Organs Of Fish Research Articles

Analyses of Heavy Metals Bioaccumulation in the Organs of Clarias gariepinus Following Exposure to Sub-Lethal Concentrations of Waste Burnt Tire Residues

This study evaluated the bioaccumulation of certain heavy metals of waste burnt tire residues (WBTRs) in certain organs (viz-gills, liver, kidney and muscles) of Clarias gariepinus following exposure to sublethal concentrations (SLCs) of water-soluble fractions (WSFs) of WBTRs. Clarias gariepinus (average weight of 47.95±0.34g and length of 15.54±0.36cm) were exposed to SLCs at different concentrations (0.00, 0.23, 0.47, 0.94, 1.87, and3.74 ppm) of WSFs of WBTRs for a period of fifty-eight days. Heavy metal concentrations in WBTRs and in the organs of the experimental fish were measured using a handheld X-Ray Fluorescence Analyzer (NitonXL3T). Results showed that strontium, lead, zinc, cobalt, bismuth, rubidium, gold, tungsten, iron, thorium, arsenic, copper, and niobium were detected in WBTRs although the maximum level of zinc was perceived however, no significant difference (P>0.05) was observed as compared to the control group regarding heavy metal accumulation in muscles, 53.10±12.78; liver, 56.30±76.96; kidney, 164.54±12.78; and gills, 241.36±146.87 of the exposed fish. The high levels of heavy metals present in WBTRs are of great concern as potential detrimentl pollutants to the aquatic ecosystem. These allochthonous inputs get into the aquatic ecosystem through sewage flow and runoffs effluents. Resident non-target communities particularly fishes from such polluted aquatic systems with WBTRs become vunerable and incriminated with attendant high levels of heavy metals that could be detrimental to human consumers.

Decellularization of fish tissues for tissue engineering and regenerative medicine applications

Abstract Decellularization is the process of obtaining acellular tissues with low immunogenic cellular components from animals or plants while maximizing the retention of the native extracellular matrix structure, mechanical integrity, and bioactivity. The decellularized tissue obtained through the tissue decellularization technique retains the structure and bioactive components of its native tissue; it not only exhibits comparatively strong mechanical properties, low immunogenicity, and good biocompatibility, but also stimulates in situ neovascularization at the implantation site and regulates the polarization process of recruited macrophages, thereby promoting the regeneration of damaged tissue. Consequently, many commercial products have been developed as promising therapeutic strategies for the treatment of different tissue defects and lesions, such as wounds, dura, bone and cartilage defects, nerve injuries, myocardial infarction, urethral strictures, corneal blindness, and other orthopaedic applications. Recently, there has been a growing interest in the decellularization of fish tissues because of the abundance of sources, less religious constraints, and risks of zoonosis transmission between mammals. In this review, we provide a complete overview of the state-of-the-art decellularization of fish tissues, including the organs and methods used to prepare acellular tissues. We enumerated common decellularized fish tissues from various fish organs, such as skin, scale, bladder, cartilage, heart, and brain, and elaborated their different processing methods and tissue engineering applications. Furthermore, we presented the perspectives of (1) the future development direction of fish tissue decellularization technology, (2) expanding the sources of decellularized tissue, and (3) innovating decellularized tissue bio-inks for 3D bioprinting to unleash the great potential of decellularized tissue in tissue engineering and regenerative medicine applications.

Role of Storage Lipids in Vertical Migrations of Beaked Redfish Sebastes mentella in the North Atlantic.

The contents of main classes of storage lipids (triacylglycerols, cholesterol esters, and waxes) in muscles and the liver of the beaked redfish Sebastes mentella were studied across the depth gradient and in different areas of the North Atlantic. Significant differences in storage lipid contents were observed between fish from different fishing horizons. The depth-dependent changes in lipids in fish tissues and organs were assumed to indicate that triacylglycerols (TAGs), cholesterol esters (CEs), and waxes are utilized as energy sources, in particular, to maintain the buoyancy during vertical migration. The results provide a basis for further investigation of the biochemical mechanisms of migration in the commercially valuable species S. mentella of the North Atlantic and other aquatic organisms with similar swimming activities.

Assessment of human health risks posed by toxic heavy metals in Tilapia fish (Oreochromis mossambicus) from the Cauvery River, India.

