Fish Samples Research Articles

Distribution and environmental preferences of Saprolegnia and Leptolegnia (Oomycota) species in fish hatcheries in Hungary

We studied for the first time the abundance and species distribution of water molds (Oomycota, Saprolegniales) in fish hatcheries in Hungary, with a focus on Saprolegnia and Leptolegnia spp. A total of 182 water mold isolates were obtained from different developmental stages of fish (eggs, fry, and adults) and water samples collected during the spawning season of cyprinids and salmonids. Of the ten water mold species identified based on their ITS–rDNA sequences, S. parasitica, S. ferax, and S. australis were the most abundant. Statistical analyses of species proportions in relation to the sample source and host preference revealed that S. parasitica was significantly more abundant in the host than in water samples, whereas the opposite trend was observed for S. ferax and S. australis. In addition, our results confirmed previous findings that S. australis and S. ferax prefer warm water (+21–24 °C) and that S. parasitica has a wide temperature tolerance (+3–24 °C). The DNA sequence identity analysis showed that the species demarcation criterion for Saprolegnia spp. was approximately 98 % identity, based on ITS–rDNA sequences. Furthermore, our phylogenetic analyses suggest that taxonomic revision of Leptolegnia spp. is necessary.

Accurate and stable detection of p-phenylenediamine antioxidants and their transformation products in aquatic products using antioxidant protection – Analysis of actual aquatic products

Given the high toxicity of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD) derivatives, such as 6PPD quinone (6PPDQ) to salmon, as well as their ubiquitous presence in the environment, the contaminant of aquatic food products has drawn significant attention. However, analytical methods for p-Phenylenediamines (PPDs) and their transformation products (TPs) in aquatic products remain underdeveloped. In particular, the degradation of some compounds and strong matrix effects complicate detection. In this study, we present a stable, rapid, and sensitive method combining salt-out assisted extraction, antioxidant protection, and multi-plug filtration clean-up (m-PFC) to detect two PPDs and five TPs in aquatic products. Crucially, the appropriate selection of antioxidants prevented the degradation of the easily oxidized target compounds. Further, the m-PFC method significantly enhanced the purification efficiency, achieving satisfactory recoveries (62.1–115 %), and method detection limits (MDLs) ranging from 0.00300 to 0.400 μg/kg. Subsequently, the method was applied to monitor PPDs and their TPs in aquatic products systematically, revealing the presence of 6PPD and N-isopropyl-N′-phenyl-1,4-phenylenediamine (IPPD) in white shrimp from aquafarms, whereas none of the seven target analytes were detected in fish and crab samples. These findings contribute to the detection of PPDs, their TPs and other unstable chemicals in aquatic products, thereby providing insights into their concentrations in these products.

Development of molecularly imprinted polymer-based dispersive micro-solid-phase extraction for the selective extraction of histamine from canned tuna fish samples prior to its determination by GC–FID

Development of molecularly imprinted polymer-based dispersive micro-solid-phase extraction for the selective extraction of histamine from canned tuna fish samples prior to its determination by GC–FID

Development of a new high performance liquid chromatography-fluorescence detection (HPLC-FL) method for the determination of biogenic amines in frozen fish sold in markets

<p class="MsoNormal" style="text-align:justify;line-height:200%"><span lang="EN-GB" style="font-size:12.0pt;line-height:200%;font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-GB;mso-fareast-language: ZH-CN">It is now possible to measure the biogenic amines histamine, tryptamine, putrescine, cadaverine, spermidine, spermine, and tyramine in an easy, accurate, and selective manner. Dansyl chloride was used to purify the analytes, and high-performance liquid chromatography with detection of fluorescence was utilized for separating them. This is a useful method for identifying and measuring biogenic amines in fish samples in a selective manner. The C18 (250 mm × 4.6 mm × 5 μm) column was used for the separation by chromatography. A mobile phase comprising acetonitrile and phosphate buffer (pH=4.0) (60:40, v/v) was used at an average flow rate of 0.9 mL/min. The technique relied on utilizing fluorescence detection to determine the derivative </span><span style="font-size:12.0pt;line-height:200%;font-family: "Times New Roman","serif"">(λ<sub>ex</sub>=230 nm, λ<sub>em</sub>= 350 nm) </span><span lang="EN-GB" style="font-size:12.0pt;line-height:200%;font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-GB;mso-fareast-language: ZH-CN">The suggested method's linearity was examined between 0.01 and 50 μg/mL </span><span style="font-size:12.0pt;line-height:200%;font-family:"Times New Roman","serif"">(r<sup>2</sup>=0.9996). </span><span lang="EN-GB" style="font-size:12.0pt;line-height:200%;font-family: "Times New Roman","serif";mso-fareast-font-family:"Times New Roman";mso-ansi-language: EN-GB;mso-fareast-language:ZH-CN">In compliance with ICH criteria, the method was verified with respect to accuracy, precision, repeatability, specifity, robustness, and detection and quantification limitations. The suggested technique has been effective in tracking the production of biogenic amines in specimens of fish that can be purchased frozen in marketplaces. It was discovered that the recommended approach worked well for routinely analyzing fish sample biogenic amine analyses.<o:p></o:p></span></p>

