FISH SOUNDS AND MATE CHOICE

Abstract

FISH ACOUSTIC SIGNALS ASSOCIATED WITH MATING BEHAVIOUR ARE TYPICALLY LOW-FREQUENCY SOUNDS PRODUCED BY MALES WHEN IN CLOSE PROXIMITY TO FEMALES. HOWEVER, SOME SPECIES MAKE SOUNDS THAT SERVE THE FUNCTION AND FOLLOW THE DESIGN OF ADVERTISEMENT CALLS, WELL KNOWN IN INSECTS, ANURANS, AND BIRDS. CLOSE-RANGE COURTSHIP ACOUSTIC SIGNALS MAY BE USED BY FEMALES IN MATE ASSESSMENT AS THEY CONTAIN INFORMATION OF MALE QUALITY SUCH AS SIZE AND CONDITION. FOR EXAMPLE, SOUND-DOMINANT FREQUENCY, AMPLITUDE, AND FATIGUE RESISTANCE MAY SIGNAL BODY SIZE WHEREAS PULSE PERIOD (I.E. MUSCLE CONTRACTION RATE) AND CALLING ACTIVITY ARE RELATED WITH BODY CONDITION IN SOME SPECIES. SOME SIGNAL FEATURES, SUCH AS SOUND PULSE NUMBER, MAY CARRY MULTIPLE MESSAGES INCLUDING SIZE AND CONDITION. PLAYBACK EXPERIMENTS ON MATE CHOICE OF A RESTRICTED NUMBER OF SPECIES SUGGEST THAT FEMALES PREFER VOCAL TO SILENT MALES AND MAY USE SOUND FREQUENCY, AMPLITUDE, AND MAINLY CALLING RATECALLING RATEWHEN ASSESSING MALES. THE ASSESSMENT OF MALES BY FEMALES BECOMES MORE CHALLENGING WHEN MALES ENGAGE IN CHORUSES OR WHEN SOUNDS ARE OTHERWISE MASKED BY ANTHROPOGENIC NOISE BUT ALMOST NOTHING IS KNOWN ABOUT HOW THESE ASPECTS AFFECT MATING DECISIONS AND FISH REPRODUCTIVE SUCCESS.