فصلنامه محیط زیست جانوری
سال هفدهم شماره 1 (بهار 1404)

In this study, the habitat suitability of wild goats has been modeled in Hermod protected area with 208,731 hectares extent. This area, located in southern Zagros Mountains between Fars and Hormozgan provinces with a hot and dry climate, suffered severe droughts and a gradual decrease of habitats quality as a result in recent years. wild goat is a large-sized species and play a key role in the middle of the mountainous ecosystem’s food chain in Iran. In addition to controlling the balance of herbaceous species, this species plays an important role in the diet of large predators such as leopards and wolves. Two main goals of the present study were to identify the habitat prefers of this species and to determine the importance and degree of influence of each of the influencing factors on the suitability of its habitat.

Using global positioning system and field visits throughout the year (From the beginning of the spring to the end of the winter of 2023), 66 presence points of wild goats were recorded as dependent variables. Environmental variables (including 18 bioclimatic variables, three topographic variables and six human variables) was also assigned as independent variables and using the Maximum entropy (MaxEnt) software habitat suitability was modeled. To create 19 bioclimatic variables derived from temperature and precipitation (Bio1-Bio19), the Biovars function was used in the dismo package in the R software. 70% of the total presence points were used for modeling (training) and 30% for model validation (test). The validity of the model was measured based on the area under the ROC curve (AUC).

The results of habitat suitability modeling showed that a total of 19021.72 hectares (9.11%) of the Hermod protected area, is suitable for wild goats. In terms of the validity of the model results, in this study, the value of AUC was 0.939, which indicates the excellent predictive performance of the model. The results of examining the importance of the factors affecting habitat suitability showed that the most important variables are elevation and slope with 37.3% and 19.3% respectively.

The results of the present study can help wildlife managers and policy makers to meet conservation and management goals and reduce the conflict between wildlife and humans.

The present experiment was designed to investigate the effect of prebiotics and plant essential oils (thymol, carvacrol, and eucalyptol) on milk production performance and safety parameters of Holstein dairy cows during the transition period. 

This design was carried out in the form of completely random statistical designs with 3 treatments and 6 repetitions each. The treatments included zero levels, 10 grams and 20 grams of prebiotics and plant essences, which were forcefully fed to the cows during the evening meal.

The results showed that there was no significant difference in the immunoglobulins of goats in the first milking. Average milk production and percentage of milk protein increased significantly in the treatments of 10 and 20 grams of prebiotics and plant essential oils. But other milk compositions did not show any change. The factors related to red blood cells and white blood cells did not have significant differences in the whole period. The presence of ziralenone in the urine of cows in the treatment of 20 grams of prebiotics and plant essences had a significant difference in both sampling periods and was less than other treatments. In terms of the amount of acetic, caproic, isobutyric and isovaleric fatty acids, the group receiving prebiotics and plant essential oils had a significant increase compared to the control group. Examining the expression of interferon gamma gene showed that the treatments had no effect on this gene.

It can be concluded that the use of plant prebiotics along with plant essential oil has a positive effect on livestock production in the postpartum period, but it has no effect on the immune system of cows in this particular period.

The aim of this study is to investigate the prevalence of hip dysplasia in Persian and DSH cats at the one of the referral diagnostic imaging clinics located in Tehran. 

In this study, the data and graphs in the system were prepared and adjusted by Flat panel DR (Digital direct radiography SAMSUNG GR 40 CW) device. From the data set, about 100 Persian cats and 200 DSH cats were collected and studied. The data were statistically analyzed in terms of age, sex, race, presence or absence of unilateral or bilateral hip dysplasia, presence of arthrosis in the hip joint, occurrence or non-occurrence of constipation or severe constipation.

The present study is a large statistical survey on the prevalence of femoral hip dysplasia in Persian and DSH cats in Iran. The prevalence of this condition is 39% in Persian cats and 2% in DSH cats. According to the investigations carried out in this study, the prevalence of this complication is more bilateral than unilateral. Also, factors like age, the possibility of arthritis in the pelvic joint and the possibility of constipation have a significant relationship with this complication, while no significant relationship was found between things like gender with the said complication.

More studies should be done in this field to obtain the prevalence of femoral hip dysplasia in cats in other breeds and geographical areas.