A classic key innovation constrains oral jaw functional diversification in fishes

Abstract Modifications to the pharyngeal jaws—a prey processing system located posterior to the mouth cavity—are widely considered a key innovation that enhanced diversification within several prominent fish clades. Seen in cichlids, damselfishes, wrasses, and a few other lineages, these musculoskeletal alterations are believed to increase the evolutionary independence and, thus, the diversification of the oral and pharyngeal jaw systems. To test this classic hypothesis, we conducted comparative phylogenetic analyses to assess the effect of the pharyngeal novelty on the diversification of feeding morphology and kinematics across a taxonomically diverse sample of spiny-rayed fishes. We quantified movements of the oral jaws and other craniofacial structures from 689 suction-feeding strikes using high-speed videos collected from 228 species with and without the pharyngeal jaw novelty. Contradicting long-held predictions, we find significantly greater disparity across all traits and faster rates of oral jaw functional evolution in fishes without the specialized prey processing system. The modified pharyngeal jaw is undoubtedly a functional innovation as it enhances the strength of the prey processing system, facilitating exceptional transition rates to feeding on hard and tough prey. However, it also restricts the diversification of the feeding system, revealing that the impact of pharyngognathy is more nuanced than previously thought. In light of these and other recent findings, a reinterpretation of the macroevolutionary consequences of the pharyngeal jaw novelty is needed.

Characterizing Juvenile Common Snook and Tarpon Habitat to Guide Conservation and Restoration of Coastal Wetlands

To conserve or restore juvenile fish habitat, resource managers, restoration practitioners, and engineers need fine-scale information to understand what conditions they need to preserve or what specifications are needed to create new habitat. The objective of this study was to develop statistical models using a dataset of 18 coastal ponds in Southwest Florida, USA, to predict the abundance of juvenile common snook Centropomus undecimalis (hereafter snook) and presence of juvenile tarpon Megalops atlanticus, both of which are flagship species used for conservation and restoration of subtropical and tropical wetlands. Model predictors included water conditions and characteristics of vegetation, sediment, and geographic position. Modeling results indicated that juvenile snook used coastal ponds that were directly connected to tidal creeks. In contrast, juvenile tarpon were more likely to be present in coastal ponds that were separated from tidal creeks by dense mangrove forest (e.g., elevation > 0.48 m above Mean Low Water) characterized by highly organic sediment and low dissolved oxygen, to which tarpon are well adapted. Overlap between snook abundance and tarpon presence was greatest where connections between ponds and the nearest tidal creek were at a relatively low elevation (e.g., -0.12 m relative to Mean Low Water). Although these findings are most applicable to management and conservation of populations in areas along the Gulf coast of Florida (i.e., in areas of similar tidal range and coastal geomorphology), incorporating more detailed habitat surveys to better capture landscape context, geomorphology, and connectivity into fish sampling designs should be broadly applicable to estuarine fish ecology.

Classification of Kudoa thyrsites infected and uninfected fish using a handheld near-infrared spectrophotometer, SIMCA and PLS-DA.

