Effects In Fish Species Research Articles

A comparative study of acquisition of heavy metals and its toxicological effects in fish species: Siluriformes and Channa punctata

The heavy metals damage fish's physiologic and chemical composition, causing structural damage and hindering their activities. Lucknow's fisheries sector, accounting for 1% of GDP, faces contamination from heavy metals, pesticides, and fertilizers. This study examines heavy metal levels in Siluriformes and Channa punctata fish and their buildup in the Gomati River water reservoir. Fish samples from the Gomati River near Lucknow, India, were collected and dissected into pieces with stainless steel blades. The samples were then dried at 100°C for 24 hours, revealing the anatomical features of Siluriformes and Channa punctata species. The Pb, a heavy metal, was found to have the highest concentration in the scales of Siluriformes, with values in various regions, while Cd had the lowest concentration, ranging from 0.016 to 0.112 mg/kg. Excessive consumption of fish can be dangerous due to toxic metallic elements accumulation. Siluriformes and Channa punctata fish species have high levels of Lead and Cadmium, respectively, indicating potential health risks. Channa punctata and Siluriformes fish have higher heavy metal concentrations than Siluriformes, with lead, iron, and nickel levels beyond WHO limits, while chromium, zinc, cadmium, and copper levels are below WHO limits.

Anaesthetic profile of thymol and menthol in zebrafish larvae model

Aquaculture procedures such as capturing, handling, and transporting fish can lead to stress in animals. For this reason, anaesthesia has been recommended to reduce fish stress during these procedures. Synthetic and natural anaesthetics such as tricaine methanesulfonate (MS-222) and eugenol (monoterpene) are commonly used; however, biochemical changes and aversive effects have been reported. Other monoterpene compounds such as thymol and menthol, have shown potential anaesthetic effects in fish species. Thus, further investigation of its anaesthetic properties seems imperative, and the use of the zebrafish in the early stages of its development is an appropriate model due to its advantages. Therefore, the aimed to evaluate the anaesthetic profile of thymol and menthol in zebrafish at 72 hpf (hours post fertilisation). Following the determination of the effective anaesthetic concentration, three concentrations (100, 200 and 300 mg/L for thymol and 200, 400 and 500 mg/L for menthol) were further tested by focusing on mortality rate, heart rate, behaviour features of induction and oxidative effects in comparison to MS-222 and eugenol. Both monoterpenes caused anaesthetic effects in a concentration-dependent manner, with concentrations of 200 mg/L exhibiting a similar profile to MS-222 and eugenol, as evidenced by the increased recovery times.Furthermore, anaesthesia with thymol and menthol caused post-anaesthesia motor pattern abnormalities, which supported some indicators of stress. Slight modifications in physiological parameters and antioxidant changes were observed, but their association with thymol and menthol anaesthesia is unclear. Although supporting its anaesthetic use, more extensive research will be required to fully understand the impact of these natural anaesthetics on fish behaviour and stress levels, ultimately leading to safer and more successful anaesthetic operations in the future.

Developmental exposure to sertraline impaired zebrafish behavioral and neurochemical profiles.

The number of people suffering from mental health problems is rising, with anxiety and depression now the most commonly diagnosed psychiatric conditions. Selective serotonin reuptake inhibitors (SSRIs) are one of the most prescribed pharmaceuticals to treat these conditions, which has led to their common detection in many aquatic ecosystems. As the monoaminergic system shows a high degree of structural conservation across diverse animal phyla, a reasonable assumption is that the environmental levels of SSRIs in surface water can lead to adverse effects on fish and other aquatic wildlife. For instance, Sertraline (SER), a widely prescribed SSRI, has been shown to induce adverse effects in fish, albeit most of the reports used exposure concentrations exceeding those occurring in natural environments. Therefore, there is still a great lack of knowledge regarding SERs effects in fish species, especially during early life stages. This study describes the evaluation of developmental exposure of zebrafish (Danio rerio) to environmentally relevant concentrations of SER (from 0.01 to 10μg/L), using a battery of key survival behaviors and further relating them with the expression of genes and neurochemical profiles of the monoaminergic system. We found that developmental exposure to SER did not affect embryo morphogenesis and growth. However, concentrations as low as 0.1μg/L induced hypolocomotion and delayed learning. The observed behavioral impairment was associated with augmented serotonin levels rather than other neurochemicals and molecular markers, highlighting the relationship between serotonin signaling and behavior in zebrafish.