Heavy metal toxicity is a serious threat to human health due to its bioaccumulation, biomagnification, and persistent nature in the environment including aquatic systems. In the recent past, heavy metal contamination in the environment has occurred due to various anthropogenic sources. The concentration of potentially toxic heavy metals was determined by Atomic Absorption Spectroscopy in Tilapia (Oreochromis mossambicus), a highly farmed and consumed fish species in southern parts of India. The mean levels of Fe were found to be higher in major organs of the fish with the highest levels in liver (Mean 1554.4 ± 1708.7 mg/kg) and lowest in the muscles (Mean 130.757 ± 33.3 mg/kg). Correlation Matrix analysis revealed relationships between the occurrence of various heavy metals in different organs of fish and indicated similar origins and chemical properties. Target hazard quotient for Cd, Co, Pb, and Cr in the Liver, Co and Cr in the Gills, and Co in Muscle were > 1 for adults, which showed a significant health risk from the combined effects of these metals. The potential health risk to humans, according to the cancer risk (CR) assessment is attributed mainly to Cd and Cr levels. Overall, moderate fish consumption is advised to limit the bioaccumulation of heavy metals over prolonged exposure and associated health risks.

Activities of Energy and Carbohydrate Metabolism Enzymes in Rainbow Trout Оncorhynchus mykiss Walb. upon Introduction of 24-hour Lighting in Aquaculture in Southern Russia.

Activities of energy and carbohydrate metabolism enzymes (cytochrome c oxidase (COX), pyruvate kinase (PK), glucose 6-phosphate dehydrogenase (G6PD), glycerol 1-phosphate dehydrogenase (G1PDH), lactate dehydrogenase (LDH), and aldolase) were studied in rainbow trout Oncorhynchus mykiss Walb. fish grown in aquaculture in North Ossetia-Alania after introducing a regime with 24-h lighting and night feeding. COX and PK activities in the liver of fish from the experimental group were found to be significantly higher than in control fish, indicating an increase in aerobic ATP synthesis. Aldolase activity in organs of fish grown with 24-h lighting was lower than in the control fish, indicating a decrease in carbohydrate utilization in glycolysis in muscles and a lower intensity of gluconeogenesis in the liver. The differences made it possible to assume that the introduction of 24-h lighting and night feeding changed energy and carbohydrate metabolism to facilitate biosynthetic processes and, therefore, weight gain in fish.

Water Quality Impact on Fish Behavior: A Review From an Aquaculture Perspective

ABSTRACTChanges in water quality significantly shape fish behavior, a crucial index reflecting the growth and welfare status of fish. Given the centrality of this relationship to aquaculture practices, a comprehensive understanding of how water quality dynamics influence fish behavior is imperative. While there have been some summaries of the effects of water quality parameters on fish physiology and growth, few reviews on their effects on fish behavior have been reported yet. This article reviews several water quality parameters which are of great concern in aquaculture from multiple facets of actual production, including physical parameters (water temperature and turbidity), chemical parameters (dissolved oxygen, salinity, pH, and inorganic nitrogen), and chemical pollutants (microplastics and crude oil), which have gained increasing attention from the researchers and aquaculture practitioners over the past decades. Variations in these water quality parameters can exert profound effects on fish physiology, metabolism, internal tissues and organs, and sensory perception, which influences fish behaviors such as swimming, schooling, feeding, predation, anti‐predation, aggression, courtship, as well as adaptive and stress‐related behaviors such as exploration, avoidance response, and anxiety‐like behavior. By synthesizing the behavioral changes caused by specific water quality parameters, this review aims to provide strong support for further water quality‐related research, thereby fostering environments conducive to both fish welfare and aquaculture productivity.