Kudoa thyrsites infection of marine fish typically results in myoliquefaction, which is only apparent 24 to 56 h post-mortem. The traditional methods for the detection of K. thyrsites infected fish are time-consuming and destructive, reducing its marketability. This poses a challenge for the fish industry to remove infected fish before it reaches the market or further processing activities. This study investigated the use of near-infrared (NIR) spectroscopy, in combination with soft independent modelling of class analogy (SIMCA) and partial least square discriminant analysis (PLS-DA), for discriminating K. thyrsites infected fish from uninfected fish. Performance of the classification models was evaluated by calculating the sensitivity, specificity and precision. A total of 334 fish samples (200 sardine, 64 hake and 70 kingklip) were used for this study. Infection of K. thyrsites was determined with the use of qPCR assays. Ninety per cent (90%) of the sardine samples, 78% of the hake samples and 37% of the kingklip samples were infected. Class groups of infected and uninfected fish samples were created for the purpose of generating SIMCA and PLS-DA classification models for each species of fish, as well as for a species independent data set. Principal component analysis (PCA) of NIR spectra did not show any clustering for infected and uninfected samples. Calibration and test sample sets were generated for the purpose of building and testing the SIMCA and PLD-DA classification models. SIMCA and PLS-DA were unable to classify test samples correctly into the two classes. The number of misclassifications (NMC) was higher for the SIMCA models than for the PLS-DA models, with more than 60% incorrectly classified. SIMCA classified most of the test samples into both classes. The precision for PLS-DA were 89% for sardine, 81% for hake, 0% for kingklip and 87% for species independent models, however, most samples were classified at infected. The use of NIR spectroscopy and classification models such as SIMCA and PLS-DA showed limited use as a method to distinguish between K. thyrsites infected and uninfected fish samples. Textural and chemical changes during extended frozen storage of the fish samples may have masked the effects associated with K. thyrsites infection. Further studies are suggested where NIR spectroscopy is used in combination with texture analysis and image spectroscopy.

Microplastic Pollution in the Marine Ecosystem: A Study of Seawater and Fish Samples from Bhaucha Dhakka and Versova Beach, Mumbai Coast

The prevalence of microplastics in our environment is well recognized, but the deep extent of its impact on ecosystems is unknown. This study investigates the prevalence of microplastics in seawater and three species (Bombay duck, Silver Pomfret, and Indian prawn) of commercially available marine fish from the Mumbai suburbs. The investigation found microplastics in both water and fish samples, with an average concentration of 20 ± 14.8 MPs/L and 42 ± 14.8 MPs/L in two water samples from Versova Beach and Bhaucha Dhakka selected for the study. And 70 ± 10, 36 ± 08, and 23 ± 09 MPs/L respectively in three fish species. The highest concentrations were found in water samples from Bhaucha Dhakka and Bombay duck (Harpadon nehereus) from Bhaucha dhakka. The discovery of microplastics in fish tissues raises concerns about their potentially harmful impact on fish health and the implications for human consumption.

Evaluation of Praziquantel effectiveness in treating Nile tilapia clinostomid infections and its relationships to fish health and water quality

This study aimed to conduct a multidisciplinary investigation integrating detailed morphology, molecular characterization, water parameters, histopathology alteration, and the trials of treatment of Clinostomum spp. In this study, 300 Nile tilapia (Oreochromis niloticus) were collected from the farmed and wild Nile River at Al Bahr Al Aazam, Giza Governorate to assess Clinostomid infection prevalence. Fish and water samples were collected from private fish farms, and water drains at Dakahlia, and Giza, Egypt. Analysis of the water revealed inadequate water quality, particularly in the fish farms. Snails and piscivorous birds were abundant at fish collection sites. The recovered Clinostomid MCs morphological characteristics and COI gene sequence analysis identified them as Clinostomum complanatum, C. phalacrocoracis, and Euclinostomum heterostomum. Clinostomid MCs disturbed the fish’s hematological and biochemical blood parameters. Bath treatment of parasitized fish with praziquantel (2 mg/L for 24 h) revealed a significant reduction in the number of vital MCs vs. infected fish (non-treated). Praziquantel (PZQ) is an effective and safe therapy for controlling Clinostomid infections affecting farmed Nile tilapia. The current findings indicate a link between poor environmental conditions and Clinostomum infections in tilapia. The study highlights the impacts of Clinostomid MCs on fish health and recommends bath treatment with PZQ as an efficient control method for these dangerous parasites to protect human and fish health.

