Humans have long been fascinated by the mysteries surrounding fish migrations and addressing these complex behaviors often requires large data sets. Biogeochemical tags, including trace elements and stable isotopes, are the most accessible biomarkers for tracking fish migrations. However, access to standardized biogeochemical tag data is rarely available for migratory fish, which limits our understanding of the evolutionary origins, drivers, timing, and corridors of migration. This precludes the development of conservation strategies and the implementation of management actions. Here, we present MFishBT, a global, open-access database of Migratory Fish\'s Biogeochemical Tags. As of April 2023, the MFishBT contains biogeochemical records from 1,305 studies, of which 53% used element-to-calcium (E/Ca) ratios, 34% used isotopic ratios, and 13% used both. The database covers 17,413 field sampling locations (inland 47% vs. marine 53%) around the globe, comprising 490 migratory fish species of four classes, 44 orders/suborders, and 137 families. In total, 77 trace elements and 11 isotope systems were measured across various fish biological archives, including otoliths, scales, eye lenses, and vertebrae. E/Ca ratios were examined more frequently than isotopic ratios, led by Sr/Ca, Mg/Ca, Ba/Ca, and 87 Sr/86 Sr, δ13 C, and δ18 O. The MFishBT compiles 27,030, 16,222, and 2,481,714 records with biogeochemical data detected in the core, edge, and core-to-edge transects for biological archives of migratory fish. This is the most globally comprehensive open-access database on biogeochemical tags in migratory fish to date, and can serve a variety of needs in scientific research, conservation, and management. We encourage researchers to add more data sets to this database in the future. This database is released for noncommercial use only. There are no copyright restrictions, and please cite this paper when using these data, or a subset of these data, for publication.

The complex life histories of demersal fishes are artificially separated into multiple stages along with changes in morphology and habitat. It is worth exploring whether the phenotypes expressed earlier and later during the life cycle are related or decoupled. The life stages of first year Pacific cod (Gadus macrocephalus) were tracked over different hatch years and regions to test whether the early life history had a long-lasting effect on subsequent growth. We further explored the contribution of growth in the early and subsequent life history stages to body size at the end of each stage. In addition to the accessory growth centre and the first annual ring, the other two checks on the otolith possibly related to settlement and entering deeper waters were identified in 75 Pacific cod individuals. The direct and indirect relationships among the life history stages was interpreted based on path analysis. The results showed that growth prior to the formation of the accessory growth centre had a significant effect on the absolute growth of the fish before and after settlement and migration to deep water. However, there was no or moderate evidence that early growth affected the body size at each stage, which was mainly regulated by growth during the stage. This study supports the lasting effect of early growth and clarifies that it affects size mainly by indirectly regulating staged growth. Quantifying the phenotype relationships and identifying the internal mechanisms form the basis for assessing population dynamics and understanding the processes behind the changes.
UNASSIGNED: The online version contains supplementary material available at 10.1007/s42995-022-00145-y.

The fluctuating asymmetry (FA) of fish otoliths can reflect the difference in the growth and development of fish in sea areas greatly affected by environmental pressure, thus enabling the assessment of different habitats. In this study, using 113 Collichthys lucidus samples collected from different functional areas (estuary area, aquaculture area, artificial reef area and natural area) in Haizhou Bay, the square coefficient of asymmetry variation (CV2 a ) of four characters (length, width, perimeter and area) of the left and right sagittal otoliths was calculated. The results showed that the CV2 a value of otolith width was the lowest and that of otolith length was the highest. The CV2 a value had no obvious regularity with increasing fish body length. In addition, the CV2 a values of the four characteristics reached their lowest values in the artificial reef area, indicating that the construction of marine ranching dominated by artificial reefs may partly improve the aquatic environment in this functional area. We consider that the otolith FA of C. lucidus can be used as a characteristic of environmental stress between different areas/regions/habitats.

