Daniel E. Holt

The relationship between ambient noise and dominant frequency of vocalizations in two species of darters (Percidae: Etheostoma )

Acoustic communication is used by many freshwater fishes for both courtship and aggressive interactions. Fish that live in shallow streams with fast moving water are often exposed to high levels of ambient noise, which could have an effect on the characteristics of their vocalizations. This paper investigates the aggressive vocalizations produced by two closely related species of darters. We measured ambient noise in their respective microhabitats, and found that both species produce aggressive drum vocalizations with a dominant frequency that corresponds to areas of low ambient noise. Previous studies have found quiet windows in shallow streams that have correlated to the dominant frequency of sounds made by fish that inhabit the streams. This is the first study, however, to show how the dominant frequencies of vocalizations of two closely related species occur in areas of low ambient noise within their respective microhabitats. This study supports other studies which show that ambient noise along with other physical features of the environment can affect vocal characteristics and behaviors in freshwater fish.

Hearing sensitivity in two black bass species using the auditory brainstem response approach

Recently, several bioacoustic studies have focused on the red eye bass (Micropterus coosae). One of these studies documented sound production, while the other played back sounds produced by prey items in order to determine their attractiveness to M. coosae. Surprisingly, the hearing ability of fishes in the genus Micropterus has received very little attention. The need for audiograms describing hearing in Micropterus is apparent. This study utilized the auditory brainstem response (ABR) approach to determine hearing sensitivity in terms of both sound pressure level (SPL) and particle acceleration in two black bass species, the red eye bass (M. coosae) and the Alabama bass (M. henshalli). Audiograms produced in this study expressed in both SPL and particle acceleration showed a positive relationship between hearing threshold and frequency. Micropterus coosae was most sensitive to frequencies that overlap with the peak frequencies of their vocalizations, and the vocalizations of a prey species, Cyprinella trichroistia. Bass hearing sensitivities at lower frequencies, measured in terms of particle acceleration, were similar to several sciaenid species.

Can you hear the dinner bell? Response of cyprinid fishes to environmental acoustic cues

Fishes in the superorder Ostariophysi have excellent hearing due to the presence of a synapomorphic hearing specialization called the Weberian apparatus. This structure connects the swim bladder to the inner ear, and increases both sensitivity and upper hearing range. Although numerous experiments have tested the effects of the Weberian apparatus on hearing, few have provided potential evidence for a current adaptive function for the specialization. We conducted a field-based experiment in which a rock shuffling noise and a white noise were played simultaneously from adjacent speakers in a clear, mountain stream in the southern Appalachian Mountains, U.S.A. Our results indicate that species of Cyprinidae, a family within Ostariophysi, were attracted more to rock shuffling noise than to the white noise. This study provides the first evidence that a broadband environmental sound associated with a potential food source is utilized by a potentially large number of species possessing a hearing specialization.

Sound production and associated behaviours in blacktail shiner Cyprinella venusta: a comparison between field and lab

Acoustic signals and associated behaviours of a number of fishes in the genus Cyprinella have been investigated and described in detail, but due to logistics, these studies have been done in the laboratory. We used C. venusta as a model for evaluating potential differences in acoustic signals in field versus laboratory settings. In addition to this analysis, a detailed description of acoustic signals and associated behaviours was produced. We found that males were the only sex to vocalize and did so during reproductively associated behaviours such as courtship, aggression, and spawning. Sounds were similar in gross structure to most other species of Cyprinella in that they were composed of bursts and knocks, but differed in a number of signal parameters including acoustic frequency, pulse duration, pulse period, and pulse rate. One of the more striking findings was that the acoustic frequency distributions of both growls and knocks in C. venusta were bi-modal, a characteristic not mentioned for any other species in the genus Cyprinella. Sounds recorded in the laboratory were also found to be significantly different from those recorded in the field.

Signaling without the risk of illegitimate receivers: do predators respond to the acoustic signals of Cyprinella (Cyprinidae)?

Acoustic and visual signals are commonly used by fishes for communication. A significant drawback to both types of signals is that both sounds and visual stimuli are easily detected by illegitimate receivers, such as predators. Although predator attraction to visual stimuli has been well-studied in other animals, predator response to acoustic stimuli has received virtually no research attention among fishes and snakes. This study assessed whether the calls of male tricolor shiner (Cyprinella trichroistia) made during the breeding season would attract potential predators. We also examined the effect of visual stimulus of tricolor shiners on predators. Predators used were red eye bass (Micropterus coosae) and midland water snakes (Nerodia sipedon pleuralis). Neither predator was attracted to tricolor sounds when presented alone. Micropterus coosae responded significantly more to a visual stimulus, and to a combination of visual and acoustic stimuli, but with no greater intensity in the latter. Nerodia sipedon pleuralis did not responded to visual stimulus presented alone, but did respond to visual and acoustic stimuli presented simultaneously, and with greater intensity to the latter, indicating that acoustic signals may play a role in prey detection by N. sipedon pleuralis.

