Fish Mass Research Articles

Implications of climate change on freshwater ecosystems and their biodiversity

Global warming is a phenomenon whereby the planet's exposure to the sun's radiation worsens from the high emission of gasses believed to trap heat within the atmosphere. Carbon dioxide (CO2) is the leading greenhouse gas majorly responsible for global warming and other related issues and is a danger to global society. This one has a particular role in portraying the key importance of the shifting climate that invariably influences water supply and agricultural production. Global warming presents complex challenges to aquatic organisms and stocks and other natural aquatic life resources. This study examines how freshwater and marine species are affected by climate change in aquatic habitats. Aquatic species' metabolism, growth, reproduction, and dispersal are all impacted by rising temperatures and altered water chemistry brought on by increased greenhouse gas emissions, especially CO2. The goal is to pinpoint the ecosystems and vulnerable species that are most impacted by these changes and suggest flexible management techniques. The suggested remedies center on creating sustainable conservation strategies that lessen the effects of climate change on aquatic biodiversity and increase these ecosystems' resilience. The socio-economic interdependencies between water and climate change impact agricultural and water resources, and the pressures exerted on water bodies and water supply landscapes. Another area is related to alterations in the physical and chemical properties of the water, such as the temperature, which is a well-known effect of climate change: 'This causes abnormalities in the metabolism and physiology of aquatic species.' These alterations flow through the chain and regime of growth, reproduction, feeding habits and distribution, migration, and mass of fish and other creatures in the water system. However, the long-term effect of climate variation and climate change on freshwater ecosystems requires much scientific investigation to address challenges in aquatic ecosystem conservation and sustainability. This being the case, adaptive management solutions that address the interrelated impacts of climate change have to be applied and implemented to reduce vulnerability in aquatic ecosystems worldwide.

Relationships between body length, body mass and otolith dimensions in three Sprat species (Teleostei: Ehiravidae) from the Caspian Sea

AbstractReliable and detailed knowledge regarding the relationship between otolith size and the size of fish is important for fisheries management and for ecological studies on predicting fish size and on predator–prey interactions. Therefore, these relationships are estimated for three sprat (genus Clupeonella) species, including C. caspia, C. engrauliformis and C. grimmi from the Caspian Sea. The relative size and mass of the otoliths corrected for body size and mass were also estimated for the three sprat species. After biometry of collected specimens, the Sagittal otoliths were extracted from the cranium of collected specimens and photographed. Photos were used to estimate length and width of otoliths. The results revealed significant relationships between otolith length and width vs. fish length and otolith mass vs. body mass in all three species (r2 > 0.5). The higher coefficient of determination (r2) for relationships between total length (fish) – Otolith length and width was concluded in comparison with relationships between fish mass and otolith mass in the studied sprat species. Otoliths of C. grimmi showed the highest relative length and were significantly (P < 0.05) heavier than sagittal otoliths of two other sprat species. There is no previous report on size–mass relationships between fish and otolith measurements among the three studied sprat species. These estimated equations can be used in back-calculation studies, especially for these three sprats as the dominant prey for piscivorous predators such as Caspian seals and sturgeons, in their habitats.

Antidiabetic potential of sea fish mass by inhibiting di-peptidyl peptidase-IV and augmenting glucagon-like peptide-1 on high lipid diet and streptozotocin induced diabetic rats

Many studies have revealed that sea fish is a rich source of nutrients, especially protein and there peptide. In this study, antidiabetic activity of the fish masses of three sea-fishes ‘volavetki’ (Panna microdon, Bleeker 1849), ‘ruli’ (Coilia dussumieri, Valenciennes 1848), ‘tapra’(Opisthopterus tardoore, Cuvier 1829) and one fresh-water fish ‘murola’(Amblypharyngodon mola, Hamilton 1822),evaluated high lipid diet (HLD) and STZ induced Type 2 Diabetic Mellitus (T2DM) rats. Supplementation of sea-fish masses and antidiabetic effect was monitored by fasting plasma blood glucose and HbA1c. Also, insulin, c-peptide, glucagon-like peptide-1, dipeptidyl peptidase-IV, glucokinase, glucose-6 phosphatase, superoxide dismutase, glutathione peroxidase, catalase, plasma total cholesterol, low density lipoprotein, triglycerides, high density lipoprotein and histopathology of free radical activity of pancreatic tissues were evaluated. Out of four fish masses, volavetki sea fish masses oral supplementation resulted in significant reduction of plasma blood glucose, HbA1c of T2DM rat. All other parameters in T2DM rats were returned to near normal by treatment of volavetki sea fish mass. Our findings strongly indicated that volavetki sea fish highly showed antidiabetic activity.