Infestation of isopod Norileca indica in big-eye scad Selar crumenopthalmus off Panay Gulf, Philippines

The big-eye scad Selar crumenopthalmus is a commercially important fish species in the Philippines and is not exempted from parasite infestation. Thus, study aims to determine the prevalence and intensity of isopod infestation in fish, percentage reduction of respiratory surface area of gill filaments and condition factor of the fish. A total of 274 fish samples (mean FL 142 ± 5.88 mm) were collected and examined from Panay Gulf, Philippines. The prevalence and mean intensity of isopod, Norileca indica is 9.49 % and two isopods per fish (mean FL 142 ± 5.88mm), respectively. In fish samples with infestation in both pair of gills, the percentage reduction in gill area decreases in line with increasing fish length. However, there is no significant difference between the reductions of gill area of uninfested and infested fish (p > 0.05). Moreover, there was also no clear trend and no significant difference in the condition factors of infested and uninfested fish (p > 0.05). Presence of the parasite may hinder in the food intake of fish and may prevent supply of blood to other parts of fish body which may led to stunted growth of host fish. However, fishes infested with parasite were not significantly considered as less healthy as cause of the infestation of isopod without considering other factors that would affect the fish overall state. Highlights In fishes infested with male isopod on one side and female isopod counterpart on the opposite side showed that the percentage reduction in gill area decreases in line with increasing fish length Isopod infestation in fish is not highly correlated with poor health condition of the host fish. There is no significant difference in the percent gill surface area reduction and condition factor of Norelica indica infested and uninfested fish.

Prevalence of Ectoparasites in Tilapia (Oreochromis niloticus) in Sidoarjo, Indonesia

The problem most often encountered in fish farming is disease which can cause a decrease in fish production levels. Parasites cause one of the infectious diseases found in fish farming. The presence of parasites can cause a decrease in the quality of the growth of fish production. The purpose of this study was to identify the prevalence of ectoparasites on Nile tilapia in Sidoarjo, Indonesia. Ninety-six samples from two ponds were examined under the microscope to find out the presence of ectoparasite that exists in the outside body part of the fish. Samples were collected from skin, fins, tail, and gills using native methods and observed under a microscope in the Division of Parasitology Laboratory, Faculty of Veterinary Medicine, Universitas Airlangga. The results of this study showed 86 samples positively infected by ectoparasite and 10 showed negative. The ectoparasites found in this study were Trichodina sp., Chilodonella sp., Ichthyophthirius multifillis, Gyrodactylus sp., and Dactylogyrus sp. The highest prevalence is Trichodina sp. and Dactylogyrus sp. The number of fish infested by ectoparasite is 89.56%, this is classified in the usual category. The highest prevalence occurs in infestations of Trichodina sp. i.e.72.91% which were contained in the 70 samples. While the lowest prevalence was in Gyrodactylus sp. by 8.32% in 8 fish samples. Double infections from two different ponds were 70% within 33 samples which were included in the usual category.

Improving the Quality and Safety of Fish Products with Edible Coatings Incorporating Piscicolin CM22 from a Psychrotolerant Carnobacterium maltaromaticum Strain.

The consumption of raw or smoked fish entails significant microbiological risks, including contamination by pathogens such as Listeria monocytogenes, which can cause severe foodborne illnesses. This study explores the preservative use of piscicolin CM22, a novel bacteriocin derived from the psychrotolerant strain Carnobacterium maltaromaticum CM22, in two types of edible coatings (EC): chitosan-based and fish gelatin-based. An initial in vitro characterization of the technological and antimicrobial properties of these ECs with and without bacteriocin was conducted. The efficacy of the edible coatings was subsequently evaluated through shelf life and challenge tests against L. monocytogenes in raw and smoked fish products. The results demonstrated significant antimicrobial activity, with the chitosan-based coating containing piscicolin CM22 being the most effective in reducing microbial counts and maintaining pH and color stability. Furthermore, in the challenge test studies, both ECs effectively controlled L. monocytogenes, showing significant reductions in bacterial counts compared to the controls in fresh tuna, salmon, and smoked salmon. The ECs containing piscicolin CM22 reduced Listeria counts by up to 4 log CFU/g in raw and smoked fish samples, with effective control in smoked salmon for up to 15 days at refrigeration temperature. While further research is required to fully assess their preservation potential, these findings strongly indicate that piscicolin CM22-functionalized edible coatings hold significant potential for improving the quality and safety of fish products.