Fish guts possess higher priority in assessing ecological risk of microplastics in both fish bodies and aquatic environments

Microplastics (MPs, ＜5mm in size) have rapidly spread across aquatic ecosystems, which urgently needs systematic assessment for their ecological risk. Fish species have frequently been selected as indicator organisms in evaluating MPs contaminants. However, it has been questioned that which organs of fishes should be examined due to tissue-specific results. In this study, we investigated the accumulation and depuration process of MPs in the main organs of zebrafish under different MPs concentrations as well as the presence and absence of food resources. Our results recorded consistently higher MPs accumulation in fish guts among different MPs concentrations, implying fish guts as stable organs representing organisms’ MPs contaminants. Meanwhile, MPs accumulated in fish guts increased significantly with increasing exposure concentrations, highlighting fish guts as sensitive organs in reflecting MPs contamination in aquatic environments. In addition, MPs accumulated in fish guts under non-feeding conditions followed a logistic “S” curve while fluctuated under feeding conditions, suggesting increased ecological MPs risk with the absence of food resources. The depuration rate in fish guts was significantly higher in the feeding group than in the non-feeding group, implying better expelling ability of MPs with the presence of food resources. Our study proposes fish guts as the optimal indicator organs in assessing the ecological risk of MPs contaminants in both fish bodies and aquatic environments, and highlights the importance of sustaining sufficient food resources in aquatic environments to reduce the MPs triggered adverse effects on fish species.

Компоненты сыворотки крови как индикатор состояния растительноядных рыб

The results of studies of total protein and its fractions, as well as aminotransferases of blood serum of pond herbivorous fish are presented. Studies allow us to assess the activity of aminotransferases (alanine and aspartate aminotransferases), the activity of which in the blood serum somehow characterizes the condition and /or degree of damage to some organs of fish. Seasonal and age dynamics, as well as sex differences of the studied parameters in fish, have been established. Sex differences in these indicators are most noticeable in fish aged 0+ to 2 years. The data obtained allow us to judge the specific protein status, which differs in species characteristics and variability depending on the habitat conditions of fish, which gives an idea of the level of the physiological state of fish when grown in modern fish farms, and also allows us to assess the quality of the environment surrounding fish.

Assessment of heavy metal concentration in pelagic fish species and associated health risks along the Kanyakumari coast, India – a baseline study

ABSTRACT This research examines heavy metal concentration in fish from the Kanyakumari coast of India, emphasising its ecological consequences and possible health hazards for consumers. The study investigates the levels of several heavy metals such as zinc, manganese, iron, cadmium, copper, chromium, cobalt, lead, and nickel in different organs of multiple pelagic fish species obtained from the Kanyakumari fish landing site. Concentrations of heavy metals exhibit considerable variation among different fish organs and species, with distinct patterns identified for each metal. Muscle tissue often demonstrates reduced amounts of heavy metals in comparison to other organs. Except Zn and Fe, other heavy metals in fish muscle were above the acceptable limits set by health organisations. Cadmium was found to be 36-fold higher than the permissible limit, followed by nickel (30.4) and lead (7.6). Copper, nickel, and cadmium provide possible health hazards according to the Target Hazard Quotient (THQ). Lead and cadmium exhibit Excessive Lifetime Cancer Risk (ELCR) markedly above tolerable thresholds. Large predatory fish, such as Thunnus thynnus, exhibit elevated levels of contaminants such as cadmium. Environmental conditions, aquatic habitat, and dietary intake affect metal build-up in fish. The research employs multiple analytical methods and statistical methods, such as Atomic Absorption Spectrophotometry, correlation and Principal Component Analysis, to evaluate heavy metal concentrations and their interrelations. The study underscores the critical necessity for monitoring and mitigation techniques to combat heavy metal pollution in coastal waters and its possible effects on human health through fish intake.

Histological Based Environmental Monitoring of the Lower Nun River: Using the Histo-morphometry of Kidney, Gills, Liver, and Testes of Coptodon zillii

It is an ecotoxicological study aimed at using chemical and bio-monitoring methods to pollution status of the Lower Nun River (LNR) basin using the histo-morphometry of the Liver, Kidney, Gills, and the Testes of Coptodon zillii. Based on literature review on the environmental burdens of the LNR, the following Target Chemicals (TC) were chosen for the study: Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni) and Lead (Pb). The study involved the sampling of water, sediment and feral fish from two stations along the LNR, Peremabiri (PER) and Igbomotoru(IGB) – Experimental sites.Water and sediment samples were analyzed to ascertain the physico-chemical concentrations of potential contaminants, while the harvest fish organs of liver, kidney, gills and testes were subjected to histological study to ascertain the exposure effect. Control fishes were harvested from African Aqua-culture Centre (ARAC) – Reference Site. Analyzed sediment and water values were used to evaluate Environmental Water Quality Index (EWQI) and sediment quality, while the fish organs were analyzes and used for pollution certification and stratification. Study results showed that EWQI of PER was poor (41.9); sediment quality showed that Cr, CU and Pb were above the Maximum Allowable Toxicant Concentration (MATC) for fresh water body. Fish from IGB showed worse lesion prevalence and organ histopathologic Index (Iorg) when compared to PER, with ARAC having the best outcome. The environmental pollution status (EPS) LNR was normal at PER and was slightly polluted at IGB. The study gave credence to the use of histology as a biomarker to assess sublethal effects of environmental stressors, and in determination of the pollution status.