The tapertail anchovy Coilia brachygnathus, a commercially important species mainly distributed along the mid-lower Chang-Jiang basin, is by far the most dominant species in Lake Honghu. To figure out its success in this semiclosed lake, some basic biological parameters of this anchovy were analysed based on samples seasonally collected from October 2020 to December 2021. The results demonstrated that the age classes of fished individuals varied from 0.5 to 3.5, with the majority (97.36%) being between 0.5 and 3 years old. The size at 50% maturity of 17.2 cm total length (TL) for females and 19.0 cm TL for males corresponded to 1 and 1.6 years, respectively. Coilia brachygnathus has a short life span, early sexual maturity and a relatively fast growth rate. The flourishing of the fish in the lake is mainly attributed to its short life span, early maturity, fast growth rate, closed fishing, pelagic spawners, the availability of plenty of food and low predation effect on it. Age 3.5 year occurs in an extremely small percentage of the total (<3%), indicating that a large number of larger-sized or older fish died after spawning, which is probably one of the major sources of water pollution if the closed fishing measure is adopted in Lake Honghu. Thus, individuals older than 2 years or more than 20.0 cm TL should be harvested. These findings have important management implications for the fish resources in Lake Honghu and beyond.
短颌鲚 (Coilia brachygnathus)是长江中下游的重要经济鱼类，是洪湖目前的优势物种。为弄清该种在此半封闭湖泊中繁盛的原因，本文基于2020 年 10 月至 2021 年 12 月季节性采集的样本，分析了该物种一些基本生物学参数。结果表明，采集样本的年龄为0.5-3.5龄，以0.5-3龄为主体(占总个体数97.36%)。50%个体性成熟时雌、雄性全长分别为 17.2 厘米和 19.0 厘米，对应的年龄分别是1龄和1.6龄。短颌鲚生命周期短，性成熟早，生长速度相对较快。该种种群在洪湖中繁盛的主要原因是:生命周期短、性成熟早、生长速度快、禁捕、产漂浮行卵、食物充足和捕捞压力小。3.5年龄个体占总量的比例极小(<3%)，说明大量体型较大或年龄较大的鱼类产卵后死亡。这可能是洪湖禁捕后水污染的主要来源之一。因此，应该捕捞年龄超过 2 年或全长超过20.0 cm的个体。这些发现对洪湖及其他地区的鱼类资源管理具有重要的意义。.

Eels have fascinated biologists for centuries due to their amazing long-distance migrations between freshwater habitats and very distant ocean spawning areas. The migratory life histories of the Japanese eel, Anguilla japonica, in the waters of south China are not very clear despite its ecological importance, and the need for fishery regulation and management. In this study, strontium (Sr) and calcium (Ca) microchemical profiles of the otoliths of silver eels were measured by X-ray electron probe microanalysis based on data collected from different habitats (including freshwater and brackish habitats), in the large subtropical Pearl River. The corresponding habitat preference characteristics were further analysed using redundancy analysis (RDA). A total of 195 Japanese eels were collected over 6 years. The collected individuals ranged from 180 to 771 mm in total length and from 8 to 612 g in body weight. Two-dimensional pictures of the Sr:Ca concentrations in otoliths revealed that the A. japonica in the Pearl River are almost entirely river eels, spending the majority of their lives in fresh water without exposure to salt water, while the catadromous migration time has delayed about 1 month in the Pearl River estuary in the past 20 years. RDA analysis further indicated that juveniles and adults preferred water with high salinity and high tide levels. Youth preferred habitats with high river fractals. Our findings contribute to a growing body of evidence showing that the eels are extremely scarce currently and conservation measures against them are imminent, including the protection of brackish and freshwater areas where they live in south China.
几个世纪以来，鳗鲡因其在淡水栖息地和海洋产卵区之间的长距离洄游而吸引了无数生物学家，但其在中国南方水系的洄游生活史并不十分清楚，尽管这具有重要的生态学意义。基于从大型亚热带河流--珠江水系不同生境 (包括淡水和半咸水)采集的鳗鲡数据，本研究采用X射线电子技术对银鳗耳石中锶 (Sr) 和钙 (Ca)的微化学特征进行了测定分析，同时采用冗余分析方法 (RDA)进一步分析了其相应的栖息地偏好。在6年的采样时间里，共采集日本鳗鲡 195 尾，全长介于 180-771 mm，体重介于 8-612 g。耳石中 Sr:Ca 浓度显示，珠江水系中的日本鳗鲡几乎全为河鳗，即一生中大部分时间都在淡水中度过。但是在过去的 20 年时间里，日本鳗鲡在珠江口的降海产卵时间推迟了约 1 个月。RDA分析进一步表明，幼鱼和成鱼偏向栖息于高盐度和高潮位的水体，而青年个体则更偏向栖息于河流分形较高的水体。我们的研究表明，珠江水系鳗鲡资源极为稀少，针对它们的保护措施，包括保护它们在中国南部的半咸水和淡水栖息地，迫在眉睫。.

