Natural Reproduction Research Articles

Challenges and Strategies in the Industrial Application of Dendrobium officinale.

Dendrobium officinale Kimura & Migo (D. officinale) is a well-recognized traditional Chinese medicinal herb that is both medicinal and edible. Contemporary pharmacological studies have revealed that D. officinale contains abundant bioactive compounds, including polysaccharides, flavonoids, alkaloids, and dendrobine, exhibiting diverse pharmacological properties such as antioxidant, anti-inflammatory, and immunomodulatory effects. However, the industrial application of D. officinale faces many problems, such as the scarcity of wild resources, low natural reproduction rate, and slow growth rate as well as the lack of relevant industrial standards. Nevertheless, substantial advancements, including the exploitation of artificial propagation techniques and breeding of new varieties, have been achieved in recent years. These developments have effectively addressed the challenges associated with its low natural reproduction rate and the scarcity of wild resources. This review summarizes the progress in the industrial development, seedling cultivation, and pharmacological exploration of D. officinale in recent years. Furthermore, it analyzes current research inadequacies and offers strategic solutions to enhance its application in healthcare and medicine.

Imagination, Reality, and Reproduction: Comparing Perceptions of Coastal Sea Trout Anglers, Real Catches, and Sea Trout Spawning Activity

ABSTRACTSustainable management of recreational fisheries requires balancing angler attitudes and behaviour with fisheries' biological potential. Herein, we investigated the balance in the sea‐run brown trout (Salmo trutta) fishery around the Swedish island of Gotland using data collected through a creel survey, test fishing, and spawning returns to selected streams. Anglers accurately anticipated catches of large fish but underestimated the role of natural reproduction in supporting the stock. Female sea trout entering spawning streams and post‐spawn sea trout caught on the coast were significantly larger than spawning males and non‐spawned fish, and were particularly important for the fishery. Larger sea trout also faced a higher level of harvest pressure than other sizes. Small changes to angler preferences, harvest rates, or regulations could significantly influence characteristics and sustainability of this fishery. The scale and direction of these changes merit further investigation.

REPRODUCCIÓN Y CULTIVO LARVARIO DEL PEZ PAYASO MARRÓN (Premnas biaculeatus) BAJO CONDICIONES CONTROLADAS

<p><strong>Background:</strong> Interest in ornamental marine fish, especially species associated with coral reefs, is rapidly growing. Most of the fish traded come from the wild, and collection methods harm coral reefs and cause massive mortalities in non-target species. To make the activity sustainable, it is necessary to develop aquaculture biotechnologies to reduce the collection of wild organisms and lessen the pressure on their natural environment. <strong>Objective:</strong> To develop protocols for the reproduction and larval rearing of the maroon clownfish (<em>Premnas biaculeatus</em>) for the sustained production of juveniles in captivity. <strong>Methodology:</strong> Two pairs of <em>P. biaculeatus</em> were placed in two aquariums of a recirculating system with filtered seawater. The obtained eggs were incubated in 100 L tanks. The larvae were fed with rotifers <em>Brachionus rotundiformis</em>, <em>Artemia</em> sp. nauplii, and weaned onto a commercial diet. The larvae were measured at hatching and every four days until weaning. <strong>Results:</strong> The clownfish pairs began spawning 4-5 months after being placed in the recirculating system and continued spawning every 15-20 days. The eggs hatched 6-7 days after fertilization (DAF), and the hatched larvae measured 3.4±0.06 mm in total length (TL). At 19 days after hatching (DAH), after completing weaning, they measured between 9.8 to 11.5 mm in TL; at 26 DAH, they measured between 10.8 to 13.1 mm. After one month, between 800 to 1,000 juveniles were obtained for commercialization. <strong>Implications:</strong> The reproduction and larval rearing protocols of the maroon clownfish <em>P. biaculeatus</em> described in this work can be used to obtain juveniles in captivity for commercialization; additionally, they can serve as a basis for developing other protocols for obtaining juveniles of other ornamental marine fish species for commercialization, contributing to the protection of their natural environment. <strong>Conclusion:</strong> The results obtained demonstrated the viability of maintaining <em>P. biaculeatus</em> breeders in captivity and achieving their natural reproduction, larval rearing, and mass production of juveniles throughout the year.</p>

