A.N. Popper and A. Hawkins (eds.), The Effects of Noise on Aquatic Life,
Advances in Experimental Medicine and Biology 730, DOI 10.1007/978-1-4419-7311-5_24,
© Springer Science+Business Media, LLC 2012
M. Bolgan ()
Facoltà di Scienze Matematiche, Fisiche e Naturali, Dipartimento di Scienze della Vita-CSEE ,
University of Trieste , 34127 Trieste , Italy
S. S. Pedroso • M. C. P. Amorim
Instituto Superior de Psicologia Aplicada , Unidade de Investigação em Eco-Etologia , 1149–041 Lisbon , Portugal
R. O. Vasconcelos • J. M. Jordão • P. J. Fonseca
Centro de Biologia Ambiental, Departamento de Biologia Animal ,
Faculdade de Ciências da Universidade de Lisboa , 1749–016 Lisbon , Portugal
Pomatoschistus pictus is a coastal and estuarine species that inhabits shallow gravel and sand
substrate areas of the eastern Atlantic Ocean and Mediterranean Sea (Miller 1986 ) . Studies on
P. pictus show that, like in other species of this genus (Malavasi et al. 2008 ) , males produce sounds
during courtship and agonistic contexts (Amorim and Neves 2007, 2008 ) .
The amount of anthropogenic noise pollution has been increasing significantly in the last decades
in coastal environments (Codarin et al. 2009 ; Ross 2005 ) . A noisy coastal environment may strongly
impact the ability of such a vocal species to communicate and, ultimately, reproduce. A first step in
understanding the impact of anthropogenic noise is to describe this species’ hearing sensitivity.
However, nothing has been described in terms of the auditory abilities of this genus to date. This
study presents the first data on the hearing sensitivity of P. pictus .
2 Materials and Methods
Six adult P. pictus were caught in April 2010 at Parede (38°41 ¢ N, 009°21 ¢ W), Portugal. The fish
were maintained in aquaria at 18 ± 1°C.
Hearing thresholds were estimated using the auditory evoked potential (AEP) recording technique.
Test subjects were mildly immobilized with 47.9 mg/g of pancuronium bromide diluted in teleost
saline solution. The subjects were placed just below the water surface of a plastic tank (diameter
36 cm, water depth 13 cm), 7 cm above the center of the underwater speaker disk. Fish respiration
was secured through a temperature-controlled (20 ± 1°C) gravity-fed seawater circulation system
Hearing Sensitivity of the Painted Goby,
Marta Bolgan, Silvia S. Pedroso, Raquel O. Vasconcelos,
Joana M. Jordão, M. Clara P. Amorim, and Paulo J. Fonseca
110 M. Bolgan et al.
using a micropipette tip inserted in the subject’s mouth. The experimental tank was positioned on a
vibration-insulated table surrounded by a Faraday cage.
The AEPs were recorded using platinum electrodes (diameter 1 mm). The recording electrode
was placed above the brain stem and the reference electrode was close to the nares. Electrode leads
were connected to a differential AC amplifier (CP 511, Grass Technologies). The AEP signal was
monitored with an oscilloscope and digitized using an analog-to-digital (A/D) converter (Edirol
UA25, Roland) connected to a personal computer running Adobe Audition 3.0 (Adobe Systems).
Sound stimuli were created with Adobe Audition 3.0 and consisted of tone pulses presented
1,000 times at opposite polarities. Hearing thresholds were estimated at 15 Hz with a repetition rate
of 5 s
-1 , 30 and 60 Hz with a repetition rate of 10 s
-1 , and 100, 200, 300, 400, 500, 800, and 1,000 Hz
with a repetition rate of 20 s
-1 , randomly presented. Sound stimuli ranged from 2 (15–100 Hz) to 5
complete cycles. Stimuli, presented in 4-dB steps from 92 to 136 dB re 1 mPa, were fed to a home-
made underwater speaker device and amplifier (P. J. Fonseca) using the laptop and an A/D converter
(Edirol UA 25). Before each experiment, the sound stimuli were calibrated with a hydrophone
(Brüel and Kjaer 8103) connected to a sound level meter (Brüel and Kjaer Mediator 2238) placed
in the same position as the fish. AEPs were averaged to minimize stimulus artifacts using home-
made software (P. J. Fonseca).
3 Preliminary Results
Some of the AEP waveforms obtained indicated a clear double-frequency effect, which was
further reassurance of a biological response. The audiogram showed that P. pictus sensitivity is
higher at low frequencies between 15 and 400 Hz, with the lowest hearing threshold of 105 dB re
1 mPa at 15 Hz (Fig. 1 ). This best hearing range matches the main sound energy of both courtship
(thump and drum) and agonistic (drum) calls, i.e., between ~83 and 297 Hz (Amorim and Neves
2007, 2008 ) .
Fig. 1 Hearing thresholds of Pomatoschistus pictus showing the range of the main sound energy of agonistic and
courtship calls. Values are averages ± SD
Hearing Sensitivity of the Painted Goby, Pomatoschistus pictus
The hearing sensitivity of P. pictus seems adapted to detect conspecific sounds, indicating that
acoustic communication provides essential information during species-specific interactions. In
addition, we suggest that the enhanced low-frequency sensitivity (below 60 Hz) could be the result
of an evolutionary adaptation that, for a benthonic species, maximizes the ability to detect prey,
predators, and mates.
Noise pollution is a threat to marine gobies (Codarin et al. 2009 ) . Noise energy of man-made
activity is mainly concentrated below 1 kHz (Nakahara 1999 ) . Because P. pictus acoustic commu-
nication occurs within this frequency range, the concern is that anthropogenic noise might be
strongly masking their hearing and hence their ability to communicate and to react to relevant
acoustic stimuli. Future work is needed to test the masking effect of noise pollution on hearing in
P. pictus .
Amorim MCP, Neves ASM (2007) Acoustic signaling during courtship in the painted goby, Pomatoschistus pictus .
J Mar Biol Assoc UK 87:1017–1023.
Amorim MCP, Neves ASM (2008) Male painted gobies ( Pomatoschistus pictus ) vocalize to defend territories.
Codarin A, Wysocki LE, Ladich F, Picciulin M (2009) Effect of ambient and boat noise on hearing and communica-
tion in three fish species living in a protected area (Miramare, Italy). Mar Pollut Bull 58:1880–1087.
Malavasi S, Collatuzzo S, Torricelli P (2008) Interspecific variation of acoustic signal in Mediterranean gobies
(Perciformes, Gobiidae): Comparative analysis an evolutionary outlook. Biol J Linn Soc 93:763–778.
Miller PJ (1986) Gobiidae. In: Whitehead PJP, Bauchot ML, Hureau JC, Nielsen J, Tortonese E (eds) Fishes of the
north-eastern Atlantic and the Mediterranean, vol. 3. UNESCO, Paris, pp 1019–1085.
Nakahara F (1999) Influences of the underwater man-made noise on acoustic behavior of dolphin. Otsuchi Mar Sci
Ross D (2005) Ship sources of ambient noise. IEEE J Ocean Eng 30:257–262.