Hairtail (Scombriformes: Trichiuridae) have always ranked first in single-species production in Chinese marine fishery. However, due to the confusion of species identification, in official statistics, data on hairtail production and economic value are a combination of all the different species of Trichiuridae. In this study, based on sampling along China\'s coastal areas, the composition and distribution of common hairtail species, as well as their age, growth, and trophic traits, are discussed. Six species of four genera and two subfamilies were identified, and largehead hairtail (Trichiurus japonicus) and Savalai hairtail (Lepturacanthus savala) were the most important populations that constituted catch production. The growth parameter b could be divided into two groups, with values in species mostly inhabiting northern parts of Chinese seas higher than those in southern parts. Most individuals were 1-2 years of age, suggesting species sexual precocity and individual miniaturization under multiple stresses. Species of Trichiuridae are at the top of the food web and play a bottom-up role in regulating the trophic dynamics of marine food webs. Largehead hairtail showed the highest stability and the greatest impact on the stability of the trophic structure. Despite temporary resource maintenance under fishery-induced evolution, the effective recovery and reasonable utilization of hairtail resources are still the main focuses of attention for Chinese marine fishery.

In recent years, the frequent occurrence of most human activities has seriously affected the structure and functioning of coastal ecosystems. The asymmetric relationship between the left and right otoliths of fish is often used to test the difference in fluctuating asymmetry (FA) reflected by the square of the coefficient of asymmetric variation (CV2 a ), which can be regarded as an important step in the study of marine environmental pressure and implementation of offshore ecological restoration. In this study, the authors tested the bilateral FA of Collichthys lucidus in the coastal waters of Haizhou Bay, Jiangsu, and Xiangshan Bay, Zhejiang, China, using four sagittal otolith characters (length, width, perimeter and area) as biological characters. The results showed that the value of CV2 a in otolith width (more sensitive to environmental pressure) of C. lucidus in Xiangshan Bay was higher than that in Haizhou Bay, indicating that the environmental pressure on Xiangshan Bay was relatively high. The authors did not find any significant differences in the FA of otoliths between different body sizes of C. lucidus, which may be related to the short-distance migration in different regions and the dietary shifts in the life history of this species. The results have conservation and management implications for this population.