Effects of Cryptorchidism on the Semen Quality of Giant Pandas from the Perspective of Seminal Plasma Proteomics

Giant pandas are an endangered species with low reproductive rates. Cryptorchidism, which can negatively affect reproduction, is also often found in pandas. Seminal plasma plays a crucial role in sperm–environment interactions, and its properties are closely linked to conception potential in both natural and assisted reproduction. The research sought to identify seminal fluid protein content variations between normal and cryptorchid giant pandas. Methods: Using a label-free MS-based method, the semen proteomes of one panda with cryptorchidism and three normal pandas were studied, and the identified proteins were compared and functionally analyzed. Results: Mass spectrometry identified 2059 seminal plasma proteins, with 361 differentially expressed proteins (DEPs). Gene ontology (GO) analysis revealed that these DEPs are mainly involved in the phosphate-containing compound metabolic, hydrolase activity, and kinase activity areas (p ≤ 0.05). The KEGG functional enrichment analysis revealed that the top 20 pathways were notably concentrated in the adipocyte lipolysis and insulin metabolism pathway, with a significance level of p ≤ 0.05. Further analysis through a protein–protein interaction (PPI) network identified nine key proteins that may play crucial roles, including D2GXH8 (hexokinase Fragment), D2HSQ6 (protein tyrosine phosphatase), and G1LHZ6 (Calmodulin 2). Conclusions: We suspect that the high abundance of D2HSQ6 in cryptorchid individuals is associated with metabolic pathways, especially the insulin signal pathway, as a typical proteomic feature related to its pathological features. These findings offer insight into the ex situ breeding conditions of this threatened species.

Gone with the flow: Whitefish egg drift in relation to substrate coarseness under a range of flow velocities.

Most major rivers in Europe have been dammed for hydropower or other purposes. Such river alterations have decimated natural reproduction of many migratory fish species, including that of the anadromous European whitefish, Coregonus lavaretus, which is now maintained by extensive stocking programmes. In addition to stocking, limited natural reproduction may occur downstream of dams, where peak flow bouts from the dams threaten to flush the eggs into unsuitable habitats. Here, we assessed the effects of water flow velocity and substrate coarseness on downstream drift of whitefish eggs under laboratory conditions. The experiment's two different gravel substrates retained eggs better than cobble or sand substrates; the water velocity needed for notable egg drift was higher for the gravel substrates. The results indicate that egg drift is one of the factors that should be considered when evaluating the effects of hydropower plant operations. Moreover, measures mitigating the effects of the artificial flow regimes should incorporate the type and coarseness of the riverbed's substrate.

Performance and cost advantage of stocking locally sourced Walleye fry into southern Minnesota lakes

AbstractObjectiveA genetically distinct strain of Walleye Sander vitreus (southern Minnesota strain [SMS]) persists in southern Minnesota lakes despite decades of stocking more easily obtained strains from outside of the region. Because of the regional performance advantage inferred by this persistence, we conducted in situ experiments to compare survival and stocking cost of SMS Walleye fry against those of a frequently stocked northern Minnesota strain (Mississippi headwaters strain [MIS]) to determine whether it is beneficial to expand SMS fry stocking in lieu of historic practices.MethodsWe conducted four paired stockings of oxytetracycline‐marked SMS fry and MIS fry into six southern Minnesota lakes and then sampled the fish as fall fingerlings during 2018, 2019, 2021, and 2022. We then used fluorescent microscopy and parentage‐based tagging techniques to discern the stocked strains for comparison of growth and survival. We also obtained production and stocking cost data from agency records to calculate relative stocking costs.ResultBy the end of their first summer, SMS Walleye from all but two stockings exhibited higher survival than MIS Walleye. Despite higher initial costs to produce SMS fry, their higher survival to fall fingerlings made the stocking of SMS fry more cost effective than MIS fry stocking. Natural reproduction was also identified in several stocked lakes, most of which consisted of either high or increasing levels of SMS ancestry.ConclusionA local strain can outperform nonlocal strains at a level that can overcome additional costs of developing a new egg source. In addition, natural reproduction of local‐strain Walleye may reduce or eliminate the need for future stocking.