Accumulation of Heavy Metals in Tissues of Oreochromis Mossambicus from the uMgeni River and Human Health Risk Assessment

Metal enrichment in aquatic ecosystems has compromised the potential of fish to enhance food security. The uMgeni River drains urban and industrialized catchment and flows through economically disadvantaged rural communities that opt for fish to supplement their protein needs. However, there are uncertainties on the safety of consuming fish from the uMgeni River. The present study aims to explore metal distribution between the water, sediment, and tissues of the preferred Oreochromis mossambicus, and evaluate whether concentrations in the muscle are safe for human consumption. The water, sediment, and fish samples were collected from Inanda and Nagle dams, and metal concentrations were analysed using inductively coupled plasma mass spectrometry. Alkaline pH was observed at both dams and metals were below detectable level in the water column. Even though metal concentrations in the water column were below detectable levels, significant concentrations were found in the sediment. No consistent trend in metal concentrations was observed across tissues, but higher levels were generally found in the liver, followed by the gill, and then the muscle. Nickel (Ni) and lead (Pb) exhibited concentrations exceeding the permissible limit for human consumption. Similarly, the target hazard quotient exceeded the threshold of 1 for Pb, chromium (Cr), and antimony (Sb) at both dams with Inanda Dam showing higher indices for Sb and Pb. The carcinogenic risk for the three metals was also found to be higher than 10–6. These findings suggest that consumption of O. mossambicus from the uMgeni River should be limited to no more than 150 g per week.

Assessment of biochemical biomarkers and environmental stress indicators in some freshwater fish

The mechanism by which an organism can adapt to subtle environmental changes is predicated on modifications to biochemical processes within the cellular metabolism in response to such changes. Changes in these processes have the potential to induce alterations in cellular structures and tissue organization, as well as establish a causal link between fluctuations in these parameters and stressors exposure. This investigation's main goal and innovation is to evaluate the environmental stress indicators in the aquatic ecosystem of Lake Qarun. Pesticide residues in freshwater fish should be the primary focus of evaluation of environmental stressor concentrations, since they serve as bioindicators at different times and places on a spatiotemporal scale. A thorough analysis of suggestive biochemical biomarker reactions should also be conducted. The effects of environmental stressors, specifically pesticide contamination in Qarun Lake, have been observed and investigated in relation to two fish species: Solea aejabtiaca and Oreochronis niloticus. The results of a hazard assessment conducted at six sampling sites using spatio-temporal data revealed elevated mean values for the pesticides, persistent organic pollutants (POPs), organochlorines, organophosphates, and pyrethroids that were detected. A multi biomarker approach facilitates a more comprehensive understanding of stress responses induced by exposure to pollutants. As a result, the activities of the biochemical biomarkers CYP-450, GST, GSH, and LDH in the blood and liver of fish samples were found to be notably elevated. The suitability of the identified variables for biomonitoring of aquatic pollution was validated, and the data unveiled variations in sensitivity among species, implying that Nile tilapia could potentially function as a bioindicator with high sensitivity. The findings were correlated with the concentrations of detrimental organochlorines, organophosphorus, and pyrethroids in the muscles and gills. The data indicates that pollutants linked to agricultural wastes, runoff, and municipal effluent may be discharged into the lake ecosystem. Consequently, to safeguard the environment, it is essential to enforce and implement policies, acts, and regulations that already exist. Assessing the effects of additional environmental stressors on aquatic ecosystems is another way in which biomarker screening with an integrative approach improves our comprehension of how toxicants impact various levels of biological organization and is particularly useful in realistic environmental exposure scenarios.

