Little is known about how changes in the biodiversity and functional traits of macroinvertebrates in rivers respond to the responses of anthropic pressures and their driving factors. Macroinvertebrates were sampled at 17 sites in the Irtysh River Basin and classified macroinvertebrates into 10 traits and 38 categories between May and August 2022. Then, we performed R-mode linked to Q-mode (RLQ) analysis and calculated functional richness, evenness, divergence, and Rao’s quadratic entropy (RaoQ) for each site and community-weighted means for each trait category. Our results indicated that there were pronounced alterations in species variability in the urban region. Functional divergence indicated fierce competition among species and considerable niche overlap in the urban region. Functional evenness indicated that species abundance distribution and interspecific functional distance were not uniform in the urban region. Functional richness indicated that the urban region was the strongest region in terms of niche occupation, resource utilization, and buffering capacity for environmental fluctuations. Rao’s quadratic entropy showed that the trait difference of macroinvertebrates was the largest in all regions, which was caused by the gradient environmental difference. Research has revealed that urbanization significantly influences the evolutionary trajectory of macroinvertebrate fauna, culminating in an upsurge in pollution-tolerant species and a convergence of functional traits. We recommend strengthening the control of urban and industrial pollution and wise planning and management of land and water resources to mitigate the impact of anthropogenic destruction on habitat fragmentation in the Irtysh River Basin.

To study the morphological differences between and the evolutionary mechanisms driving the differentiation of geographically distinct populations of Gymnodiptychus dybowskii, 158 fish were collected from the Turks River and the Manas River in Xinjiang from 2020 to 2021 with the approval of the Academic Ethics Committee. The morphological characteristics of the fish were assessed using classical fish ecology methods such as traditional morphometric measurements and the framework approach. The results showed that the morphological characteristics of the populations in the Turks River and Manas River were significantly different; a one-way ANOVA revealed 22 highly significant differences (p < 0.01) and 1 significant difference (p < 0.05) among the 33 morphological traits of the observed populations, and a principal component analysis revealed that there was no overlap between the two populations of G. dybowskii. The main characteristics associated with principle component 1 were the terminus of the dorsal fin to the ventral origin of the caudal fin (D—F), the dorsal origin of the caudal fin to the origin of the anal fin (E—H), and the insertion of the pectoral fin to the terminus of the pectoral fin (J—K); the main factors associated with principal component 2 were the body height (BD), the terminus of the dorsal fin to the insertion of the pelvic fin (D—I), the caudal peduncle height (CPH), and the tip of the snout to the last end of the frontal maxilla (A—B); and the main traits associated with principle component 3 were the terminus of the anal fin to the origin of the anal fin (G—H), the body width (BW), the insertion of the pelvic fin to the terminus of the pelvic (I—L), the insertion of the pectoral fin to the terminus of the pectoral fin (J—K), and the insertion of the pelvic fin to the insertion of the pectoral fin (I—J). An OPLS-DA revealed that the two populations could be wholly separated and that the intergroup growth traits of the Manas River population were different and significantly greater than those of the Turks River population. The discriminant functions of the Turks River and Manas River populations of G. dybowskii were as follows: Y_T = −432.033 + 1787.748X₁ + 826.517X₂ + 249.002X₃ + 1183.050X₄ + 554.934X₅ + 999.296X₆ + 627.428X₇; Y_M = −569.819 + 2041.044X₁ + 344.942X₂ + 333.737X₃ + 940.512X₄ + 348.222X₅ + 1167.770X₆ + 1015.904X₇. According to a coefficient of variation analysis, a total of nine traits, namely, EI/BL, C-D/BL, E-F/BL, F-H/BL, H-I/BL, C-J/BL, D-I/BL, D-H/BL, and D-F/BL, had a CD > 1.28, indicating that the differences in these nine traits had reached the subspecies level. The results showed that G. dybowskii significantly differed between the two geographically distinct populations in the Turks River and the Manas River and have differentiated to the subspecies level. This study provides a basis for a better investigation of the population structure of highland endemic fishes and the mechanisms by which they diverged and lays a foundation for developing and utilizing germplasm resources from endemic fishes in Xinjiang.

Schizothoracinae species are the largest group of Cypriniformes that readily adapt to the natural conditions of the Qinghai-Tibet Plateau. This group has habitat characteristics and distribution patterns centered on the Qinghai-Tibet Plateau. To study the evolution of three Schizothoracinae species in Northwest China, the evolutionary characteristics of these species were explored based on differences in otolith morphology and skeletal morphology. From 2020 to 2022, 138 samples (63 Aspiorhynchus laticeps, 35 Diptychus maculatus and 40 Schizothorax pseudaksaiensis) were collected from the Tarim River and Ili River, 6 basic morphological parameters of otoliths were measured and converted into 6 morphological factors and 7 morphological indices. A total of 77 Fourier transform coefficients of each otolith were selected The first three principal components accounted for 92.834% of the total variation in 13 otolith morphological indices of the three Schizothoracinae species, and the overall discrimination rate was 94.20%. According to the principal component analysis of 77 Fourier harmonic values of otoliths, the first 20 principal components explained 97.233% of the total variation, and the overall discrimination rate was 100%. The results of the cluster analysis directly reflected the relationships between related species. The differences in the bone morphology of the three Schizothoracinae species were particularly reflected in the number of whiskers, pharyngeal teeth and vertebrae, and there were also significant differences in the shapes of the sphenotic (SP), pterotic (PTE), preoperculum (PO), branchiostegal ray (BRA) and basibranchial (BB) bones. Their unique morphological and skeletal characteristics are closely related to geological changes and water system evolutionary trends. This study contributes to the understanding of species identification and the evolutionary status of plateau fishes, provides a reference for further evolutionary classification and for assessing the evolutionary mechanisms of plateau fishes, and provides a scientific basis for phylogeny and germplasm resource protection.