Wound healing and the use of medicinal plants are important and vital issues. Herbal medicines, including black cumin, have been used due to their effectiveness in treating wounds and minimal side effects. Therefore, in this research, the effect of green cumin, because it is from the cumin family and is native to Iran, on the rate of healing in terms of appearance and the amount of tissue protein in skin wounds was investigated.

Twenty-five male rats were randomly divided into 5 groups of 5, negative control, placebo group (gel and no cumin extract), nitrofurazone ointment group, 10% cumin extract group and 20% cumin extract group. They were randomly divided .
After the preparation and sterile conditions, a full-thickness skin wound was created on the back of the rats. The wounds were treated for 10 days.

The results showed that in cumin groups 10 and 20%, wounds heal better and faster on the 10th day after wound formation. In terms of the amount of wound protein, the amount of tissue protein was higher in cumin groups, but there was a significant difference between the groups.

The results showed that cumin extract, unlike black cumin extract, despite the faster and better healing of wounds in terms of appearance, does not have a significant effect on the amount of skin protein.

The common pheasant (Phasianus colchicus) is widely distributed in the temperate to subtropical areas of the Palearctic region and four of its five known subspecies are present in Iran. Despite the fact that the common pheasant species is known in terms of morphology and genealogy, the habitat selection of this species in Iran remains unknown and as a result of the lack of this information as well as dangers such as excessive hunting, this species is included in the list of protected species by the Environmental Protection Agency of Iran. and this case makes it more important to identify its suitable habitats for the implementation of species protection programs.

In this research, ecological modeling was done using the maximum entropy's method (MaxEnt) to correctly predict the geographical distribution of this species in Mazandaran province. For this purpose, habitat suitability modeling was done from the recorded points of the presence of common pheasants in the north of the province in a 5-years period and fifteen habitat variables under the model of maximum entropy. Validation of the model was done using the area under the curve (AUC) and the usefulness of the variables with the analysis of the jackknife test.

According to the results, the AUC value was 0.918, which indicates good accuracy of Maximum entropy's model. Also, the modeling results showed that the variables of elevation (digital elevation model), annual precipitation, distance from forested areas and precipitation of the hottest season are the most important in predicting the presence of populations of this species in the suitable habitats of Mazandaran province. Also, the investigations showed that the distribution of pheasants in this province is mainly in the eastern and northwestern regions of the province.

The results of this research can play an important role in taking necessary measures to protect the habitat of this important species under the support of the Environmental Protection Agency in the future.

This study was conducted to investigate the effects of different levels of sumac seed powder in the diet of broiler chickens on performance, carcass characteristics, blood biochemical parameters, immunity, intestinal morphology, cecal microbial flora, fatty acid profile, and sensory taste of breast meat in broilers.

The experiment was carried out using 250 broiler chickens in a completely randomized design with 5 treatments and 5 replicates per treatment, with 10 birds per replicate. The experimental treatments included a control diet (without sumac) and diets containing 250, 500, 750, and 1000 mg/kg of sumac seed powder during the growth and finishing periods. Growth performance was measured periodically, and at the end of the 42-day period, three birds from each experimental unit were slaughtered to evaluate carcass characteristics and measure cecal intestinal morphology. Blood samples were collected from three birds per experimental unit at the end of the trial to assess blood biochemical parameters. To evaluate the immunity of broiler chickens, the relative weight percentage of immune-related glands was assessed.

The results showed that the use of different levels of sumac powder had significant effects on performance, carcass characteristics, blood parameters, immunity, intestinal morphology, cecal microbial flora, fatty acid profile, and sensory taste of breast meat (P<0.05). The findings indicated that live bird weight, feed intake, and feed conversion ratio during the starter, grower, and finisher periods were significantly influenced by treatments containing sumac powder (P<0.05). Survival rate, live meat production per square meter, and final profit were significantly improved (P<0.05). The weights of breast meat, thigh meat, abdominal fat pad, wings, and viscera were significantly affected (P<0.05). Additionally, differences in glucose concentration, triglycerides, total cholesterol, uric acid, HDL, LDL, albumin, globulin levels, and liver enzymes such as alkaline phosphatase (ALP), AST, and ALT were significant in birds receiving sumac powder (P<0.05). The height and width of villi as well as crypt depth in the small intestine were significantly altered in treatments receiving sumac powder (P<0.05). The relative weights of immune-related glands such as the bursa of Fabricius, thymus gland, and spleen were also significantly affected (P<0.05). The population of lactobacillus and Escherichia coli in the cecum was significantly influenced (P<0.05). Sensory attributes including fat content, juiciness, tenderness, flavor, color, chewability (cohesiveness), elasticity, mouthfeel perception, and overall acceptability were significantly improved (P<0.05).