Design and development of a new stand-alone profiler for marine monitoring purposes

Marine pollution is a complex issue that has prompted extensive research. The Mar Menor lagoon, a singular Mediterranean ecological feature, is under pressure from various economic activities, leading to episodes of hypoxia and fish mass mortality. The lagoon is covered by an extensive meadow of submerged vegetation that release oxygen during daylight hours but consumes it during the night. Under exceptional conditions, the water column becomes stratified, with higher oxygen consumption in the deeper layers due to organic matter decomposition. Therefore, continuous high-frequency monitoring of critical parameters affecting the metabolic behaviour of the lagoon is essential. This marine environment has traditionally been monitored with traditional techniques from vessels on a weekly basis, incurring in high costs and yielding limited results. This article introduces the s-Nautilus, a submersible profiler that enables near real-time data transmission in shallow marine environments. It showcases an operational autonomy of two months and significantly reduces installation costs by eliminating the need for on-site infrastructure and personnel. Weighing 21 kg, makes it easy to transport, and it can be equipped with different commercial sensors to monitor various parameters as required. Currently, several s-Nautilus profilers are deployed in the Mar Menor lagoon, collecting data during critical hours, and providing valuable information to the managers of this emblematic environment.

Comparison of fish biological indicators of Clarias gariepinus hybrids grown in ras and pond farming conditions

To improve technologies in the field of commercial cultivation of aquaculture objects and further development of the warm-water aquaculture sector in Russia, we previously undertook breeding methods and approaches to obtain high-quality planting material for a promising commercial object — the African catfish Clarias gariepinus. This article presents, in a comparative aspect, the experience of growing hybrid offspring of African catfish, obtained from crossing two breeds — Mikhailovskaya and Tamanskaya, in a closed water supply system and in a pond farm in the Astrakhan region in the summer. It was shown that hybrid individuals of clariid catfish bred in a pond farm during the feeding period under consideration (from July to September) were characterized by a high specific growth rate and low feed ratio compared to hybrids grown in a recirculation system, respectively, 11.4% versus 9.87% and 0.96 versus 1. Also, based on the results of fishing, over two months of cultivation in a pond farm, hybrids of clariid catfish increased the total biomass by 13 times, while in a recirculating system it increased by 15 times, but the final biomass of fish turned out to be greater when reared in open reservoir (46.875 versus 10.87 kg). It was shown that the final individual mass of hybrid fish cultured in pond conditions was 11.0% higher than the final mass of individuals in the recirculation system. The conducted studies showed that in the climatic conditions of the Astrakhan region (VI fish-breeding zone), a promising direction for aquaculture of African catfish is the feeding cultivation of hybrid juveniles in pond farms. It should be taken into account that in order to obtain marketable fish products (i.e. individuals weighing over 1000 g), it is necessary to use fish seeding material with an average weight of at least 100 g.

Characteristics and radiological hazard assessment of 210Po in tilapia (Oreochromis niloticus) in Vietnam.