Stress and Auditory Responses of the Otophysan Fish, Cyprinella venusta, to Road Traffic Noise.

Noise pollution from anthropogenic sources is an increasingly problematic challenge faced by many taxa, including fishes. Recent studies demonstrate that road traffic noise propagates effectively from bridge crossings into surrounding freshwater ecosystems; yet, its effect on the stress response and auditory function of freshwater stream fishes is unexamined. The blacktail shiner (Cyprinella venusta) was used as a model to investigate the degree to which traffic noise impacts stress and hearing in exposed fishes. Fish were exposed to an underwater recording of traffic noise played at approximately 140 dB re 1 μPa. Waterborne cortisol samples were collected and quantified using enzyme immunoassay (EIA). Auditory thresholds were assessed in control and traffic exposed groups by measuring auditory evoked potentials (AEPs). After acute exposure to traffic noise, fish exhibited a significant elevation in cortisol levels. Individuals exposed to 2 hours of traffic noise playback had elevated hearing thresholds at 300 and 400 Hz, corresponding to the most sensitive bandwidth for this species.

Convergent Aspects of Acoustic Communication in Darters, Sculpins, and Gobies

Darters (Perciformes, Percidae), sculpins (Perciformes, Cottidae), and gobioids (Gobiiformes, Gobioidei) exhibit convergent life history traits, including a benthic lifestyle and a cavity nesting spawning mode. Soniferous species within these taxa produce pulsed and/or tonal sounds with peak frequencies below 200 Hz (with some exceptions), primarily in agonistic and/or reproductive contexts. The reduced or absent swim bladders found in these taxa limit or prevent both hearing enhancement via pressure sensitivity and acoustic amplification of the contracting sonic muscles, which are associated with the skull and pectoral girdle. While such anatomies constrain communication to low frequency channels, optimization of the S/N (signal-to-noise) ratio in low frequency channels is evident for some gobies, as measured by habitat soundscape frequency windows, nest cavity sound amplification, and audiograms. Similar S/N considerations are applicable to many darter and sculpin systems. This chapter reviews the currently documented diversity of sound production in darters, sculpins, and gobioids within a phylogenetic context, examines the efficacy of signal transmission from senders to receivers (sound production mechanisms, audiograms, and masking challenges), and evaluates the potential functional significance of sound attributes in relation to territorial and reproductive behaviours.

Role of environmental acoustic cues in the evolution of hearing specialization in cyprinidae.

Numerous studies have documented hearing specializations in fishes, but virtually no work has focused on the adaptive significance of sensitive hearing to fishes. An exception is the finding that marine clupeid fishes have an adaptation for hearing the ultrasonic acoustic signals of their mammalian predators, an obvious advantage. The idea that hearing specializations in most fishes evolved as a predator detection mechanism has not been tested in freshwater fishes, however, and due to ecosystem differences may not explain the evolution of such traits. Field observations suggested that cyprinids (Ostariophysi) congregate near areas of disturbed substrate to feed on dislodged aquatic insects and debris. This led to the exploration of whether the acoustic cues associated with substrate disturbance alone would attract cyprinds via a field playback experiment. These results may shed light on the detection of feeding cues as one of the potential selective pressures associated with the evolution of sensitive hea...

The effect of noise on behavior and acoustic communication in the blacktail shiner (Cyprinella venusta).

Despite their seemingly quiet underwater habitat, freshwater fishes are not sheltered from elevated noise levels. Anthropogenic noise along with natural noise sources increase noise levels in aquatic environments. Higher noise levels can result in elevated hearing thresholds and decrease the signal‐to‐noise ratio of acoustic signals. Because many fishes use acoustic signals during critical life history stages, it is important to determine whether elevated noise levels affect behavior or sound production during these stages. This study describes sound production and corresponding behaviors as well as hearing in the black tail shiner (Cyprinella venusta). An attempt was also made to determine the effect of elevated noise levels on acoustic communication and behaviors associated with reproduction and aggression. Behavioral interactions of C. venusta were recorded under noisy and quiet acoustic conditions. Temporal and spectral parameters of the calls as well as the type and number of behaviors performed by t...