Specific amino acid changes correlate with pathogenic flavobacteria.

Flavobacterium is a genus of microorganisms living in a variety of hosts and habitats across the globe. Some species are found in fish organs, and only a few, such as Flavobacteriumpsychrophilum and Flavobacterium columnare, cause severe disease and losses in fish farms. The evolution of flavobacteria that are pathogenic to fish is unknown, and the protein changes accountable for the selection of their colonization to fish have yet to be determined. A phylogenetic tree was constructed with the complete genomic sequences of 208 species of the Flavobacterium genus using 861 softcore genes. This phylogenetic analysis revealed clade CII comprising nine species, including five pathogenic species, and containing the most species that colonize fish. Thirteen specific amino acid changes were found to be conserved across 11 proteins within the CII clade compared with other clades, and these proteins were enriched in functions related to replication, recombination, and repair. Several of these proteins are known to be involved in pathogenicity and fitness adaptation in other bacteria. Some of the observed amino acid changes can be explained by preferential selection for certain codons and tRNA frequency. These results could help explain how species belonging to the CII clade adapt to fish environments.

Evolution of novel sensory organs in fish with legs

How do animals evolve new traits? Sea robins are fish that possess specialized leg-like appendages used to "walk" along the sea floor. Here, we show that legs are bona fide sense organs that localize buried prey. Legs are covered in sensory papillae that receive dense innervation from touch-sensitive neurons, express non-canonical epithelial taste receptors, and mediate chemical sensitivity that drives predatory digging behavior. A combination of developmental analyses, crosses between species with and without papillae, and interspecies comparisons of sea robins from around the world demonstrate that papillae represent a key evolutionary innovation associated with behavioral niche expansion on the sea floor. These discoveries provide unique insight into how molecular-, cellular-, and tissue-scale adaptations integrate to produce novel organismic traits and behavior.

Assessing the risk of consuming fish from Kanyakumari (Tamil Nadu), India: An evaluative study on bioaccumulated heavy metals in different fish species using inductively coupled plasma mass spectrometry

Environmental pollutants which are developing an alarming situation in the contemporary world captured attention in the present research. When it comes to food safety and security concerns it becomes an important field to be studied rigorously as food contributes majorly to human and animal health. The pollution of aquatic ecosystems by heavy metals (HMs) ultimately results in adverse effect on the food chain, which is covered in the current study. Fish is considered to be one of the main components of a balanced diet plate due to its high-quality protein, which sets it apart from other dietary sources. On the other hand, it is also susceptible to the absorption and bioaccumulation of HMs at toxic levels. In our study, we have considered three different species (Nemipterus japonicus, Oreochromis mossambicus, and Lates calcarifer) of fish collected from Kanyakumari, Tamil Nadu (India). Three organs namely liver, gill, and muscle were taken into consideration for the HM profiling using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The Arsenic (As), Cadmium (Cd), Chromium (Cr), Mercury (Hg) and Lead (Pb) were found to be in varied concentrations ranging from 0.1 to 1.13, 0.89–1.45, 9.95–30.66, 0.14–1.62, and 24.69–189.5 µg/kg respectively, in the studied organs of fish. Carcinogenic and noncarcinogenic risk assessments were also done indicating a notable level of Pb and Cr in selected fish species. The Hazard Index (HI) for Oreochromis mossambicus was >1 for adults and children, indicating future possibility of probable health hazards on daily consumption of these fish. In Oreochromis mossambicus, the cancer risk (CR) values for Cr and As were significantly high, particularly for children, indicating a possible occurrence of acute health risk as it exceeded the threshold of 1 × 10−3 and suggesting a significant concern. Though consumption of fish on daily basis in such significant quantity is practically impossible both for adult and children, rendering these species safe.