210Po is one of the most toxic natural radionuclides. This isotope's characteristics and radiological hazard assessment have been concerned in different objects. In this study, the 210Po activities were determined in different tilapia organs/parts of 20 sample groups by alpha spectrometry. The 210Po activities in muscle, bone, intestine organs, and stomach contents unevenly distributed with a wide range from 0.5 ± 0.2 to 2.8 ± 0.4 and 1.4 ± 0.2Bq·kg-1 wet.wt on average, from 0.6 ± 0.3 to 6.3 ± 0.7 and 3.5 ± 0.4Bq·kg-1 wet.wt on average, from 46.3 ± 2.9 to 263 ± 9.7 and 115 ± 6Bq·kg-1 wet.wt on average, and 20.9 ± 1.2 to 800 ± 29 and 197 ± 9Bq·kg-1 wet.wt on average, respectively. The average 210Po activities in different parts of tilapia trend in order of CMuscle < CBone < CIntestine < CStomach contents. Insignificant correlations were observed between 210Po activities in tilapia organs with their total fish mass. The result could depend on feeding types, diet, different nutrient levels, metabolism, and excretion of 210Po in different ages. The concentration ratios (CRs) of tilapia muscle and bone organs were recorded with low values, while it was far greater than the CRs for the intestine organ. Annual committed effective doses contributing from 210Po concentration due to tilapia fish consumption were within the allowable limits for muscle and bone organs, while those values for intestine organs were far higher than the allowable limit value (assuming similar amount consumption of 30kg·year-1 for each organ). The Erica tool was used to estimate the dose and risk to tilapia from 210Po exposure. Based on the calculated results, it can be seen that there was insignificant concern for tilapia due to ionizing radiation in the study area.

Evaluation of a gel-based versus micro-pellet diet for adult zebrafish (Danio rerio).

Ad libitum feeding of laboratory zebrafish has potential benefits for colony management, but would require a new type of diet, such as a gel that remains in the tank. We hypothesized that adult zebrafish fed a gel diet would have similar body size and reproductive success compared with those fed a standard micro-pellet diet. The gel diet’s impact on water quality was determined to be safe for zebrafish prior to starting a 12-week feeding study. Two hundred adult AB zebrafish of mixed sex were randomly assigned to be fed exclusively either gel or micro-pellet diet. Fish body length and mass were measured every two weeks, and fish were bred within each feed group to assess fecundity. Zebrafish consumed less gel diet than expected. Body length, mass, and breeding success were lower in the gel diet fish than in the micro-pellet diet fish. Low consumption of the gel diet and/or nutritional differences between the two diets may have contributed to reduced growth and fecundity. Though the gel diet could reduce time personnel spend feeding and be safer for fish in static tanks, the tested formulation was not a satisfactory alternative to the control micro-pellet diet in a research zebrafish colony.

Study on the Biological Drug Enterocol’s Effect on the Nile Tilapia Breeding

Background Nile tilapia (Oreochromis niloticus) is a promising fish species for fish farming development in the Republic of Kazakhstan. It exemplifies a balanced and fast-growing source of flesh for future food production. In this context, optimising breeding methods is crucial for a high flesh yield and a safe product. The study delves into the potential of the Enterocol drug in enhancing Nile tilapia breeding, focusing on assessing muscle state and blood parameters. Objects Two groups of fish were utilized, with 20 specimens in each group. One set was the control group, and the other was the experimental group. The single difference between the fish groups was the Enterocol consumption by the experimental specimens, which were given an E. coli 64G strain concentration of 108 CFU in mL and a 5% daily dose of fish body weight three times daily for two months. Methods Blood parameters were analysed to assess the health of the fish groups. Subsequently, classical pathological methods were employed, such as macroscopic and microscopic assessments of each group's fish material. A histological analysis was also performed to assess the condition of the muscles. Results Examining the experimental group's muscles revealed a significant average increase in fish mass and 6.74% total body weight growth. Moreover, the total thickness of the muscle layer decreased as villi height increased, indicating a clear fibre structure. Haematological analysis unveiled elevated levels of haemoglobin, erythrocytes, leucocytes, and total protein in the experimental fish group, indicating improved health. These findings underscore the potential of the Enterocol drug in enhancing fish health and productivity. Conclusion Based on the results, it can be concluded that using Enterocol in fish breeding plants can effectively enhance flesh quality and safety, providing a secure and reliable solution for the aquaculture industry.

Underwater swimming fish mass estimation based on binocular vision

Underwater swimming fish mass estimation based on binocular vision

RUNGE–KUTTA LIKE METHOD FOR THE SOLUTION OF OPTIMAL CONTROL MODEL OF REAL INVESTMENT AND FISH MANAGEMENT

This study develops the Runge-Kutta Like Method (RKLM), which uses Pontryagin's principle to solve optimal control problems numerically using forward-backward sweep methods. It is based on the Patade and Bhalekar methodology. The RKLM's stability properties and its convergence are examined. The Forward-backward sweep algorithm and the RKLM algorithm are implemented using MATLAB code. Physical optimum control problems are solved with the RKLM. The first problem's conclusion demonstrates that, when investment declines, the capital first grow to boost production before it depreciates. The outcome of the second problem demonstrates that a larger weight parameter causes the harvesting rate to reach zero more quickly and the total fish mass to reach its maximum level more quickly. The findings obtained demonstrate the effectiveness of using RKLM in conjunction with forward-backward sweep methods to solve optimal control problems.