Disruption of Neurotransmission, Membrane Potential, and Mitochondrial Calcium in the Brain and Spinal Cord of Nile Tilapia Elicited by Microcystis aeruginosa Extract: an Uncommon Consequence of the Eutrophication Process

Microcystins (MCs) are produced during the growth and proliferation of some species of cyanobacteria, mainly Microcystis aeruginosa, which has massive growth in eutrophic water bodies. Microcystins are highly toxic metabolites derived from some cyanobacteria species that exert its main effect in the liver through the inhibition of protein phosphatase (PP1 and PP2A). However, other damages in fish species are less documented and could be unexpected. The aim of the current study was to evaluate the effects of Microcystis aeruginosa extract (MaE) into the central nervous system (CNS) of the Nile tilapia. The MaE was normalized by MCs content (MC-LR). We include a positive control for protein phosphatase inhibition, norcantharidin intraperitoneally dosed at sublethal levels. On the eighth day, measurement of neurotransmission biomarkers (AChE, BChE, CbE, and GABA) were measured, as well as levels of mitochondrial calcium and the mitochondrial membrane potential by flow cytometry in the brain and spinal cord were assessed, in addition to the PP1/PP2A activity in the liver. The MCs elicited mortality at 5 µg/L. The positive control and MCs at sublethal levels inhibited the PP1/PP2A activity in the liver and induced alterations in the neurotoxicity biomarkers evaluated in the CNS. This response is probably due to the disruption of transport ions, dependent and independent of ATP because of alterations in the mitochondrial membrane potential and mitochondrial calcium. The findings of this study suggest that pollutants capable of inducing cyanobacterial blooms are able, in an indirect way, to exert neurotoxic effects in fish species through MC levels.

Residue depletion and histopathological alterations in gilthead sea bream (Sparus aurata) after oral administration of oxytetracycline

ABSTRACT Aquaculture is a key component of the animal food industry, but intensive farming conditions increase the incidence of infectious diseases. Oxytetracycline (OTC) plays a major role for infectious diseases in fishes. Its MRLs include their 4-epimers, so in this trial, the depletion of residues of OTC and 4-epioxytetracycline in muscle and liver have been evaluated in gilthead sea bream (Sparus aurata) after oral administration. Hepatotoxicity has been investigated with histopathological effects on target tissues. A validated DAD-HPLC with SPE extraction has been applied. Residual levels in muscle and liver depleted with a similar k el, but mean retention time and t ½ß resulted longer in muscle than in liver because of different vascularization. The OTC concentrations were below the LMR at 48 h after dosing. No analytical peaks ascribable to 4-epi-OTC or other derivatives were detected, while histopathology of liver showed degenerated parenchymal hepatocytes, nuclear pyknosis, focal necrosis and inflammatory leucocytes infiltration. It can be concluded that the assessment of pharmacokinetic and residual depletion of antibiotics result fundamental to determine the most suitable therapeutic regime and to minimize the toxic effects in fish species.

Bifenthrin exposure causes hyperactivity in early larval stages of an endangered fish species at concentrations that occur during their hatching season

Bifenthrin is a pyrethroid insecticide commonly used in agricultural and urban sectors, and is found in watersheds worldwide. As a sodium channel blocker, at sublethal concentrations it causes off-target effects, including disruption of calcium signaling and neuronal growth. At the whole organism level, sublethal concentrations of bifenthrin cause behavioral effects in fish species, raising concerns about the neurotoxic properties of the compound on fish populations. Here we describe the application of a high-throughput behavioral system to evaluate contaminant impacts on the sensitive early-life stages of Delta smelt (Hypomesus transpacificus), a critically endangered teleost species endemic to the San Francisco Bay Delta (SFBD), California, USA.Leveraging the natural behavior of early-larval Delta smelt, whereby they increase movement in bright light and decrease movement in the dark, we developed a test using a cycle of light and dark periods in a closed chamber to test hyper- or hypoactivity for this species. We show that early-larval Delta smelt have a significant preference to move toward light, and utilized the behavioral test to evaluate the impact of exposure to bifenthrin at concentrations found in habitats where Delta smelt reportedly spawn, ranging up to concentrations detected in tributaries to these habitats. All tested concentrations of bifenthrin (nominal 2, 10, or 100 ng/L) caused hyperactivity, over a 96 h exposure, with noted significance determined during the light period of the test. To further understand the impact of bifenthrin exposure, expression of a suite of genes relevant to neurodevelopment, the mechanistic target of rapamycin (mTOR) signaling pathway, and biotransformation in exposed larvae were also measured. Following exposure to picomolar concentrations of bifenthrin, expression of genes in the mTOR signaling and neurogenesis pathways were altered alongside behavior. This study demonstrates how light and dark cycle behavioral tests can be used to assess sensitive alterations in swimming activity in Delta smelt at early developmental stages and how gene expression can complement these assays. This approach can be used to assess the impact of multiple compounds that occur within the restricted habitat of Delta smelt, thus having the potential to greatly inform conservation management strategies for this critically sensitive life stage.

