard during active courtship of a female by a nesting male. The males produced at least part of the sounds because L. megalotis, L. humilis, and L. macrochirus males could be induced to court and call to dead females that were manipulated on a string. Also, the jaws of L. microlophus males could be seen to snap shut as the popping sounds were heard during courtship. The sound producing mechanism in the other species and whether or not the females also produce sounds is not known. Except for the L. microlophus sounds, which may exhibit transients with frequencies up to about 7 KHz, the frequencies used in these calls is under 2 KHz, with the highest amplitudes under 1 KHz. The mean sound duration for each species is about 0.64 seconds except for L. cyanellus which averages 0.36 seconds. The mean pulse repetition rates of L. punctatus, L. megalotis, and L. humilis are different at the 0.01 level. The sounds of L. macrochirus, L. cyanellus, and L. microlophus showed almost no pulsation. L. cyanellus has a much shorter grunt duration than L. macrochirus and L. microlophus and these two differ primarily in the number of sounds per call. L. microlophus produces one or at most two sounds together while L. macrochirus almost always produces a series of grunts. The total number of sounds recorded for each species and the percentage showing pulsation are: L. macrochirus 80 (7%), L. punctatus 200 (25%), L. humilis 199 (66%), L. megalotis 141 (96%), L. cyanellus 24 (0%), and L. microlophus 34 (0%). Preliminary playback experiments of the courtship sounds indicate that L. megalotis, L. humilis and possibly L. macrochirus are attracted to their conspecific calls, at least during spawning. The other species have not been tested yet.