Characterization of adaptive expression regulation of yellowtail kingfish (Seriola lalandi) leptin, receptor, and receptor overlapping transcript genes in response to fasting and re-feeding strategies.

Leptins and other related genes have been proven to play vital roles in food intake, weight control, and other life activities. While the function of leptins in yellowtail kingfish (Seriola lalandi) has not yet been explored, in the present study, we investigated the structure and preliminary function of four leptin-related genes in S. lalandi. In detail, the sequence of two leptin genes (lepa and lepb), one leptin receptor gene (lepr), and one leptin receptor overlapping transcript (leprot) gene were obtained by homology cloning and RACE methods, in which lepa and lepb have similar structure. Moreover, homologous sequence alignment and evolutionary analysis of all four genes were clustered with Seriola dumerili. The tissue distribution of these four genes in thirteen tissues of yellowtail kingfish was detected by RT-qPCR. Both lepa and leprot were highly expressed in the brain and ovary, while lepb was highly expressed in the pituitary, gill, muscle, and ovary; lepr was highly expressed in the gill, kidney, and ovary. Additionally, these four genes also played roles in embryo development and early growth and development of larvae and juveniles of yellowtail kingfish. Finally, the function of leptin and leptin-related genes was investigated during fasting and re-feeding adaption of yellowtail kingfish. The results showed that these four genes have different regulation functions in five tissues; for example, the mRNA levels of lepa, lepr, and leprot in the brain decreased during fasting and immediately increased after re-feeding, while the mRNA level of lepb did not show significant fluctuation during starvation but significantly lowered after re-feeding. However, lepa and lepb mRNA levels were significantly elevated during fasting and returned to control levels after re-feeding, and there were no significant changes in the expression of lepr and leprot in the liver during fasting and after re-feeding. Moreover, the body mass of fish in the experimental group was measured, and compensatory growth was found after the resumption of feeding. These results suggested that leptin and receptor genes play different functions in different tissues to regulate the physiological state of fish in food deficiency and gain processes.

Accelerometer-based swimming metabolism of smallmouth bass (Micropterus dolomieu).

Bioenergetics is informative for a range of fundamental and applied resource management questions, but findings are often constrained by a lack of ecological realism due to the challenges of remotely estimating key parameters such as metabolic rate. To enable field applications, we conducted a calibration study with smallmouth bass (Micropterus dolomieu, 0.7-2 kg) surgically implanted with accelerometer transmitters and exposed to a ramp-Ucrit swimming protocol in a swim tunnel respirometer across a range of water temperatures (6, 12, 18, and 24°C). There was an exponential increase in fish acceleration with swimming speed, and acceleration per speed was higher in smaller fish and female fish, and at colder temperatures. Mass-specific fish metabolic rate (MO2; mg O2 kg-1 h-1) increased with swimming speed, acceleration, and temperature, and decreased with fish mass, which when combined were strong predictors of MO2. Maximum metabolic rate (MMR) was estimated to peak at 22°C, but maximum sustained swimming speed (Ucrit) remained high at c. 90-100 m s-1 above 20°C, based on second-order polynomial functions. Aerobic scope (AS) estimates peaked at 20°C (>90% AS at 17-24°C; >50% AS at 11-28°C). Males exhibited marginally higher MMR, AS, and Ucrit than females at higher temperatures. Larger fish generally exhibited higher Ucrit, but smaller fish had a marginally broader performance range (AS, Ucrit) among temperatures, benefiting from higher MMR despite a steeper increase in resting metabolic rate with temperature. These findings enable field studies to estimate metabolic metrics of smallmouth bass in situ to characterize their ecological energetics and inform bioenergetics models.