Oxidative stress and histopathologic biomarkers of exposure to bisphenol-A in the freshwater fish, Ctenopharyngodon idella

ABSTRACT Bisphenol-A (BPA) belongs to the family of endocrine disrupting chemicals (EDCs) and it is used in the production of polycarbonate plastic and epoxy resins. The reproductive toxicity of BPA is well documented but it also exerts its toxic effects through multiple pathways especially by inducing a state of oxidative stress and causing damage to the vital organs. In the present study, histopathologic and oxidative damage caused by BPA in liver and kidneys of fresh water cyprinid, Ctenopharyngodon idella was evaluated. LC50 of BPA for Ctenopharyngodon idella was determined by probit regression analysis. Fish were exposed to a sublethal concentration of BPA i.e. 3.2 ppm (1/2 LC50) for 14 days. Histologic studies revealed that BPA caused degenerative changes in liver and kidneys and exposure of sublethal concentration of BPA caused oxidative damage in both organs. Lipid peroxidation significantly increased in liver and kidneys of treated group. Catalase activity and reduced glutathione content significantly decreased in the group exposed to BPA compared to control and glutathione-S-transferase activity increased significantly in both organs exposed to the sublethal concentration of BPA. From this study it is concluded that BPA caused toxic effects in fish species by changing oxidative balance and damaging the vital organs.

Biochemical effects of pollutant exposure in fish from urban creeks in Greenville, SC (USA).

The city of Greenville, SC is a rapidly expanding urban area located on the Reedy River in the upstate of South Carolina. Historical and current point-source pollutants and runoff from impermeable surfaces have resulted in a contaminated river environment, which through previous studies was demonstrated to be reflected in biological effects in fish species in the river. Because it was not known how much smaller tributaries in the urbanized area were contributing to the pollution of the main stem of the Reedy River, we collected fish (bluehead chub (Nocomis leptocephalus), creek chub (Semotilus atromaculatus), bluegill (Lepomis macrochirus), and redbreast sunfish (Lepomis auritus)) from five smaller urban creeks in the Greenville area and measured several biomarkers of exposure in these animals. Enzymatic activities of cytochrome P450-1A (CYP1A) and glutathione S-transferase (GST) were measured, and bile samples were analyzed for fluorescence caused by polynuclear aromatic hydrocarbons (PAHs) and for excreted estrogenic compounds. The results show that some creeks triggered significant biomarker responses in collected fish, while others were relatively clean. In particular, PAHs appear to be prevalent and caused biochemical effects, while estrogenic compounds were not significantly increased in the bile of fish from these urban creeks. A striking observation was the difference in enzyme activities in chub species compared to sunfish species; sunfish had up to five times higher CYP1A activities than chubs, while the chubs had significantly higher GST activity than sunfish. These species differences should be taken into account when they are incorporated in environmental risk assessment and biological effect monitoring programs.

Organic pollution of the Büyük Menderes River, Turkey and effects on aquaculture

Water quality was measured at eight stations on the Buyuk Menderes River in Turkey (Adıgüzel dam, Yenice regülator, Sarayköy bridge, Feslek regülator, Yenipazar bridge, Aydın bridge, Koçarlı bridge, Söke regülator) between 2000 and 2013 in February, April, June, August, October and December. The resulting data were evaluated in terms of biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), ammoniac-nitrogen (NH3-N), nitrite-nitrogen (NO2-N), nitrate-nitrogen (NO3-N) and orthophosphate (o-PO4) aquaculture. According to the analysis, while river water pollution generally varied during each year, samples from certain measurement points demonstrated high pollution levels throughout the year. In this study, water parameters were classified according to the "Turkish water pollution control regulation." The studied parameters are also compared with TS 266 and WHO guidelines. While levels at Sarayköy station were generally higher than other stations, values at Adıgüzel dam were the lowest, giving it the best water quality of the eight stations. The highest values on a yearly basis were obtained in 2007 due to the severe drought in the Menderes basin within which irrigation water levels fell to 4255m(3)/ha. The BOD, COD levels are the lowest in 2009 and highest in 2007; the DO level is lowest in 2007 and highest in 2009; NH3-N, NO2-N, and NO3-N parameters are the lowest in 2007 and highest in 2009; and the o-PO4 are at the lowest level in 2004 and seen as the highest in 2007. Analysis of the data was performed by SPSS 21 statistics program. One direction ANOVA was applied to the data, which were also subject to Tukey multiple comparison tests. Differences between groups were evaluated at p < 0.05. Box-plot graphs were used to demonstrate the data distribution. In the study, it was analyzed, the effect of fish species and pollution involved in the Büyük Menderes River so far on fish species.

