The process by which spermatogonial stem cells (SSCs) continuously go through mitosis, meiosis, and differentiation to produce gametes that transmit genetic information is known as spermatogenesis. Recapitulation of spermatogenesis in vitro is hindered by the challenge of collecting spermatogonial stem cells under long-term in vitro culture conditions. Coilia nasus is a commercially valuable anadromous migrant fish found in the Yangtze River in China. In the past few decades, exploitation and a deteriorating ecological environment have nearly caused the extinction of C. nasus’s natural resources. In the present study, we established a stable spermatogonial stem cell line (CnSSC) from the gonadal tissue of the endangered species C. nasus. The cell line continued to proliferate and maintain stable cell morphology, a normal diploid karyotype, and gene expression patterns after more than one year of cell culture (>80 passages). Additionally, CnSSC cells could successfully differentiate into sperm cells through a coculture system. Therefore, the establishment of endangered species spermatogonial stem cell lines is a model for studying spermatogenesis in vitro and a feasible way to preserve germplasm resources.

The decline of Japanese eel (Anguilla japonica) populations in the Yangtze River estuary represents a critical conservation concern. Eleven-years of daily catch data during recruitment periods (i.e., January–April, 2012–2022) indicate that annual catch averaged from 153 to 1108 eels, and show a bimodal pattern in glass eel arrivals. Utilizing seasonal-trend decomposition and generalized additive models, we demonstrated a strong correlation between catch abundance, optimal water temperatures, and lunar cycles. An auto-regressive integrated moving average (ARIMA) model predicts an increase in glass eel numbers for 2023–2024 but also points to a concerning trend of delayed recruitment timing since 2016, attributable to the 0.48 °C per decade rise in sea surface temperatures. This delay correlates with a significant decrease in the average body weight of glass eels, suggesting potential energy deficits that may hinder successful upstream migration. This study not only furthers our understanding of glass eel recruitment dynamics but also underscores the urgent need for targeted conservation measures. Additionally, it highlights the importance of sustained, detailed monitoring to mitigate the detrimental effects of climate change on these eels, vital for preserving the Yangtze River’s ecological integrity.

The comprehensive 10‐year fishing moratorium implemented in the Yangtze River Basin since 2021 provides a unique opportunity to evaluate the recovery of threatened fish populations. This study assessed the recovery status of Coilia nasus in the lower reaches of the Yangtze River during the fourth year of the moratorium through analysis of age structure, growth parameters, and sex ratio. Field investigations were conducted at two strategic locations (Chongming and Taizhou) during the migration season (May–June 2024), yielding 3077 specimens. Results revealed significant improvements in population parameters, including increased mean age (2.64 years) and standard length (28.5 cm), alongside a higher proportion of age 3 and age 4 individuals (63.3%). Sex ratio analysis showed a pronounced female bias (3.19:1), with spatial variations between estuarine (4.99:1) and upstream (2.04:1) sites. Growth parameter analysis indicated a shift toward natural growth dynamics, with increased asymptotic length ( L _∞ ) and altered growth rates ( k ) compared to premoratorium periods. Despite these positive indicators, the absence of five‐year‐old individuals and lower average length compared to historical records suggest incomplete recovery. Our findings provide evidence for the effectiveness of the fishing ban while highlighting the need for continued protection.

To evaluate the ecological effects of 10-year fishing ban policy in the Yangtze River on the population recovery of Coilia nasus, this study systematically analyzed the temporal dynamics of growth characteristics using multi-model inference approaches based on information criteria. A total of 958 specimens were collected during fishing seasons in 2005, 2009, 2012, and 2024 from the Taizhou section of the Yangtze River. The results showed: (1) Population structure optimized significantly, with age composition shifting from younger to older cohorts. The proportion of 3—4 year-old individuals increased notably from 24.7% in 2009 to 72.4% in 2024, while the sex ratio (female:male) recovered from 0.69:1 to 2.66:1. (2) Morphometric parameters exhibited a typical U-shaped recovery pattern, with mean body length increasing from the historical low of 24.2 cm in 2009 to 29.6 cm in 2024, and mean body weight increasing from 58.4 to 105.0 g, representing increases of 22.3% and 79.8%, respectively. (3) The von Bertalanffy growth model showed the best fit, revealing significant sexual dimorphism in growth parameters: females exhibited greater asymptotic length than males, with L_∞ values of 39.05 cm for females and 32.63 cm for males, but lower growth coefficient, with k values of 0.41 for females and 0.56 for males, reflecting a “slow growth-large body size” life history strategy, while males adopted a “fast growth-small body size” strategy. Temporal analysis revealed U-shaped and inverted U-shaped recovery trajectories for L_∞ and k, respectively. (4) Population recovery exhibited sex-specific differences, with females fully recovering to 2005 levels and showing enhancement, while males improved but with relatively delayed recovery. This study confirms the significant positive effects of 10-year fishing ban policy in the Yangtze River on C. nasus population conservation and resource recovery, providing important empirical support for assessing the effectiveness of aquatic biodiversity conservation in the Yangtze River Basin and scientific basis for formulating adaptive management strategies for endangered anadromous fish species.

Seasonal hydrology reshapes large-river food webs by altering habitat connectivity and basal resource availability. Trophic baselines from before the 2021 Yangtze ten-year fishing ban are now valuable because monitoring has shifted from fish abundance alone toward food-web function and ecological recovery. We analysed carbon (δ¹³C) and nitrogen (δ¹⁵N) stable isotopes of fish and the baseline bivalve Corbicula fluminea collected in March (dry season) and August (wet season) 2016 from the Jingjiang section of the lower Yangtze River. In the dry season, 100 individuals of 27 species were analysed; species mean δ¹³C ranged from −30.52‰ (Micropercops swinhonis) to −21.19‰ (Aristichthys nobilis) and δ¹⁵N from 6.30‰ (Hypophthalmichthys molitrix) to 14.90‰ (Lophiogobius ocellicauda). In the wet season, 187 individuals of 47 species were analysed; species mean δ¹³C ranged from −32.07‰ (Pseudobrama simoni) to −20.84‰ (Salanx ariakensis) and δ¹⁵N from 6.27‰ (Misgurnus anguillicaudatus) to 14.87‰ (Saurogobio gymnocheilus). Among 24 shared species, δ¹³C differed significantly between seasons (paired t = 4.30, p < 0.001), but δ¹⁵N did not (t = 1.52, p = 0.143). Mean trophic level fell from 3.07 to 2.74 (t = 3.85, p < 0.001). This decline remained significant in a trophic-enrichment-factor sensitivity analysis using 2.5–4.0‰. Community-wide carbon range (CR), nitrogen range (NR), total convex-hull area (TA), mean nearest-neighbour distance (NND), and the standard deviation of nearest-neighbour distance (SDNND) showed larger wet-season CR (9.08 vs. 7.51), slightly larger NR, TA and NND, and lower SDNND. Seasonal hydrology thus mainly altered basal carbon pathways and relative trophic positions rather than reorganising feeding guilds. The dataset provides a pre-ban isotopic baseline for assessing whether post-ban recovery in the lower Yangtze includes restoration of trophic structure and energy-flow pathways.