Fish ear bones, known as otoliths, are often collected in fisheries to assist in management, and are a common sample type in museum and national archives. Beyond their utility for ageing, morphological and trace element analysis, otoliths are a repository of valuable genomic information. Previous work has shown that DNA can be extracted from the trace quantities of tissue remaining on the surface of otoliths, despite the fact that they are often stored dry at room temperature. However, much of this work has used reduced representation sequencing methods in clean lab conditions, to achieve adequate yields of DNA, libraries and ultimately single-nucleotide polymorphisms (SNPs). Here, we pioneer the use of small-scale (spike-in) sequencing to screen contemporary otolith samples prepared in regular molecular biology (in contrast to clean) laboratories for contamination and quality levels, submitting for whole-genome resequencing only samples above a defined endogenous DNA threshold. Despite the typically low quality and quantity of DNA extracted from otoliths, we are able to produce whole-genome libraries and ultimately sets of filtered, unlinked and even putatively adaptive SNPs of ample numbers for downstream uses in population, climate and conservation genomics. By comparing with a set of tissue samples from the same species, we are able to highlight the quality and efficacy of otolith samples from DNA extraction and library preparation, to bioinformatic preprocessing and SNP calling. We provide detailed schematics, protocols and scripts of our approach, such that it can be adopted widely by the community, improving the use of otoliths as a source of valuable genomic data.

Climate warming is causing shifts in reproductive phenology, a crucial life history trait determining offspring survival and population productivity. Evaluating these impacts on exploited marine resources is essential for implementing adaptive measures from an ecosystemic approach. This study introduces a statistical model designed to predict fish spawning phenology from sea surface temperature profiles, integrating mortality-corrected hatch-date distributions inferred from fishery-dependent samplings, along with the gonadosomatic index of adult individuals. When applied to different dolphinfish (Coryphaena hippurus) populations across a broad latitudinal range, the model reasonably predicts the spawning phenology across its extensive thermal ranges, elucidating a direct relationship between mean annual temperature and the breadth of the spawning season. Despite the varying thermal profiles, results show a consistent timing of spawning peaks approximately 49 days before the peak in temperature. Importantly, these findings account for the impact of fishery constraints, such as seasonal closures or different sampling schedules, offering a robust tool for adjusting management practices in response to inter-annual temperature variations. These insights are critical for both short-term fishery management, including the strategic planning of seasonal closures, and long-term projections of spawning phenology shifts under changing thermal regimes. By enhancing our ability to predict spawning times, this research contributes significantly to the sustainable management of fish populations and the adaptive response to environmental changes.

UNASSIGNED: Sound stimulation can influence electrophysiological vestibular reflexes. However, the effects of sound stimulation on space perception remain unknown.
UNASSIGNED: To know the effects of monaural sound stimulation on subjective visual vertical (SVV).
UNASSIGNED: We measured SVV with and without monaural sound stimulation (105 dB, 500 Hz short tone burst presented at 4.7 Hz) in 50 healthy volunteers (aged 20-77 [mean = 42.7] years).
UNASSIGNED: The mean SVV was deviated 0.139° to the left by right monaural sound stimulation and 0.123° to the right by left monaural sound stimulation. SVV changes due to right and left ear stimulations were significantly different (p = 0.019). Sound stimulation resulted in a significant change in SVV on the left side (p = 0.014) in participants aged 50 or younger (mean = 35.6 years) (n = 37).
UNASSIGNED: This study is the first to show the possibility that the monaural sound input deviates the SVV toward the opposite side and is more pronounced for left-ear input. The vestibular-evoked myogenic potential responses may be involved in the mechanism of the contralateral SVV deviation due to sound input.