Lake Superior fish community and fisheries, 2001–2022: An era of stability

Lake Superior is the least anthropogenically impacted of the Laurentian Great Lakes ecosystems, yet dramatic changes to the fish community are evident. Previous published works chronicled those changes and the efforts to rehabilitate the fish community through the year 2000. Here, we review through the year 2022, where post-rehabilitation stability was driven by lean lake trout (Salvelinus namaycush namaycush) as the most abundant piscivore in nearshore waters, siscowet lake trout (Salvelinus namaycush siscowet) as the most abundant piscivore in offshore waters, and a healthy, intact assemblage of native prey species, which created ecological redundancies and helped stabilize the food web. Stocking of non-native salmonines was reduced 74%, and populations of Chinook salmon (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch) were maintained through natural reproduction. Despite reduced stocking, yield from recreational fisheries was stable. Likewise, developments in population modeling led to evaluations and refinement of management strategies that helped create stability for lake trout, lake whitefish (Coregonus clupeaformis), and cisco (Coregonus artedi) fisheries. With lake trout rehabilitation achieved, focus shifted toward rehabilitation of native brook trout (Salvelinus fontinalis), lake sturgeon (Acipenser fulvescens), and walleye (Sander vitreus). Despite continued control efforts, sea lamprey (Petromyzon marinus) abundance increased considerably, and estimates of fish killed by lampreys averaged 2.65 million kg annually. Environmental changes have benefited sea lampreys and fostered thermal habitats more suitable to non-native organisms, posing new challenges for managers and researchers. Nevertheless, the post-rehabilitation stability in the contemporary fish community will help provide resilience to future perturbations in the ecosystem.

Evaluation of potential factors affecting the success of Cisco re-introduction and re-establishment in Lake Huron

Recent food web changes led to an opportunity to reintroduce (fingerling stocking) Cisco in central Lake Huron. We examined 9 factors affecting the ability of stocked Cisco fingerlings to survive, and reproduce and for their progeny to survive and reproduce. These values (obtained from the literature) were applied to a stochastic Leslie Matrix model and projected forward 30 years. The mean terminal eigenvalue (λ) of the final 10 years was used to indicate if the resulting wild population would continue to increase or decrease and thresholds for each variable. Recovery success was sensitive to survival rates especially in early life stages. Numbers stocked and the rate of homing by hatchery fish only affected the rate of recovery. Adult survival, if adjusted up, helped compensate for many of the earlier life stages lower survival rates. Simulations indicated the likelihood of successful establishment of ongoing natural reproduction if periodicity of boom years of reproduction were at least once every 5 years on average, but higher adult survival rates can relax this requirement allowing for an expanding population at less frequent periodicities.

Study on the key ecological factors for the reproduction of Gymnocypris eckloni in the upper reaches of the Yellow River.

The development of hydroelectric projects has adversely affected the reproductive activities of downstream fish species. To facilitate the natural reproduction of fish and restore spawning grounds post-dam construction, it is imperative to explore the ecological factors crucial for their reproduction. Currently, various research methods with different advantages and limitations are employed for this purpose. Using identified spawning locations and periods as clues, we quantitatively investigate the flow velocity, water depth, water temperature, and riverbed substrate required for spawning. The results are validated using habitat simulation methods, aiming to establish a more scientific approach to explore ecological factors affecting fish reproduction. This study provides a more scientific, systematic, and detailed report on the ecological factors required for the spawning of Gymnocypris eckloni: flow velocity ranging from 0.19 to 0.97 m/s, water depth from 0.28 to 1.12 m, water temperature between 11.4 and 15.2°C, and predominantly gravel substrate. The reliability of the results was verified in another spawning ground, with good verification results. This research provides crucial data for the bio-mimetic reproductive technology of Gymnocypris eckloni and the restoration of spawning grounds for natural fish reproduction post-dam construction. It addresses the lack of suitable ecological factor data for protective fish species in the upper reaches of the Yellow River. The method exhibits strong scientific, accurate, and implementable characteristics.