Antagonistic effects of Bacillus subtilis-derived chitosan nanoparticles on growth performance, stress biomarkers, and histological alterations of cadmium-intoxicated Nile tilapia fingerlings

Heavy metals including cadmium (Cd) are one of the major persistent and non-biodegradable wastewater pollutants. However, Cd reaches the aquatic ecosystem via industrial and agricultural waste discharges and causes serious deterioration in the welfare status of aquatic animals. The use of feed supplements with immune-stimulants to mitigate the toxic influences of heavy metals including Cd is a much more intriguing point. Thus, the current experiment used the bio-synthetized chitosan nanoparticles derived from Bacillus subtilis (Bs-CNPs) as a feed supplement and evaluated its ameliorative impacts on the growth and welfare status of Cd-intoxicated Nile tilapia (Oreochromis niloticus). Bifactorial design (3 Bs-CNPs levels × 3 Cd levels) was used in the current study where Nile tilapia fingerlings (58–63 g) were fed on 0.0, 2, and 4 g Bs-CNPs/kg feed alongside with exposing to 0.0, 0.392, and 0.784 mg Cd/L for 60 days to represent nine treatments as follows: T1: control group (no Cd exposure; no Bs-CNPs supplement); T2 and T3: fish were intoxicated with 0.784 and 0.392 mg Cd/L, respectively; T4 and T5: fish fed on 2 and 4 g Bs-CNPs/kg feed, respectively; T6 and T7: fish were fed on 2 g Bs-CNPs/kg feed along with exposure to 0.784 and 0.392 mg Cd/L, respectively; and T8 and T9: fish were fed on 4 g Bs-CNPs/kg feed along with exposure to 0.784 and 0.392 mg Cd/L, respectively. It is noted that the Cd-intoxicated fish exhibited significant retardation in growth performance and digestive enzyme activities with a decline in their survival rate compared to the control group (T1). The results also revealed that exposing fish to Cd toxicity alone with no feed supplement (T2 and T3) experienced abnormal clinical signs and behavioral changes. Compared with the control group (no Cd with no Bs-CNPs), highest values of cortisol, glucose, aspartate and alanine aminotransferase, and acetylcholine esterase activity were found in fish fed on the control diet along with exposure to 0.784 mg Cd/L. Higher Cd restudies in liver, intestine, gills, kidney, and muscles tissues were detected in fish exposed to 0.784 mg Cd/L alone and the sequence order of Cd levels in different fish organs is intestine > gills > liver > kidney > muscles. Remarkable pathological alterations in hepatic and intestinal tissues were also observed. On the other hand, feeding Nile tilapia on Bs-CNPs-enriched diets alone with no Cd exposure enhanced their growth performance, digestive enzyme activities, and hematological parameters with no Cd residues in fish organs. Interestingly, feeding the Cd-intoxicated fish on diets with Bs-CNPs (4 g/kg feed) returned their growth, digestive enzymes, hematological, and biochemical parameters to approximate those of the control group. Furthermore, these treatments showed histopathological alteration recovery in the intestine and liver tissues is similar to those in the control group (no Cd with no Bs-CNPs). Fish fed on Bs-CNPs levels with no Cd exposure showed no Cd residues in different fish organs. The Cd levels in different organs of fish exposed to 0.392 mg Cd/L along with feeding on Bs-CNPs (4 g/kg feed) were lower than those in Cd-exposed fish treatments. Consequently, the current study evoked that feeding Nile tilapia fingerlings on Bs-CNPs (4 g/kg feed) could enhance their growth performance and protect the fish from the Cd toxicity that may occur in the aquatic ecosystem.

Various effects of feeding level on ammonia tolerance in Carassius auratus under different ammonia exposure stress and the underlying mechanisms