The case of the deepwater redfish (Sebastes mentella) in the Gulf of St. Lawrence (GSL) is a compelling example of drastic fluctuations in annual recruitment strength, characteristic of spasmodic stocks. After three decades of low abundance, the emergence of three consecutive strong year classes in 2011-2013 resulted in an unprecedented increase in biomass. In spasmodic stocks such as GSL redfish, strong year classes sustain both the biomass and catch for decades. Therefore, understanding the growth dynamics of these cohorts is essential. In the present study, we reconstructed the annual growth rates of redfish using otolith increment-based annual chronology and investigated the drivers of growth variation in redfish strong year classes of the early 2010s and early 1980s. Stock biomass was identified as the main extrinsic driver of redfish growth, suggesting intense competition for food at high conspecific density. Warming of deep waters in the GSL, where adult redfish settle, positively correlated with individual growth. However, recent warming of the cold intermediate layer showed a negative correlation with redfish growth, likely related to the shrinking of the habitat this water mass provides for various redfish cold-water prey rather than to a direct effect of temperature. Reconstruction of redfish annual growth trajectories from birth to capture emphasized the importance of carryover effects in the growth potential of strong year classes. This work provided an important first outlook of the factors driving growth variation in GSL redfish spasmodic stock and explored midterm consequences of density-dependent pressures on biological parameters of the population.

The inner ear is responsible for balance and auditory function. Sensorineural hearing loss (SNHL) affects auditory function across various age groups. Vestibular apparatus, particularly the otolith organ can also be affected in cases of SNHL because of the close proximity of the otolith organs with the cochlea inside the bony labyrinth. The otolith organs can be assessed with Subjective Visual vertical test (SVV), which is a simple, rapid, non-invasive test with high sensitivity and specificity. Present study was conducted with the objective to compare the SVV parameters between normal and SNHL patients and to correlate between the degree of tilt in SVV with severity of SNHL. A convenient sample size of 60 was taken of which 30 were control and 30 were SNHL patients. PTA and SVV were performed on both groups and results were analysed in IBM SPSS version 26. Age stratified analysis between the control group and SNHL group for the age group 20-40 years and for > 40 years revealed a significant statistical difference in the average static SVV (P = 0.019 and P = 0.009 for age group 20-40 years and > 40 years respectively) and dynamic anti clockwise SVV (P = 0.024 and P = 0.031 for age group 20-40 years, and > 40 years respectively) between the control group and the SNHL group. Correlational analysis also shows a moderate correlation between the bone conduction threshold and the various SVV parameters. Statistical difference of SVV parameters between the two groups suggests a possible early involvement of the otolith organ in SNHL. As such the utility of SVV as an early marker for otolith dysfunction needs to be further explored. It may be worthwhile to follow up the patients of SNHL longitudinally and assess the otolith function with SVV at periodic intervals to identify any progression.

Increasing carbon dioxide levels associated with climate change will likely have a devastating effect on aquatic ecosystems. Aquatic environments sequester carbon dioxide, resulting in acidic conditions that can negatively affect fish development. Increasing climate change impacts in the coming decades will have an outsized effect on younger generations. Therefore, our research had two interconnected goals: 1) understand how aquatic acidification affects the development of zebrafish, and 2) support a high school scientist\'s ability to address environmental questions of increasing importance to her generation. Working with teachers and other mentors, the first author designed and conducted the research, first in her high school, then in a university research laboratory. Zebrafish embryos were reared in varying pH conditions (6.7-8.2) for up to 7 days. We assessed fish length and development of the inner ear, including the otoliths; structures that depend on calcium carbonate for proper development. Although pH did not affect fish length, fish reared in pH 7.75 had smaller anterior otoliths, showing that pH can impact zebrafish ear development. Furthermore, we demonstrate how zebrafish may be used for high school students to pursue open-ended questions using different levels of available resources.