Patterns of molecular evolution in a parthenogenic terrestrial isopod (Trichoniscus pusillus).

The "paradox of sex" refers to the question of why sexual reproduction is maintained in the wild, despite how costly it is compared to asexual reproduction. Because of these costs, one might expect nature to select for asexual reproduction, yet sex seems to be continually selected for. Multiple hypotheses have been proposed to explain this incongruence, including the niche differentiation hypothesis, the Red Queen hypothesis, and accumulation of harmful mutations in asexual species due to inefficient purifying selection. This study focuses on the accumulation of mutations in two terrestrial isopods, Trichoniscus pusillus, which has sexual diploid and parthenogenic triploid forms, and Hyloniscus riparius, an obligately sexual relative. We surveyed sex ratios of both species in an upstate New York population and obtained RNA-seq data from wild-caught individuals of both species to examine within- and between-species patterns of molecular evolution in protein-coding genes. The sex ratio and RNA-seq data together provide strong evidence that this T. pusillus population is entirely asexual and triploid, while the H. riparius population is sexual and diploid. Although all the wild T. pusillus individuals used for sequencing shared identical genotypes at nearly all SNPs, supporting a clonal origin, heterozygosity and SNP density were much higher in T. pusillus than in the sexually reproducing H. riparius. This observation suggests this parthenogenic lineage may have arisen via mating between two divergent diploid lineages. Between-species sequence comparisons showed no evidence of ineffective purifying selection in the asexual T. pusillus lineage, as measured by the ratio of nonsynonymous to synonymous substitutions (dN/dS ratios). Likewise, there was no difference between T. pusillus and H. riparius in the ratios of nonsynonymous to synonymous SNPs overall (pN/pS). However, pN/pS ratios in T. pusillus were significantly higher when considering only SNPs that may have arisen via recent mutation after the transition to parthenogenesis. Thus, these recent SNPs are consistent with the hypothesis that purifying selection is less effective against new mutations in asexual lineages, but only over long time scales. This system provides a useful model for future studies on the evolutionary tradeoffs between sexual and asexual reproduction in nature.

Generic color correction for tone mapping operators in high dynamic range imaging.

One of the significant challenges in tone mapping is to preserve the perceptual quality of the tone-mapped images. Traditional tone mapping operators (TMOs) compress the luminance of high dynamic range (HDR) images with little to no consideration of image color information resulting into suboptimal colors. Existing color management algorithms require either manual parameter tuning or introducing lightness and hue shifts. The current study aimed to develop a color correction model in plausible agreement with the psychophysical phenomenon of color appearance perception for optimal color reproduction of tone mapped images. The proposed model leverages CIECAM16 perceptual correlates i.e., lightness, chroma, and hue. It is adaptive and entirely automatic while preserving the lightness of the tone-mapped image and maintaining the hue from the HDR image. Moreover, it does not require any gamut mapping correction algorithm in natural color reproduction. The effectiveness of the model was validated using objective and subjective methods. The experiments revealed that the model achieved optimal color reproduction in terms of the naturalness of the colors.