Non-Contact Tilapia Mass Estimation Method Based on Underwater Binocular Vision

The non-destructive measurement of fish is an important link in intelligent aquaculture, and realizing the accurate estimation of fish mass is the key to the stable operation of this link. Taking tilapia as the object, this study proposes an underwater tilapia mass estimation method, which can accurately estimate the mass of free-swimming tilapia under non-contact conditions. First, image enhancement is performed on the original image, and the depth image is obtained by correcting and stereo matching the enhanced image using binocular stereo vision technology. And the fish body is segmented by an SAM model. Then, the segmented fish body is labeled with key points, thus realizing the 3D reconstruction of tilapia. Five mass estimation models are established based on the relationship between the body length and the mass of tilapia, so as to realize the mass estimation of tilapia. The results showed that the average relative errors of the method models were 5.34%~7.25%. The coefficient of determination of the final tilapia mass estimation with manual measurement was 0.99, and the average relative error was 5.90%. The improvement over existing deep learning methods is about 1.54%. This study will provide key technical support for the non-destructive measurement of tilapia, which is of great significance to the information management of aquaculture, the assessment of fish growth condition, and baiting control.

Water entry locomotion strategy for a stranding bionic robotic fish

AbstractSimilar to other underwater robots, bionic robotic fish face entrapment risks when stranded due to wave action or water level drop. In this paper, we propose a locomotion strategy for a whale shark‐inspired robotic fish, enabling it to autonomously return to aquatic environments after being stranded on land. This strategy is informed by the terrestrial locomotion capabilities of mudskippers and is particularly significant given the considerable mass of such robotic fish, which compounds the difficulty of land‐based movement. First, we introduce a lightweight YOLOv5 model‐based algorithm for deep‐water area recognition, which identifies the direction for the bionic robot fish to re‐enter the water. Subsequently, pectoral fin‐based crawling gaits are designed by the innate two degrees of freedom within the existing pectoral fin structure of the robot. These gaits empower the robotic fish to move on a multitude of terrestrial terrains. Extended field experiments have validated the effectiveness of our water recognition algorithm and locomotion strategy, confirming the ability of the whale shark‐inspired robotic fish to perform successful water entry maneuvers from the shore. Additionally, the capability to traverse various landforms are also verified. This work provides valuable insights into self‐rescue mechanisms for stranding underwater robots and promotes practical applications of bionic robotics.

A mini-review on fish mass kills within the Egyptian fisheries and aquaculture sectors: Impacts and proposed solutions

A mini-review on fish mass kills within the Egyptian fisheries and aquaculture sectors: Impacts and proposed solutions

Delayed action leads to faster turning of fish by interaction with neighbor

Schooling fish exhibit captivating biological behaviors that have garnered interest from both biologists and engineers. While the undulatory motion of fish in schools has been extensively studied, rapid turning within these schools remains underexplored. This paper presents a three-dimensional computational fluid dynamics (CFD) model of a fast-start scenario involving two fish to investigate the influence of spatial and phase differences on swimming performance. Our findings indicate that, by leveraging the wake of the upstream fish, a downstream fish can enhance its travel distance by up to 34.4% and its rotational angle by up to 41.6%. The optimal travel distance is achieved when the starting jet of the front fish aligns with the center of mass (COM) of the downstream fish. Conversely, the largest rotational angle is observed when this jet precedes the center of mass. The research further identifies a vortex phase matching phenomenon in fish schools during rapid turns. The phase difference, or the downstream fish's delayed response, allows it to harness the wake for improved transitional and rotational movement. However, this approach might decrease the average angular velocity, which represents the rotational angle divided by the total duration of turning and waiting. Our study concludes that, with a specific phase difference, this delayed action facilitates faster fish turns by utilizing the wake created by the neighboring fish.