Elevated ammonia levels in aquaculture systems could reduce fish growth and survival rates and produce a range of physiological problems. Ammonia toxicity in aquatic environments was regulated by various factors. Feeding was usually reported to help in the detoxification of fish, thereby increasing their capacity to tolerate ammonia nitrogen. However, the impact of different feeding amounts on fish in relation to ammonia exposure stress remains to be determined. To determine how feeding levels affected fish's responses to different ammonia nitrogen concentrations, two acute toxicity experiments were conducted with Carassius auratus gibelio, the major strain of gibel carp in aquaculture systems in China. In Test I, fed Carassius auratus gibelio (3 % body weight) showed a higher survival rate under a specific ammonia exposure stress. 96-h LC50 of NH3-N to 3 %F gibel carp was 1.1 times greater than that for NF (no feeding). In Test II, all fed groups (2 %F and 4 %F) under low and high ammonia stress exhibited improved ammonia detoxification, evidenced by higher liver GSase, GDH, and glutamine concentrations compared with the NF treatment. Muscle glycogen levels in feeding treatments were higher than those in NF, indicating that fed fish have more energy for ammonia detoxification. While compared with low ammonia treatment (2.70 mg L−1 TAN; NH3 0.06 mg L−1), fish exposed to high ammonia levels (26.03 mg L−1 TAN; NH3 0.57 mg L−1) demonstrated a decrease in food consumption, severe histopathological alterations in their liver, gill, and kidney, and decreased GSase, GDH, and glutamine production in the liver and brain. The results partly supported our hypothesis and suggested that increasing feeding enhances gibel carp's tolerance to ammonia nitrogen. The highest detoxification metabolism was observed under low ammonia stress. While excessive ammonia exposure could inhibit feeding and damage the detoxification organs of fish, and thus reduce the detoxification metabolism of gibel carp.

Contrasting the distribution kinetics of microplastics and nanoplastics in medaka following exposure and depuration

Direct ingestion of micro/nanoplastics (MNPs) results in significant accumulation in gastrointestinal (GI) tract of fish. The breathing process of fish makes MNPs easily retained in their gills. However, the uptake of MNPs in other fish organs remains largely unknown, let alone their kinetic processes. Herein, microplastics (MPs) and nanoplastics (NPs) in vivo imaging and precise quantification in various tissues (GI tract, gill, liver, brain, eye, and skin) of seawater (SW)- and freshwater (FW)- acclimated medaka Oryzias melastigma were achieved at an environmentally relevant concentration. Subsequently, the distribution kinetics of MNPs was investigated over a 96-h uptake and 48-h depuration period. MNPs were quickly and mostly captured in GI tract and gill of O. melastigma, and then transferred to liver and brain likely via blood circulation. Such transport was more efficient for NPs as compared to MPs, as evidenced by the consistently higher bioconcentration factors in both SW and FW conditions. The detection of MNPs in eye and skin of O. melastigma was more of an adsorption process, although the specific mechanisms of adsorption and absorption process can hardly be clearly differentiated. This study presented distribution kinetics of MNPs in O. melastigma and highlighted their possible transportation among tissues.

Effectiveness of Tuba Root (<i>Derris elliptica</i>) on Histological Structure of Rabbit Fish Liver

Rabbit fish (Siganus vermiculatus) is one of the biological resources in the sea that is widely consumed by the people in Maluku. Rabbit fish are caught during low tide with nets or by using natural resources to poison the fish, such as tuba root (Derris elliptica), which contains rotenone to make fish easy to catch. This study aimed to determining the concentration of tuba root extract that was effective against damage to the liver tissue of rabbit fish. Rabbit fish and tuba root were collected from Oma Village, Haruku Island, Central Maluku District, Maluku Province. In the study, a laboratory experiment was conducted in which the tuba root was treated with doses of 0.1 g, 0.3 g, 0.5 g and 1 g with an exposure time of 18 to 24 hours. Data were analyzed using two-way analysis of variance (ANOVA) followed by Duncan's post-hoc test. As a result, the lowest level of liver damage in rabbit fish was observed at a dose of 0.1 g, with a total damage of 7 ± 0.00 and 8.5 ± 0.71. Conversely, the highest level of liver damage was observed at a dose of 1 g, with a total damage of 14 ± 0.00 and 15 ± 0.00. The results of the post hoc test showed a subset value of 0.1 g dose (7.75), 0.3 g dose (9.25), 0.5 g dose (12.00), and 1 g dose (14.50). This research indicates that administering tuba root to rabbit fish can result in damage to the liver's structure. The severity of this damage is contingent upon the dose administered, whereas exposure duration does not affect the level of damage to fish organs.