Current state and analysis of the demographic situation of the Republic of Kazakhstan

This article examines the current demographic situation of the Republic of Kazakhstan in the context of the quality of human potential and the increase in the effi ciency of human resources. Purpose of the research. This study aims to comprehensively analyse the current demographic situation in the Republic of Kazakhstan, highlight the country's leading trends and challenges, and off er recommendations for improving demographic policies and practices. Methodology. The research methods are economic-statistical and correlation-regression analyses. The article also uses general methods of understanding reality: generalisations, comparisons, and descriptions. Originality / value of the research. The authors analysed the statistical data of the population of Kazakhstan for the period from 2012 to 2023 in the context of structural changes and geographical conditions. Authors also conducted a comparative analysis of natural growth in individual countries and the Republic of Kazakhstan. Findings. The critical factors of fertility and natural population growth have been identified. Attention is paid to the country's changing demographic profi le in connection with economic, social, and political transformations. A list of legal acts determining the country's demographic policy today is presented. Acorrelation and regression analysis of factors such as gdp per capita and the average amount of assigned state social benefi ts was carried out. The authors also present a diagram that forms the environment for family planning and population reproduction. This scheme consists of elements that determine the process of natural reproduction in the Republic of Kazakhstan. Conclusions and practical recommendations based on the study results are presented, and further directions for an in-depth study of this topic are outlined. The article also emphasises the need for an integrated approach to implementing demographic policy in the country.

P-042 Enhancing human sperm motility using high-frequency ultrasound

Abstract Study question Is high-frequency ultrasound effective in the treatment of low-motility sperm for use in assisted reproduction? Summary answer Our study reveals that immotile and poorly motile sperm respond to ultrasound treatment and show up to 266% boost to motility parameters upon ultrasound exposure What is known already Sperm motility is central to both natural and assisted reproduction. This crucial importance has led to the utilization of chemical drugs such as pentoxifylline, theophylline, and other phosphodiesterase inhibitors to improve motility. However, these drugs are embryotoxic with a potentially harmful effect on sperm longevity. In a recent study, we showed that sperm cells at the population level showed a 32% boost to motility after 15 seconds of exposure to ultrasound. However, to translate these findings into clinical applications, it is crucial to identify which subset of sperm within a population is most affected by the treatment. Study design, size, duration We conducted single-cell study aimed at comprehensively assessing how different sperm motility grades are affected by ultrasound exposure. We utilized a droplet acoustofluidic system using which sperm cells were isolated in droplets and their responses to ultrasound were monitored. A total of 239 individual sperm from three biologically independent human samples were included in this study and parameters such as sperm motility, viability, DNA integrity, and mitochondrial membrane potential (MMP) upon ultrasound exposure were analysed. Participants/materials, setting, methods Fresh human semen samples were collected from healthy donors with the approval of the Monash University Human Research Ethics Committee. Three human donors contributed to a total of sixteen independent experiments performed in this work. The manual tracking plugin in ImageJ was used to measure sperm motility. The LIVE/DEAD™ Sperm Viability Kit (Invitrogen, USA) was used to evaluate sperm viability and JC-1 (Invitrogen, USA) was used to monitor the MMP. Main results and the role of chance We classified the sperm cells based on their pre-exposure straight-line velocity (VSL) into three categories of grade C (non-progressive, VSL < 5 µm s-1), grade B (slow progressive, 5 ≤ VSL< 25 µm s-1), and grade A (rapid progressive, 25 µm s-1 ≤ VSL) cells. Our single-cell analysis results show that 20 seconds of ultrasound exposure boosts the motility of grade C sperm up to 266% and as a result, 90% of total sperm are graded as progressively motile after exposure. Through ANOVA tests, we showed that non-progressive sperm cells show a boost to all of the motility parameters more than the other grades. In addition, ultrasound exposure renders 34% of live immotile sperm motile with 24% of the cells graded as progressive and the remaining 10% showed a twitching motility after exposure. We also showed that ultrasound exposure induces flagellum deformation to 16% of total live immotile sperm cells, providing opportunities to detect live sperm in testicular samples using this approach. Finally, we explored the non-invasiveness of the ultrasound platform and showed that there is no detrimental effect on sperm DNA integrity and viability post exposure. Limitations, reasons for caution A larger sample size could provide a higher statistical confidence to our study. Treatment of patient samples (testicular or asthenozoospermic) and evaluation of embryo safety must be included in future studies to evaluate the effectiveness of this method for clinical use. Wider implications of the findings Our acoustic mechanotherapy method could enhance sperm motility to potentially benefit assisted reproduction outcomes. It also enables new opportunities for detecting live sperm in testicular samples. Trial registration number not applicable