Tissue concentrations as the dose metric to assess potential toxic effects of metals in field-collected fish: Copper and cadmium.

The present study examined the available literature linking whole-body tissue concentrations with toxic effects in fish species for copper and cadmium. The variability in effect concentration for both copper and cadmium among species occurred within an order of magnitude for all responses, whereas the range for lethal toxicity based on water exposure spanned approximately 4 to 5 orders of magnitude. Fish tissue concentrations causing adverse effects were just above background concentrations, occurring between 1 μg/g and 10 μg/g for copper and 0.1 μg/g to 4 μg/g for cadmium. The results also show that salmonids are especially sensitive to cadmium, which appears to be a function of chemical potency. No studies were found that indicated adverse effects without increases in whole-body concentration of these metals. This narrow range for dose-response implies that a toxicological spillover point occurs when the detoxification capacity of various tissues within the animal are exceeded, and this likely occurs at a similar whole-body concentration for all naïvely exposed fish species. Elevated whole-body concentrations in fish from the field may be indicative of possible acclimation to metals that may or may not result in effects for target species. Acclimation concentrations may be useful in that they signal excessive metal concentrations in water, sediment, or prey species for a given site and indicate likely toxic effects for species unable to acclimate to excess metal exposure. Using tissue residues as the dose metric for these metals provides another line of evidence for assessing impaired ecosystems and greater confidence that hazard concentrations are protective for all fish species.

Toxic effects of pure anatoxin-a on biomarkers of rainbow trout, Oncorhynchus mykiss

Anatoxin-a is a neurotoxin produced by various bloom-forming cyanobacteria. Although it shows widespread occurrence and is highly toxic to rodents, its mechanisms of action and biotransformation, and effects in fish species are still poorly understood. The main aim of this study was, thus, to investigate sub-lethal effects of anatoxin-a on selected biochemical markers in rainbow trout fry in order to get information about the mechanisms of toxicity and biotransformation of this toxin in fish. Trout fry were administered sub-lethal doses of anatoxin-a (0.08–0.31 μg g−1) intraperitoneally. Livers and muscle tissue were collected 72 h later for quantification of key enzyme activities as biochemical markers. Enzymes assessed in muscle tissues were related to cholinergic transmission (acetylcholinesterase [AChE]), energy metabolism (lactate dehydrogenase [LDH] and NADP+-dependent isocitrate dehydrogenase [IDH]). Enzymes assessed in the liver were involved in biotransformation (ethoxyresorufin-O-deethylase [EROD] and glutathione S-transferases [GST]). The results indicated a significant increasing trend for AChE activity with the dose of anatoxin-a, possibly representing an attempt to cope with overstimulation of muscle activity by the toxin, which competes with acetylcholine for nicotinic receptors binding. Anatoxin-a was also found to significantly induce the activities of liver EROD and GST, indicating the involvement of phase I and II biotransformation in its detoxification. Likewise, lactate dehydrogenase activity recorded in fry muscle increased significantly with the dose of anatoxin-a, suggesting an induction of the anaerobic pathway of energy production to deal with toxic stress induced by the exposure. Altogether, the results suggest that under continued exposure in the wild fish may experience motor difficulties, possibly becoming vulnerable to predators, and be at increased metabolic demand to cope with energetic requirements imposed by anatoxin-a biotransformation mechanisms.

Identification and characterisation of headspace volatiles of fish miso, a Japanese fish meat based fermented paste, with special emphasis on effect of fish species and meat washing

The present study investigated the suitability of four species of trash fishes for the production of fish miso, a Japanese fermented fish meat paste compared with soy and rice miso from the point of view of product aroma. The effect of washing fish meat on finished product was also evaluated. Headspace volatiles for different miso samples were analyzed by using solid phase microextraction (SPME) technique. A total of 107 volatile compounds have been identified, where 94 were common for all the miso samples. Considering the lower threshold perception and higher odour active values 2-methylbutanal, 3-methylbutanal, methional, isoamyl acetate, dimethyl disulfide, dimethyl trisulfide, 2,3-butanedione, 3-methylethyl butanoate, 3-methyl-1-butanol, ethyl hexanoate, 1-octen-3-ol, heptanol, heptanal and 2-undecanone were identified as key compounds for the miso products. Principal components analysis (PCA) and hierarchical cluster analysis (HCA) of headspace volatiles clearly elucidated the relationship amongst different miso samples based on fish species and effect of fresh water washing of meat on aroma of finished product.