Seasonal and Spatial Patterns of Fish Sound Production in the May River, South Carolina

Many fish species produce sounds that are associated with reproductive behavior, and hydrophone recordings can be used to document this behavior in soniferous fishes. We recorded the sounds produced by a fish community and determined general seasonal and spatial patterns of fish sound production in the May River, South Carolina, as a means to assess general temporal and spatial patterns of reproduction. Two-minute sound files, temperature, salinity, and depth were recorded at 27 stations at monthly intervals along the May River in Bluffton, South Carolina, from January 2012 to December 2012. We identified species-specific calls from Spotted Seatrout Cynoscion nebulosus , Oyster Toadfish Opsanus tau , Silver Perch Bairdiella chrysoura , Black Drum Pogonias cromis , and Red Drum Sciaenops ocellatus . General species-specific seasonal patterns were noted; some species produced sounds within a specific time period and temperature range. Seasonally, Silver Perch, Oyster Toadfish, and Black Drum began calling in early spring and ended in May. Sound production of Spotted Seatrout began in early spring (i.e., February) and ended in early fall (i.e., end of September). The majority of Red Drum sound production occurred in August and September. Individual species had temperature-specific ranges in which they produced sound: Silver Perch, Oyster Toadfish, and Black Drum between 21°C and 26°C; Spotted Seatrout between 22°C and 30°C; and Red Drum between 28°C and 26°C. Species-specific spatial patterns of sound production were also observed. Fish calling rarely occurred near the source of the May River. Spotted Seatrout calls were predominately recorded at stations that displayed deep-hole characteristics with fallen trees. Red Drum preferred deeper habitat (i.e., water depths greater than 2.7 m) at the mouth of the May River. Seasonal and spatial patterns of courtship sounds suggest that each species has specific environmental criteria that are preferred for reproduction.