P-033 Microfluific sperm sorting does not impact the primary sex ratio in IVF-ICSI treatments

Abstract Study question Does sperm selection through microfluidics alter the primary sex ratio (PSR) when compared to density gradients? Summary answer The PSR is not modified when employing a microfluidic sperm sorting when comparing to the conventional density gradient technique for sperm selection. What is known already The PSR refers to gender after fertilization, this is often expressed as the male births per female births. Little is known about the sex ratio in natural and assisted reproduction treatments (ART) since it is difficult to establish in ART as it requires preimplantation genetic testing (PGT). Previous studies have been estimating the variation in the PSR based on the fertilization technique used or the day of embryo transfer. Even the influence of sperm selection techniques has not received much attention, using traditional sperm selection methods such as density gradients or swim-up, a PSR of 1.07 has been estimated. Study design, size, duration This is a retrospective study that includes 1764 blastocysts stage embryos biopsied from 522 autologous preimplantation genetic testing for aneuploidies cycles (PGT-A) performed between January of 2020 and December of 2022 and analysed through Next Generation Sequencing (NGS). All the embryos were cultured under the same conditions with one-step media in a time-lapse incubator and the PGT-A was performed in day 5 or day 6 of culture to determine the embryo ploidy status. Participants/materials, setting, methods Two groups were established based on the sperm selection method before ICSI. The study group using a microfluidic system (MS; ZyMōtICSI® or ZyMōtMulti®) included 256 blastocysts from 98 cycles, and a control group using density gradients (DG), with 1058 blastocysts from 424 cycles were compared. PGT-A determined the embryonic sex and for the PSR estimation, number abnormalities in the sexual chromosomes were excluded (i.e. XXY, X0, XYY). Chi-square test was performed to compare the groups. Main results and the role of chance Our data show that there was no statistical significance in the overall ratio of XY:XX embryos biopsied between both groups (p = 0.09). The PSR was 0.89 (47:53) in the study group (MS) and 1.12 (53:47) in the control group (DG). Although not statistically significant, the rate of XX embryos was 6% higher than XY embryos in the MS group. In contrast, in the DG group, the same increase in the rate of XY embryos was observed. If we consider only the euploid embryos which are the potentially born babies, the PSR acquires values of 0.96 for the DG group and 0.92 for the MS group (p = 0.86), showing an increase in euploid female embryos transferred compared to those euploid male embryos. However, it was not statistically significant. Limitations, reasons for caution The performance of PGT-A on blastocysts does not provide an entirely accurate representation of the PSR since it is carried out 5/6 days after the moment of fertilization; nevertheless, it is the technique that comes closest. Also, the low number of blastocysts in the study group represents a limitation. Wider implications of the findings The sperm selection for ICSI with microfluidic technology does not significantly alter the PSR. Trial registration number Not applicable

Rearing of European catfish (Silurus glanis L.) in earthen ponds in polyculture with common carp larvae (Cyprinus carpio L.)

The aim of the present study is the production of stocking material of European catfish (Silurus glanis L.) using common carp larvae (Cyprinus carpio L.) as natural food source. The experiment was carried out in two earthen ponds (№18 and №19). The stocking material was produced through semi-artificial reproduction of European catfish and natural reproduction of common carp in two stages. The main aquaculture production indicators of the stocking material of European catfish and common carp were calculated: growth (WG, g), survival (%), total yield (kg) and average yield (kg/1000 m2). The obtained results show that the growth of European catfish in pond №19 is 69.67 g, while in pond №18 it is 58.91 g. Also, the survival rate in pond №19 is 2.8 times higher than in pond №18. After analyzing the obtained results, it can be concluded that the production indicators of the European catfish stocking material are higher in experimental pond №19.