Objective:To investigate the effect of different rotations modes of control rod on testing results of the subjective visual vertical （SVV）. Methods:Twenty-four normal young volunteers were selected for this study, and the control rod of SVV was rotated in clockwise, counterclockwise and any direction at the head tilt-positions of 0°, 45° left and 45° right. The differences of SVV deflection angle values at different rotation modes were analyzed. Results:①The deviation angle values of SVV obtained by rotating the control rod in clockwise, counterclockwise and any direction at the head tilt-positions of 0° were 1.56°±0.21°, 3.05°±0.24°, and 2.16°±0.22°, respectively，and the difference was statistically significant （P<0.05）,the deviation angle value of SVV in clockwise direction was smaller; ②At head tilt-positions of 45° left, the SVV deviation angle values obtained by rotating the control rod in three rotation modes were 2.59°±0.53°, 4.03°±0.51°, and 3.49°±0.54°, respectively, and the difference was statistically significant（P<0.05）,the deviation angle value in the clockwise direction was also smaller; ③At the head tilt-positions of 45° right, the SVV deviation angle values in three modes were 4.68°±0.58°, 7.23°±0.72°, and 5.93°±0.96°, respectively, and the difference was statistically significant （P<0.05）,the deviation value of SVV was also smaller when rotated in the clockwise direction; ④Comparison of SVV deviation angle values in three rotation modes at the head tilt-positions of 45° left and 45° right showed that there was no statistical difference in clockwise and in any direction （P>0.05）, while the difference was statistically significant when rotated in the counterclockwise direction （P<0.05）. Conclusion:Different rotation modes of the control rod during SVV testing will affect the test results. Rotating the control rod in clockwise direction to make the SVV values more accurate is recommended.
目的：探讨控制棒的不同旋转方式对主观视觉垂直线（SVV）检测结果的影响。 方法：选取24例健康青年人，在正中（0°）、左侧45°、右侧45°三种不同头位下分别对SVV检测仪控制棒进行任意方向、顺时针和逆时针方向旋转，分析不同旋转方式下上述三种头位的SVV偏斜度的差异。 结果：①正中（0°）头位下，顺时针、逆时针和任意方向旋转控制棒所得SVV偏斜度分别为1.56°±0.21°、3.05°±0.24°和2.16°±0.22°，差异有统计学意义（P<0.05），顺时针方向旋转控制棒所得SVV偏斜度更小；②左侧45°头位下，顺时针、逆时针和任意方向旋转控制棒所得SVV偏斜度分别为2.59°±0.53°、4.03°±0.51°和3.49°±0.54°，差异有统计学意义（P<0.05），顺时针方向旋转控制棒所得SVV偏斜度更小；③右侧45°头位下，顺时针、逆时针和任意方向所得SVV偏斜度分别为4.68°±0.58°、7.23°±0.72°和5.93°±0.96°，差异有统计学意义（P<0.05），顺时针方向旋转所得SVV偏斜度更小；④左侧45°与右侧45°头位下不同旋转方式SVV偏斜度比较显示，顺时针和任意方向旋转控制棒所得SVV偏斜度的差异无统计学意义（P>0.05），而逆时针旋转控制棒所得SVV偏斜度差异有统计学意义（P<0.05）。 结论：SVV测试时控制棒的不同旋转方式会对测试结果产生影响，为了使获得的SVV偏斜度数值更准确，推荐采用顺时针方向旋转控制棒进行SVV检测操作。.

Otoliths are biological crystals formed by a layer of calcium carbonate crystal that adhere to the ciliary surface of the utricular and saccular receptors in the vestibule of all vertebrates inner ear, enabling the utricle and saccule to better perceive the changes in linear and gravitational acceleration. However, the molecular etiology of otolith related diseases is still unclear. In this review, we have summarized the recent findings and provided an overview of the proteins that play important roles in otolith formation and maintenance (Otoconin-90, Otolin-1, Otolith Matrix Protein-1, Cochlin, Otogelin, α-Tectorin, β-Tectorin, Otopetrin-1, and Otopetrin-2, PMCA2, etc.), providing new insight for the prevention and management of benign paroxysmal positional vertigo (BPPV) with basis for otolith-related proteins as potential biomarkers of vestibular disease.

The objective of this research was to investigate the mechanism of canal switching in benign paroxysmal positional vertigo through a virtual simulation model. Using Unity 3D software and a built-in NVIDIA Physx physics engine, the virtual simulation software is developed using a browser-server architecture, and different models are imported. Based on the benign paroxysmal positional vertigo virtual simulation model, we constructed five different virtual reality scenes of diagnosis and treatment, set otoliths in different positions of the semicircular canals, and analyzed the effects of diagnostic and therapeutic procedures on otolith location. Through the analysis of otolith movement in five virtual scenes, we found that canal switching may be caused by otoliths in the utricle entering the semicircular canal in the supine position. Then, we used different methods to reposition the otolith, improved the repositioning maneuver, and explored in depth the mechanism of the canal switching. The results showed that the main reason for the canal switch is that in the supine position, the otolith in the utricle enters the semicircular canal. The repositioning maneuvers, including the Epley maneuver and Barbecue maneuver, will not directly lead to the canal switch in the ipsilateral inner ear. The supine roll maneuver leads to the otolith in the utricle entering the posterior or lateral semicircular canal, which is the most likely mechanism for canal switching.