BACKGROUND: Perceptible galvanic vestibular stimulation (GVS) causes nystagmus and postural sway deterioration. Conversely, imperceptible GVS improves postural stability, suggesting the presence of stochastic resonance.
OBJECTIVE: Similar to GVS, strong magnetic vestibular stimulation of 7 T induces nystagmus and increases body sway. Thus, a relatively small magnetic stimulation may improve postural stability. In this study, we measured the effect of a relatively small magnetic field on postural sway.
METHODS: Posturography was performed in eight healthy participants using a stabilometer with foam rubber on board. The center of pressure (COP) trajectories were recorded in both the anterior-posterior and medial-lateral directions for 60 s with the eye closed. Neodymium magnets (0.4 T) or aluminum disks of similar size (0 T) were placed bilaterally over the mastoid processes.
RESULTS: Both the trajectory length and envelopment area of the COP movement with 0.4 T were significantly smaller than those with 0 T.
CONCLUSIONS: The relatively smaller magnetic vestibular stimulation decreased postural sway. This method may be useful for improving the vestibular function and related reflexes.

Trace elements and stable isotope ratios in otoliths have been used as proxies for the migration history of teleosts; however, their application in oceanic fishes remains limited. This study reports the first use of radiocarbons in otoliths to evaluate the horizontal migration histories of an oceanic fish species, the walleye pollock Gadus chalcogrammus. We conducted radiocarbon analyses of three stocks sourced from Hokkaido, Japan. The radiocarbon concentrations from the outermost portion of the otoliths from the Japanese Pacific, Northern Japan Sea (JS), and Southern Okhotsk Sea (OS) stocks were in general agreement with the seawater radiocarbon concentration of the sampling region, suggesting that pollock of all three stocks generally inhabited the within the sea region where each pollocks were sampled throughout their life cycle. However, the radiocarbon signals also provided some indications that some JS and OS stocks may be migrating between different sea regions. The proposed novel approach of reconstructing the individual migration history of marine fish using radiocarbon in otoliths may help examine fish migration with a higher temporal and spatial resolution that could not be achieved by trace elements and stable isotope ratios.

UNASSIGNED: Although various medical remedies have been attempted to alleviate the symptoms of Meniere\'s disease (MD), the risk-benefit ratios of these various treatments remain debatable.
UNASSIGNED: We investigated the efficacy of sound stimulation of 100 Hz for treating vestibular dysfunction in patients with Meniere\'s disease (MD).
UNASSIGNED: Patients with definitive MD with intractable vestibular symptoms and endolymphatic hydrops (EH) in the inner ear were evaluated. The experimental group received sound stimulation of 75 dB at a frequency of 100 Hz for 5 min, and the control group received sound stimulation of 75 dB at a frequency of 250 Hz for 5 min. Cervical vestibular-evoked myogenic potentials (cVEMPs) were measured before and after each sound stimulation, and the results of the clinical tests were compared between the two patient groups.
UNASSIGNED: Significant increases in cVEMP amplitudes were observed after sound stimulation of 100 Hz in ears with vestibular endolymphatic hydrops, although no such improvement was observed in the control group.
UNASSIGNED: Sound stimulation of 75 dB at a frequency of 100 Hz leads to improvement in cVEMP amplitude in patients with definitive MD. Adequate sound stimulation might be a new method for treating vestibular dysfunction associated with MD.

Fluctuating ocean conditions are rearranging whole networks of marine communities-from individual-level physiological thresholds to ecosystem function. Physiological studies support predictions from individual-level responses (biochemical, cellular, tissue, respiratory potential) based on laboratory experiments. The otolith-isotope method of recovering field metabolic rate has recently filled a gap for the bony fishes, linking otolith stable isotope composition to in situ oxygen consumption and experienced temperature estimates. Here, we review the otolith-isotope method focusing on the biochemical and physiological processes that yield estimates of field metabolic rate. We identify a multidisciplinary pathway in the application of this method, providing concrete research goals (field, modeling) aimed at linking individual-level physiological data to higher levels of biological organization. We hope that this review will provide researchers with a transdisciplinary \'roadmap\', guiding the use of the otolith-isotope method to bridge the gap between individual-level physiology, observational field studies, and modeling efforts, while ensuring that in situ data is central in marine policy-making aimed at mitigating climatic and anthropogenic threats.