Identification of microplastic content in milkfish ponds in Lontar Village, Serang Regency

Microplastics measuring < 5 mm can easily enter the fish's body through the respiratory system and digestive system. The aim of this research is to calculate the abundance of microplastics and determine the types contained in the bodies of milkfish, water and sediment in the Lontar Village Pond, Serang Regency. There are 6 stations, 4 fish samples were taken from each station, water samples were taken using a plankton net and sediment samples were taken using individual pipes at each station. The number of fish samples was 24 fish, meat, intestine, stomachs and gills were taken. Fish organs were destroyed using 10% KOH. Samples were incubated for 24 hours until the organic material was destroyed. Then filtered using Whattman No 42, and dried using an oven at 60ºC for 1 hour. Likewise, filtering of water and sediment samples is carried out. The types of microplastics found were fragments, fibers and films. The highest abundance was in the gills and intestines with an abundance of 11 per individual. The highest abundance of microplastics in the water in Lontar Village ponds is the fragment type with a total of 5 per/20 mL at station 3 and the film type with a total of 5 per/20 mL at station 6 and in the milkfish pond sediments of Lontar Village the highest abundance of microplastics is 1 per/25 gr. The types of polymers found in the digestive tract of milkfish are Polycarbonate (PC), Acrylonitrile butadiene styrene (ABS), Latex, Polystyrene (PS), Nylon, and Polytetrafluoroethylene (PTFE).Keywords: Aquaculture; Lontar; Microplastics; Milkfish

Содержание железа в органах и тканях каспийского рыбца Vimba vimba persa (Pallas)

The object of research in this work is the Caspian vimba Vimba vimba persa (Pallas), one of the commercial fish species of the Caspian Sea. Fish samples taken in the middle part of the Caspian Sea in the autumn period from 2020 to 2023 were analyzed. The work includes studies of Fe concentration in organs and tissues (muscle tissue, gonads, liver, gills, gastrointestinal tract) and food coma of the Caspian vimba Vimba vimba persa (Pallas) aged 2 and 3 years old. It was revealed that Fe accumulation in the liver occurs to a greater extent in the body of the Caspian vimba, and to a lesser extent in muscle tissue. A comparative analysis of the metal concentration was carried out depending on the sex and age of the fish. It was found that females accumulate Fe to a lesser extent than males. The average concentration of Fe in the body of 2-year-old females was 184.11 mg/kg of dry matter, and in 3-year-old females 163.58 mg/kg of dry matter. The average concentration of Fe in the body of males aged 2 years was 203.39 mg/kg of dry matter, and in males aged 3 years 225.92 mg/kg of dry matter. There is also an increase in the concentra-tion of Fe in the body of males upon reaching the age of 3, and a slight decrease in concentration in females. There are sexual differences in the distribution of metal in fish organs (liver, gills, gonads). Of particular interest is the dynamics of metal in the gonads (increases in females, decreases in males). There occurs redistribution of metal in the organs and tissues of fish.

Физиологическое состояние стерляди в условиях садковых и бассейновых хозяйств

The growing conditions of sturgeon fish affect the growth and physiological state, their morphological characteristics. The study of changes in physiological processes under the influence of a complex of factors in the conditions of cage complexes and closed water supply systems will allow for timely adjustment of technology and reduce risks when growing commercial products. The repair and breeding herds of fish breeding enterprises contain sterlet individuals of different ages, which annually, upon reaching puberty, enter the fish breeding process as producers. In this regard, we have studied the main morphophysiological indicators of two-year-olds kept in cages and in closed water supply installations (CWSI). The influence of environmental factors was noted not only on growth indicators, but also on the size of the internal organs of fish and their condition. The unstable temperature regime in the cages, dependence on unpredictable changes in the hydrochemical parameters of the aquatic environment contributes to deep physiological transformations of an adaptive nature, which slows down the growth rate and accumulation of reserve substances. Changes in morphometric parameters were also evident. In sturgeon, there is an increase in the relative weight of the heart, spleen and gonads, a decrease in the weight of the kidneys and liver. The influence of optimal temperature and trophic conditions on the index of the gastrointestinal tract was noted, which was slightly lower in fish from the CWSI than in individuals exposed to negative factors in cages. Sterlet blood counts, regardless of the conditions of detention, corresponded to physiologically healthy individuals. The creation of optimal hydrological and trophic conditions in CWSI contribute to the accumulation of phospholipids and linolenic fatty acids in tissues, which play an important role in the adaptation of the body to negative environmental factors.