Russian per capita consumption of fish products in raw mass or marketable product weight: how to recalculate back and forth

Aim. Find a simple way to transfer the average per capita consumption of fish products (kg/person/year) from the raw mass to the mass of marketable products and vice versa.Methods. Statistical processing of official data on the consumption of fish products in the USSR and the Russian Federation, published by Rosstat (Russian Federal State Statistics Service) and FAO (Food and Agriculture Organization of the United Nations) for 58 years, was made using the least squares method.Results. Two-parameter equations are found that best describe the relationship between the average per capita consumption of fish products in the mass of raw fish and in the mass of commercial products ready for consumption, as well as coefficients for simplified approximate quick calculations of the mass of consumed raw fish by the mass of commercial products and the mass of consumed commercial products by mass of raw fish.Novelty. Based on the results of the original analysis of the material, a new method for recalculating the Russian per capita consumption of fish products in the mass of raw fish by the mass of consumed commercial products and vice versa was obtained for the first time.Practical significance. Restoration of long-term series of consumption and targets for food security, the efficiency of the functioning of the fishery complex, and the social policy of the state. The article may be useful to economists, marketers, sociologists, medicals, businessmen, officials and politicians.

Efektivitas Perubahan Fase Material KCl/H2O sebagai Sistem Pendingin Ikan Laut

This study aims to determine the effectiveness of phase change material (PCM) KCl/H2Oas a fish cooling system. KCl/H2Ois a eutectic PCM of hydrate salts with a melting temperature of -10.7 °Cand an enthalpy of 273 kJ/kg. The samples tested were Kuwe marine fish with a mass of 1 kg (4 heads). The variation in fish mass to KCl/H2Ois 1:0.5, 1:1, 1:2, and 1:3. The process of changing the temperature of the fish cooling system every time is measured using the DS18B20 temperature sensor. Based on the study's results, KCl/H2Ois effective in reducing fish temperature by -0.22 °C/minute.The use of 2 kg KCl/H2O is effective in maintaining fish temperature in the temperature range of0 to 5 °C for 20 hours, and the use of 3 kg KCl/H2Ois good in maintaining fish temperature in the lower temperature range of -5 to 0 °C for 16 hours. In terms of economy, the cost of handling the fish cooling process using KCl/H2Ois six times greater than conventional cooling, so this system is less recommended.

Breeding of whitefish Coregonus Lavaretus L. at the Knyazhegubsky fish hatchery

The article describes whitefish Coregonus lavaretus L., 1758 (Baltic environmental type) breeding results at the Knyazhegubsky fish hatchery (Murmansk region, Russia). Since 2017, the major goal of this fish hatchery has been the breeding of freshwater type of whitefish. Technology for whitefish breeding was tested in 2018-2019. A number of problems encountered by fish breeders were identified. Live fertilized Baltic whitefish eggs at the “eye pigmentation” phase are purchased every year from OOO “Forvat” fish farm (Sosnovo settlement, Priozersky district, Leningrad region, Russia) and transported to the Knyazhegubsky fish hatchery. Major fish-farming activities subsequently performed at the fish hatchery include: eggs incubation in Weiss machines, summer and winter rearing of juveniles in rearing facilities, in trout ditches, and at equipped summer site as well as release of young whitefish aged under one year into the Kovdozerskoe water reservoir. The average mass of a single young fish in the first batch released in 2019 was 0.5 grams. Juvenile fish is available for release on a partial basis into water bodies of the Murmansk region for fish-stocking purposes under contracts with business entities. Currently, technology is being worked on for rearing and formation of the breeding stock. In general, the results of the work performed indicate that Baltic whitefish (freshwater type) rearing conditions at the Knyazhegubsky fish hatchery are favorable.

Towards ecological friendly pond aquaculture in the Ili River basin (Kazakhstan, Central Asia)

Aquaculture in Kazakhstan is today in a stage of rapid development. There are a large number of ponds in the Ili River basin, but aquaculture in most of them is carried out using routine methods. The problem is aggravated by the fact that for many rare representatives of the native fish fauna, ponds are one of the last refuges. This article presents the results of a study of fish diversity in 18 pond farms during the period 2007- 2023. The results obtained showed the possibility of long-term coexistence of carp and such valuable commercial native fish species as the Balkhash marinka Schizothorax argentatus, the Ili marinka Schizothorax pseudaksaiensis and the Balkhash perch Perca schrenkii. Rearing predatory fish such as pike perch and snakehead in ponds is not only unprofitable, but also causes significant harm to the ecosystems of water bodies. On the contrary, the cultivation of pond farms in the basins of this region together with Balkhash marina carp, Ili marina and Balkhash perch not only allows for the preservation of these valuable native species and increases the mass of marketable fish, but also significantly relieves the nutrient loading on natural water bodies.