Xenobiotics and pollution of Lake Ladoga

Advances in applied chemistry have led to the emergence of a new group of organic toxicants - xenobiotics, which have found wide application in industry, agriculture and everyday life, and quickly spread through the biosphere, exerting a prolonged effect on living organisms, including humans. Research was carried out in the waters of the Shlisselburg, Volkhov and Svirskaya lips of the littoral zone of the southern part of Lake Ladoga in the period 2020-2023, using generally accepted methods of biological and chemical analytical analysis of fish and their habitat. 1500 specimens were examined. Fish and 3000 larvae. Chemical-analytical studies of samples of water, bottom sediments, atmospheric precipitation and fish for metals were carried out in the laboratory of fishery ecology of the St. Petersburg branch of the Federal State Budgetary Institution "VNIRO" ("GosNIORH" named after L.S. Berg) on an atomic absorption spectrophotometer AA - 7000 (Shimadzu) according to approved methods (PNDF., 2010; M02-2406., 2013 and M02-902-125, 2005), and in the research laboratory of food and natural objects "ANALECT" of the Institute of the Ministry of Health of the Russian Federation, using the method of atomic absorption spectrometry according to approved methods. Hydrochemical and hydrological indicators were determined using an automatic multiparameter probe Aqua TROLL 500. The content of metals in the fish habitat at the surveyed equators, as dangerous toxicants and previously significant for Lake Ladoga, showed their low content and especially such highly toxic ones as lead and cadmium. Minor excesses were noted for copper and manganese, but they could not in themselves be the cause of pathological manifestations of toxicosis in fish and disruption of the process of their natural reproduction.

Physiological and biochemical studies of young sterlet sturgeon (Acipenser ruthenus L.) in the lower reaches of the Volga river

In conditions of a decrease in the number of rolled sturgeon larvae in the lower reaches of the Volga River, an urgent issue is the study of the physiological and biochemical parameters of the fish organism. The purpose of this work is to conduct physiological and biochemical studies of juvenile sterlet (Acipenser ruthenus L, 1758). The study of fish was carried out using the methods of classical histology and biochemistry. The degree of damage to the gills and liver was assessed on a scale from 1 to 5 points. The content of total lipids and water-soluble protein in the muscle tissue of sterlet fingerlings was studied as biochemical parameters. The morphological picture of the gills of 80% of the fish corresponded to a weakly pronounced character of changes (2 points), while in others it was characterized by the presence of a borderline state between weakly pronounced changes and moderate injuries (2–3 points). Six types of disorders were found in the gills: hyperplasia of the respiratory epithelium of lamellae, dilation of the blood vessel of the filament, goblet-shaped swellings of the apical part of the filament, invasions, expansion of the apical part of the lamellae, proliferation of connective tissue of lamellae. In the liver of 80% of fish, a borderline state was recorded between mild changes and moderate damage (2–3 points), in 13.3% of individuals the liver had mild damage (2 points), in 6.7% there were medium damage (3 points). Four types of disorders were found in the liver of juvenile sterlet: fullness of the liver capillaries, pronounced venous fullness, cavities, capillary dilation. In the muscle tissue of fingerlings, the concentrations of total lipids were in the range of 1.39–5.28%, and water-soluble protein — 45.59–57.97 mg/g. The study of the physiological and biochemical parameters of juvenile sturgeon in the lower reaches of the Volga River is very important for the biology of the species and monitoring the natural reproduction of these valuable fish species.

Color Biomimetics in Textile Design: Reproduction of Natural Plant Colors through Instrumental Colorant Formulation.

