Functional plasticity of the swim bladder as an acoustic organ for communication in a vocal fish.

Teleost fishes have evolved a number of sound-producing mechanisms, including vibrations of the swim bladder. In addition to sound production, the swim bladder also aids in sound reception. While the production and reception of sound by the swim bladder has been described separately in fishes, the extent to which it operates for both in a single species is unknown.

Reproductive state modulates utricular auditory sensitivity in a vocal fish.

The plainfin midshipman, , is a seasonally breeding vocal fish that relies on acoustic communication to mediate nocturnal reproductive behaviors. Reproductive females use their auditory senses to detect and localize "singing" males that produce multiharmonic advertisement (mate) calls during the breeding season. Previous work showed that the midshipman saccule, which is considered the primary end organ used for hearing in midshipman and most other fishes, exhibits reproductive state and hormone-dependent changes that enhance saccular auditory sensitivity.

Response of toadfish () utricular afferents to multimodal inputs.

The inner ear of teleost fishes is composed of three paired multimodal otolithic end organs (saccule, utricle, and lagena), which encode auditory and vestibular inputs via the deflection of hair cells contained within the sensory epithelia of each organ. However, it remains unclear how the multimodal otolithic end organs of the teleost inner ear simultaneously integrate vestibular and auditory inputs. Therefore, microwire electrodes were chronically implanted using a 3-D printed micromanipulator into the utricular nerve of oyster toadfish () to determine how utricular afferents respond to conspecific mate vocalizations termed boatwhistles (180 Hz fundamental frequency) during movement.

Age-related loss of auditory sensitivity in the zebrafish (Danio rerio).

Age-related hearing loss (ARHL), also known as presbycusis, is a widespread and debilitating condition impacting many older adults. Conventionally, researchers utilize mammalian model systems or human cadaveric tissue to study ARHL pathology. Recently, the zebrafish has become an effective and tractable model system for a wide variety of genetic and environmental auditory insults, but little is known about the incidence or extent of ARHL in zebrafish and other non-mammalian models.

Anesthetic effects of AQUI-S 20E® (eugenol) on the afferent neural activity of the oyster toadfish (Opsanus tau).

Anesthesia is used to sedate aquatic animals during transportation or to immobilize them for surgery. However, most studies have focused on the behavioral effects of induction and recovery, without addressing the effect of anesthetic on neural activity. This study investigated the neural response of anterior lateral line afferent fibers in the oyster toadfish, Opsanus tau, during exposure to incremental increases of AQUI-S 20E (0.

Auditory evoked potentials of utricular hair cells in the plainfin midshipman, .

The plainfin midshipman, , is a soniferous marine teleost fish that generates acoustic signals for intraspecific social communication. Nocturnally active males and females rely on their auditory sense to detect and locate vocally active conspecifics during social behaviors. Previous work showed that the midshipman inner ear saccule and lagena are highly adapted to detect and encode socially relevant acoustic stimuli, but the auditory sensitivity and function of the midshipman utricle remain largely unknown.

The effect of biological and anthropogenic sound on the auditory sensitivity of oyster toadfish, Opsanus tau.

Many aquatic organisms use vocalizations for reproductive behavior; therefore, disruption of their soundscape could adversely affect their life history. Male oyster toadfish (Opsanus tau) establish nests in shallow waters during spring and attract female fish with boatwhistle vocalizations. Males exhibit high nest fidelity, making them susceptible to anthropogenic sound in coastal waters, which could mask their vocalizations and/or reduce auditory sensitivity levels.

Impacts of broadband sound on silver (Hypophthalmichthys molitrix) and bighead (H. nobilis) carp hearing thresholds determined using auditory evoked potential audiometry.

Invasive silver (Hypophthalmichthys molitrix) and bighead (H. nobilis) carp, collectively referred to as bigheaded carps, threaten aquatic ecosystems of the Upper Midwestern USA. Due to the extensive ecological impacts associated with these species, prevention of their further range expansion is the aim for fisheries management.

Reproductive state-dependent plasticity in the visual system of an African cichlid fish.

Visual communication is used widely across the animal kingdom to convey crucial information about an animals' identity, reproductive status, and sex. Although it is well-demonstrated that auditory and olfactory sensitivity can change with reproductive state, fewer studies have tested for plasticity in the visual system, a surprising detail since courtship and mate choice behaviors in many species are largely dependent on visual signals. Here, we tested for reproductive state-dependent plasticity in the eye of the cichlid fish Astatotilapia burtoni using behavioral, gene expression, neural activation, and electrophysiology techniques.

The effect of light stimuli on dark-adapted visual sensitivity in invasive silver carp Hypophthalmichthys molitrix and bighead carp H. nobilis.

Non-physical barriers, including the use of underwater strobe lights alone or paired with sound or bubbles, are being considered as a means to prevent the upstream migration of invasive silver carp Hypophthalmichthys molitrix and bighead carp H. nobilis. To optimize potential optical deterrents, it is necessary to understand the visual sensitivity of the fishes.

Lateral line sensitivity in free-swimming toadfish .

A longstanding question in aquatic animal sensory physiology is the impact of self-generated movement on lateral line sensitivity. One hypothesis is that efferent modulation of the sensory hair cells cancels self-generated noise and allows fish to sample their surroundings while swimming. In this study, microwire electrodes were chronically implanted into the anterior lateral line nerve of oyster toadfish and neural activity was monitored during forward movement.

An implantable two axis micromanipulator made with a 3D printer for recording neural activity in free-swimming fish.

Background: Chronically implanted electrodes allow monitoring neural activity from free moving animals. While a wide variety of implanted headstages, microdrives and electrodes exist for terrestrial animals, few have been developed for use with aquatic animals.

New Method: A two axis micromanipulator was fabricated with a Formlabs 3D printer for implanting electrodes into free-swimming oyster toadfish (Opsanus tau).