Full Description

"Recordings with a hydrophone deployed from a boat and the shore revealed that the sciaenid Whitemouth Croaker Micropogonias furnieri produces a seasonal and daily characteristic courtship/spawning sound in the Pando stream mouth on the Rio de la Plata estuary during the spawning season from November to March. Recordings were made at five stations. The drumming sound was qualitatively rated on scale of 0-4, according to criteria proposed by Connaughton & Taylor (1995). Recordings of 5 marked individuals were made in a 3000-1 canvas tank in the laboratory for three months (December 2006 — March 2007). The drumming or advertisement call of Whitemouth Croaker was strongly seasonal, appearing in October, increasing to a peak in January — March, and then disappearing abruptly in April, in coincidence with the spawning season and with gonadosomatic index (GSI). Daily drumming activity showed two peaks through the day, increasing in the early morning between 07-00 to 10:00 h and in the evening between 17:00 to 23:00 h."

"The Whitemouth Croaker produces two different sounds: an advertisement call (drumming sound) during the spawning season, produced only by males; and a disturbance call produced by both sexes. In Whitemouth Croaker, both male and female possess well developed sonic muscles (Tellechea et al. 2008)."

"The data were analyzed qualitatively by scoring the number or intensity of drumming in a minute, following Connaughton & Taylor (1995). The scored categories were: 0 = no sound production, 1 = very few drumming sounds (< 30 pulses min™), 2 = some drumming (30-50 pulses min“), 3 = continuous sound production of drumming (>50 pulses min-!), 4 = continuous sound production (Figure 2). After each recording session we used a beach net (40 mm mesh in the wings and 10 mm at the cod ends; vertical opening 1 m; and 200 m length) (Saona et al. 2003) to estimate the number of individuals in the vicinity of the recording site: scarce individuals (n<10); very few individuals (n=10-15); few individuals (n=30-40); many individuals (n=90-150 or more). In this way we could relate the categories of sound scores with the number of individuals. Drumming sounds were characterized by frequencies from 160 to 400 Hz (Tellechea et al. 2008). With the records collected during the study period, drumming activity by month, by time of day and by sampling date were analyzed and considered indicative of spawning activity."

"Average daily calling activity of Whitemouth Croaker drumming sounds declined substantially following a substantial change in water temperature, strong wind or storm and motorized boat activity, but was unrelated to tidal current speed or direction."

Observation Environment Quotes

"Recordings with a hydrophone deployed from a boat and the shore revealed that the sciaenid Whitemouth Croaker Micropogonias furnieri produces a seasonal and daily characteristic courtship/spawning sound in the Pando stream mouth on the Rio de la Plata estuary during the spawning season from November to March. Recordings were made at five stations. The drumming sound was qualitatively rated on scale of 0-4, according to criteria proposed by Connaughton & Taylor (1995). Recordings of 5 marked individuals were made in a 3000-1 canvas tank in the laboratory for three months (December 2006 — March 2007). The drumming or advertisement call of Whitemouth Croaker was strongly seasonal, appearing in October, increasing to a peak in January — March, and then disappearing abruptly in April, in coincidence with the spawning season and with gonadosomatic index (GSI). Daily drumming activity showed two peaks through the day, increasing in the early morning between 07-00 to 10:00 h and in the evening between 17:00 to 23:00 h."

Behaviour Description Quotes

"Recordings with a hydrophone deployed from a boat and the shore revealed that the sciaenid Whitemouth Croaker Micropogonias furnieri produces a seasonal and daily characteristic courtship/spawning sound in the Pando stream mouth on the Rio de la Plata estuary during the spawning season from November to March. Recordings were made at five stations. The drumming sound was qualitatively rated on scale of 0-4, according to criteria proposed by Connaughton & Taylor (1995). Recordings of 5 marked individuals were made in a 3000-1 canvas tank in the laboratory for three months (December 2006 — March 2007). The drumming or advertisement call of Whitemouth Croaker was strongly seasonal, appearing in October, increasing to a peak in January — March, and then disappearing abruptly in April, in coincidence with the spawning season and with gonadosomatic index (GSI). Daily drumming activity showed two peaks through the day, increasing in the early morning between 07-00 to 10:00 h and in the evening between 17:00 to 23:00 h."

"The Whitemouth Croaker produces two different sounds: an advertisement call (drumming sound) during the spawning season, produced only by males; and a disturbance call produced by both sexes. In Whitemouth Croaker, both male and female possess well developed sonic muscles (Tellechea et al. 2008)."

Sound Name Quotes

"Recordings with a hydrophone deployed from a boat and the shore revealed that the sciaenid Whitemouth Croaker Micropogonias furnieri produces a seasonal and daily characteristic courtship/spawning sound in the Pando stream mouth on the Rio de la Plata estuary during the spawning season from November to March. Recordings were made at five stations. The drumming sound was qualitatively rated on scale of 0-4, according to criteria proposed by Connaughton & Taylor (1995). Recordings of 5 marked individuals were made in a 3000-1 canvas tank in the laboratory for three months (December 2006 — March 2007). The drumming or advertisement call of Whitemouth Croaker was strongly seasonal, appearing in October, increasing to a peak in January — March, and then disappearing abruptly in April, in coincidence with the spawning season and with gonadosomatic index (GSI). Daily drumming activity showed two peaks through the day, increasing in the early morning between 07-00 to 10:00 h and in the evening between 17:00 to 23:00 h."

" The data were analyzed qualitatively by scoring the number or intensity of drumming in a minute, following Connaughton & Taylor (1995). The scored categories were: 0 = no sound production, 1 = very few drumming sounds (< 30 pulses min™), 2 = some drumming (30-50 pulses min“), 3 = continuous sound production of drumming (>50 pulses min-!), 4 = continuous sound production (Figure 2)."