This paper explores the intersection of colorimetry and biomimetics in textile design, focusing on mimicking natural plant colors in dyed textiles via instrumental colorant formulation. The experimental work was conducted with two polyester substrates dyed with disperse dyes using the exhaustion process. Textiles dyed with different dye colors and concentrations were measured in a spectrophotometer and a database was created in Datacolor Match Textile software version 2.4.1 (0) with the samples' colorimetric properties. Colorant recipe formulation encompassed the definition and measurement of the pattern colors (along four defined natural plants), the selection of the colorants, and the software calculation of the recipes. After textile dyeing with the lowest expected CIELAB color difference (ΔE*) value recipe for each pattern color, a comparative analysis was conducted by spectral reflectance and visual assessment. Scanning electron microscopy and white light interferometry were also used to characterize the surface of the natural elements. Samples dyed with the formulated recipe attained good chromatic similarity with the respective natural plants' colors, and the majority of the samples presented ΔE* between 1.5 and 4.0. Additionally, recipe optimization can also be conducted based on the colorimetric evaluation. This research contributes a design framework for biomimicking colors in textile design, establishing a systematic method based on colorimetry and color theory that enables the reproduction of nature's color palette through the effective use of colorants.

Anadromous sturgeon fish of the Azov Sea under conditions of natural and anthropogenic transformations of the water ecosystem

The aim: assessment of the state of populations of anadromous sturgeon in the Sea of Azov, the efficiency of their reproduction and the possibility for the existence of populations in the medium term until 2030–2040. Methods: the calculation of the biomass and population size of sturgeon in the Sea of Azov was carried out using the direct counting method and a modified cohort solution of the Baranov equation. 18and 25-meter bottom trawls were used as standard fishing gear. The assessment of the number of juvenile sturgeon in the Don River was carried out with 3and 2-meter beam-trawls. Molecular genetic methods for the analysis of microsatellite loci and sequencing of a fragment of the control region of mitochondrial DNA were used.Novelty: materials are presented on natural reproduction of sturgeon in the Don River after flow regulation, and the rate of decline in the survival rate of generations of Russian sturgeon and stellate sturgeon under the influence of illegal fishing is shown. Based on the results of a study of the genotypes of Russian sturgeon individuals, migrations sturgeon from Azov to the Black Sea, as well as Black Sea populations to the Sea of Azov, were confirmed.Results: an analysis of the dynamics and current state of anadromous sturgeon in the Sea of Azov is presented under the conditions of anthropogenic transformation of their habitat, loss of natural reproduction and climate-related fluctuations in the salinity of the sea waters. A retrospective overview of their commercial use from the mid-19th century to the present is given. The prospects for restoring commercial stocks of sturgeon fish are considered.Practical significance: the possibility of restoring commercial stocks of sturgeon in modern conditions is shown by increasing the number of released juveniles and increasing the effectiveness of fish conservation measures to a level of more than 90 thousand tons and creating an commercial population of sturgeon in the Sea of Azov.

The state of spawning grounds, a study of the biology and population dynamics of pacific salmon on Kunashir Island (Southern Kuril Islands) in 2023

The purpose: formation of scientific foundations for improving the efficiency of salmon management on Kunashir Island (South Kuril zone) to ensure the sustainable exploitation of the commercial stock of Pacific salmon, maintain the necessary level of their reproduction, preserve the habitat, as well as improve scientific approaches to forecasting commercial catches.Methods used: the work was carried out in accordance with the methods generally accepted in fisheries research.Result: information was obtained on the dynamics of Pacific salmon entry, the filling of spawning grounds and the state of reservoirs on Kunashir Island. The collection of materials characterizing the biological indicators of chum salmon producers was carried out. Statistical information was obtained on catches of chum salmon and artificial reproduction of salmon fish on Kunashir Island.Practical significance: information on the filling of the spawning grounds of Pacific salmon on Kunashir Island and the quality indicators of their producers will be used to substantiate fishing regulation measures. Data on the state of artificial and natural reproduction of Pacific salmon are intended to develop a strategy for the development of artificial reproduction on Kunashir Island.