Performance Evaluation of African catfish (Clarias gariepinus) Fed Diets with Varying Dietary Inclusion Levels of Christmas Melon (Laganaria breviflorus) as a Partial Replacement for Wheat Offal

This study evaluates the effects of Christmas melon (Laganaria breviflorus)-based diets on the growth and hematology of African catfish (Clarias gariepinus) after a 6 (six)-month feeding trial. A total of 240 C. gariepinus juveniles with an average weight of 10.68 g were procured from the Fisheries and Aquaculture Department Hatchery Unit for the feeding trial. After acclimating for a week (7 days) using 2.00 mm Coppens feed (45% CP) twice per day, the fish samples were randomly distributed into 12 tarpaulin tanks of 4 ft × 4 ft × 4 ft with a 200 L water holding capacity (four (4) different treatments presented in triplicate). Twenty (20) fish per tank were fed twice daily with the compounded feed with varying dietary inclusion levels of Christmas melon (0% (control), 5%, 10% and 15%). The weights and lengths of the sampled fish were measured biweekly to determine the growth performance, while hematological parameters, such as the packed cell volume, erythrocytes, hemoglobin, and leucocytes were determined midway through and at end of the feeding trial. The data collected were analyzed using ANOVA, and the results revealed the optimum growth and nutrient utilization and hematological and serum biochemical parameters of C. gariepinus in T3. The length–weight relationship results revealed that the fish exhibited an isometric growth pattern with B-values above 3 across the treatments. In conclusion, the results obtained in this study revealed that Christmas melon (L. breviflorus) could replace wheat offal by up to 10% in the diet of C. gariepinus without negative effects on the obtained optimal growth performance, hematological parameters, or serum biochemistry.

Investigation of Microplastic Contamination in the Gastrointestinal Tract of Fish: A Comparative Study of Various Freshwater Species

The aqueous environment has been reported to be seriously threatened by the pollution of microplastics (MPs), which has been confirmed in numerous studies affecting various aquatic habitats. Despite this, few investigations exist on MP contamination in fish of specific regions. Thus, the current study aims to determine MP concentrations in the fish species of the Chhota Nagpur zone of eastern India. From August to September 2023, fish samples were collected from 10 km distance between two locations of Subarnarekha and Kharkai river banks through fishermen. Microplastics were found in the gastrointestinal tract of 45 fish of 8 species out of 48 samples. Of these species, six species were secondary consumers, while the remaining two were primary consumers. The average amount of microplastics consumed by each fish (n = 48) was 3.0 ± 1.8. A total of 144 microplastics were found in collected samples of fish species. Among the analyzed sample of MPs, 69.4% were fibers, films were (22.3%), and (8.3%) were fragments. The least contaminated species was T. ilisha (0.8 ± 0.7 particles/ind.), while L. rohita had the highest microplastic contamination (4.5 ± 1.7 particles/ind.). The present study found a negative correlation of - 0.83 between MP consumption and the mean body weight of fish. Similarly, a negative correlation of - 0.5 was found between the length of fish and MP intake. Polyamide (nylon), polypropylene, polyvinyl chloride, polycarbonate, polyethylene terephthalate, and polyethylene polymers were found. The size of MPs ranged from 45-355 μm and mainly were fibers. They were also predominantly blue and black. Polyamide and polyvinyl chloride were the common MP types in every specimen. The possible sources of MPs were fishing nets, ropes, and packaging material. This investigation points to MP contamination in aquatic ecosystems and particular species. It provides advanced knowledge of MP pollution, sources, and effects on regional ecosystems and public health.

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.

Bioecology of Wild Betta Fish (Betta schalleri) of Bangka Island Waters

The Betta schalleri is a wild betta fish endemic to Bangka Island which has potential as an ornamental fish. However, the fish’s endangered conservation status is one of the problems for its conservation efforts. The aim of this study was to analyze the Betta schalleri according to its biological and ecological properties. The research method was quantitative descriptive. Parameters measured in this study included fish morphology, fish meristics, water quality and habitat characteristics. The fish samples collected was 15 Betta schalleri. Observations on the physical characteristics of the Betta schalleri were based on morphometric characters, namely: 1) Total Length (TL) (22355.59 mm); 2) Standard Length (SL) (16386.74 mm);3) Head Length (HL) (3912.51 mm); 4) Head Height (HH) (3112.72 mm); 5) and Caudal Height (CH) (4922.29 mm). The meristic characters brought about the following 1) Dorsal Fin (D.II.8); 2) Anal Fin (A.II.24-25); Ventral Fin (V.I-II.4); Pectoral Fin (P.11-12); Caudal Fin (C.13) and Linea Lateralis (LL.31-32). The betta schalleri typically live in peat water, calm and fresh water that tend to be brown in color. The aquatic plants grow in the form of Pandanus sp. and Utricularia sp. In general, Betta schalleri thrive in a pH of 4-5, a temperature from 280C to 310C, and dissolved oxygen of 5.6- 11 mg/l.