In order to deeply analyze the individual biological characteristics of unique fish in China, lay a solid foundation for the effective protection of its germplasm resources, and further enrich and consolidate the basic biological data system of endemic fish in the world. According to the ethical norms and fishing licenses, 5 samples of Diptychus maculatus and 3 samples of Aspiorhynchus laticeps were collected from the Tarim River system in Baicheng County from 2023 to 2024. The morphological characteristics, age identification and anatomical observation of the two fishes were analyzed by classical biological methods. Both fish belong to Cypriniformes, Cyprinidae, Schizothoracinae. D. maculatus has a long body, a conical head, and a lower mouth with a pair of fish whiskers. The mouth is slightly blunt and arcuate, and the lateral line is complete. A. laticeps has a long, slightly flattened body, a round abdomen, and a large head that is flattened at the front. It also has a pair of fish whiskers located at the corners of the mouth. Age identification materials: D. maculatus lapillus 6+, asteriscus 6+, vertebra 6+, anal scales 6+, opercular bone 5+, A. laticeps lapillus 7+, asteriscus 7+, vertebra 7+, anal scales 7+, opercular bone 7+. The peritoneal wall of D. maculatus is black or brown the tooth type was 3·4-4·3; the external behavior of gill rakers was 8-13; and the internal behavior was 12-16. A. laticeps pharynx teeth 3 lines, tooth type is 2·3·5-5·3·2; the external behavior of gill rakers was 11-13; and the internal behavior was 15-18. D. maculatus and A. laticeps are special species distributed in the Tarim River system. Their evolutionary adaptation is closely related to the uplift of the Qinghai-Tibet Plateau. This study provides important data for better understanding the individual biological characteristics of these two endangered fish species and lays the foundation for their germplasm resource conservation.

EDNA metabarcoding has been used for the biomonitoring of benthic invertebrates, but the correct steps to achieve its effectiveness, the stability of the results, and comparisons with morphological methods are still understudied. In this study, morphology and eDNA were studied for benthic invertebrate samples collected at six sites in the Ulungu River Basin. A Mantel test and NMDS analyses were used to test the correlations of the communities obtained via the two methods, the Shannon index was calculated to evaluate the ecological status, and the correlation of the evaluation results was analyzed. The results revealed that eDNA metabarcoding did not detect a greater number of species than the morphological method, that the results from the two methods shared fewer taxa at the family level and below, and that only five taxa were shared at the genus level. The Mantel test and NMDS analyses revealed very significant differences between the communities monitored by the two methods (PERMANOVA, p = 0.0056), but eDNA metabarcoding provided richness and abundance data for species that are difficult to identify morphologically, and these findings can be used to supplement the morphological data. The cor.test revealed that there was no significant correlation between the diversity and ecological assessment results of the two methods, and the ecological assessment results of eDNA metabarcoding cannot represent accurate and true ecological conditions. The water sample eDNA-based method and morphological method exhibited low consistency and high complementarity in monitoring benthic invertebrate communities and diversity. More research is still needed on the key links of eDNA sampling, the control of the degradation rate, data utilization, and index development to provide more environmentally friendly and effective monitoring methods for ecological protection, more reliable support for ecological decision-making, and to more adequately respond to the challenges of global environmental change.

The age, growth, and reproduction of Schizothorax pseudaksaiensis (Herzenstein, 1889), a second-level key protected aquatic species in Xinjiang, were studied using fish ecology methods, and the biological characteristics of its population are discussed. A total of 735 specimens were collected on a seasonal basis from 2021 to 2022 using cages and nets in the Turks River. The fish length ranged from 47.30 mm to 538.60 mm, and the minimum age and maximum age were 1 years old and 23 years old, respectively. The fitting correlations revealed that S. pseudaksaiensis is a uniformly growing fish. The ages at the inflection point for S. pseudaksaiensis were 22.28 (female) and 19.55 (male). The sex ratio was 0.89 (females):1 (males), and the spawning period occurred from April to July. The absolute fecundity was 55,652.01 ± 25,468.78 eggs per individual, and the relative fecundity was 25.92 ± 10.69 eggs per gram. This study provides life history trait data for S. pseudaksaiensis and has theoretical and practical importance for maintaining population dynamics and fishery ecological balance. Additionally, a basis for the protection of fishery germplasm plateau resources is provided.