Assessment of water quality and emerging pollutants in two fish species from the mallorquin swamp in the Colombian Caribbean

The Mallorquín Swamp, an important ecosystem in Atlántico, Colombian Caribbean, underwent environmental monitoring at eight points during rainy, transition, and dry seasons. This was to assess water quality, seasonal variation, and the bioaccumulation of metals, emerging pollutants, and organic compounds in the fish Ariopsis canteri and Mugil incilis. Water parameters were analyzed using descriptive statistics and multifactorial ANOVA with the Tukey HSD test for seasonal differences. Normality and variance of the fish results were verified, and differences between groups were evaluated using ANOVA or Kruskal-Walli's method when data transformation failed. Spearman correlation was used to relate the results. Water sampling revealed variations in temperature, dissolved oxygen, salinity, and nutrient levels. Significant differences in alkalinity and hardness were observed across seasons and sample points. The most probable number (MPN) levels of Total coliform and E. coli peaked near areas with domestic wastewater inputs, reaching 5.4x106 and 4.0x106 MPN, respectively, indicating potential microbiological contamination of water. Fish samples revealed high concentrations of persistent substances such as methylmercury, polycyclic aromatic hydrocarbons (PAHs), and emerging pollutants. Heavy metal analysis showed elevated iron levels (5.28 ± 0.657 mg/L), while emerging pollutants, including ibuprofen (218 μg/L) and naproxen (343.89 μg/L), exhibited high concentrations near human settlements. Ariopsis canteri showed higher bioconcentration tendencies for methylmercury (238.5 ± 100 μg/kg), and acenaphthene (7782 ± 4123.8 μg/kg), possibly influenced by its feeding habits and habitat preferences. In contrast, Mugil incilis exhibited higher bioaccumulation trends of PAH (2376.23 ± 599.63 μg/kg acenaphthene) and emerging pollutants like galaxolide (139.49 ± 34.98 μg/kg), possibly due to its mobility and exposure to various contaminants in their environment. These findings emphasize the need to monitor and manage aquatic ecosystems' health to mitigate anthropogenic influences on water quality and biodiversity. This research serves as a reference for global conservation efforts, emphasizing the need for comprehensive monitoring and regulatory frameworks to protect aquatic environments and ensure their sustainability for future generations.

Magnetic solid-phase extraction of trace elements in water and fish using greenly synthesized MnFe2O4 @ Cabbage hydrochar/Chitosan ternary composite

A new analytical method for determining lead, cadmium, and copper in water and fish was established employing a novel synthesized magnetic eco-friendly ternary nano-composite adsorbent of manganese ferrite@cabbage hydrochar/chitosan (MnFe2O4@CBH/CTS). Cabbage leaves were employed as a green fuel, acting as a reducing and capping agent in the green manufacture of manganese-ferrite nanoparticles, and then hydrothermally carbonized to form hydrochar. The novel material underwent FT-IR, XRD, SEM, EDX, and BET investigation, revealing a micro-porous surface. The magnetic solid-phase extraction (MSPE) technique was used to enrich the samples and separate the matrix for GFAAS analysis. The impact of adsorption factors such as pH, extraction duration, metal ion concentration, and interference from coexisting ions were examined. Based on a preconcentration factor of 50, the method demonstrated LOD (3σ/m) ranging from 6-18ngL-1, linearity (ng L-1) from 48-450 (Pb), 20-180 (Cd) and 59-300 (Cu), and precision (RSD, n=3) of 1.8-3.9% (1.0μgL-1) and 3.0-4.6% (10μgL-1). The approach was effectively applied to the analysis of tested elements in water and marine fish samples, with spiked sample recoveries above 95% and an RSD of less than 5.4%.