In this study, the treatment containing 1000 mg/kg sumac powder had the most pronounced effects on performance parameters, blood biochemical indices, immunity status, intestinal morphology, carcass characteristics, cecal microbial flora composition, fatty acid profile, and sensory attributes of breast meat in broiler chickens.

An experiment to investigate single-cell protein replacement with soybean meal and adding probiotics to the diet, of the relative weight of internal organs (liver, pancreas, bile, spleen, and heart), and reproductive organs (Oviduct, Ovary), the number of ovarian follicles, and the pH of intestinal contents and feces were performed in laying hens aged 42 to 52 weeks.

One hundred and eighty, Leghorn Hy-line W36 white layer hens, were used in the form of a 3×3 factorial test and based on a completely randomized design with 9 treatments, 4 repetitions, and 5 birds per replication. The factors studied consisted of three levels of soybean meal replacement with single-cell protein (zero, 30, and 60 %) and three probiotic levels (zero, 50, and 100 mg/kg). The experimental period lasted 70 days, and throughout the test period, water was at libitum, and feed was provided to the birds as recommended by the catalog. At the end of the experiment, two birds from each replicate were slaughtered and the relative weight of the liver, pancreas and bile, spleen and heart, oviduct and ovary, as well as the pH of the intestine and feces and the separate count of the ovarian follicles were examined.

The relative weight of organs and internal reproduction were not affected by different factors in a single-cell diet. However, supplementing the diet with probiotics increased the weight of the gallbladder (p<0.05), spleen (p<0.04), and the marginal increase of the pancreas (p=0.08) and the marginal decrease of the liver (p=0.07). The interaction effects of single-cell protein and probiotics on the weight of reproductive organs were not significant. The addition of single-cell protein and probiotics to the diet had no effect on the weight of reproductive organs and the number of ovarian follicles in laying hens (P<0.05). Substituting 30% soybean meal with single-cell production and adding probiotics to the diet decreased the pH of ileum contents (P<0.01).

The results of the present study show that the replacement of soybean meal with single-cell protein did not show an adverse effect on the traits studied. Also, the addition of 100 mg of probiotics improves the relative weight of some internal organs (spleen and gall bladder) and reduces the pH of the ileum contents of the intestine.

This research carried out to investigate small intestine microbial flora, intestinal tissue changes and performance after feeding with tomato pomace processed with urea and an enzyme supplement to broiler chickens.

In this research, 504 broiler chicks were used in a completely randomized design with seven treatments and four replicated and 18 chicks in each unit. Experimental treatments include: tomato pomace processed without enzymes at a rate of 15 percent of the diet; tomato pomace processed with urea without enzymes (15 percent of the diet); tomato pomace processed with urea with enzymes (15 percent of the diet); tomato pomace processed without enzymes (20 percent of the diet); tomato pomace processed with the urea without enzymes (20% of the diet); and tomato pomace processed with urea with enzymes (20% of the diet). At the end of the experiment, one chicken was selected from each replicate and the samples of the ileum, jejunum, and cecal intestinal tissue were collected. pH and the number of Lactobacillus and Escherichia coli bacteria of the ileum, jejunum and histomorphometry characteristics of secum were measured.

The findings showed that the pH in all three groups fed with tomato pomace were decreased in compared to the control group (P<0.05). Villi high in groups treatment with 15% without processing and three levels of 20% without processing, processing with urea and processing with urea-enzyme showed significant difference in compared to the control group (P<0.05). None of the experimental treatments improved the feed conversion ratio as compared to the other groups.

As unlike the other treatments, there were no decreasing of chickens fed with tomato pomace processed without enzymes at a rate of 15 percent of the diet, and the number of Lactobacillus in all experimental groups were increased as compared to the control groups, it seems that the addition of 15% processed tomato pomace was suitable for the diet of broiler chickens.

Ammonia is known as a toxic substance for aquatic organisms, which can be derived from various sources, including agricultural runoff, sewage, and as a waste product from the catabolism of amino acids and proteins by aquatic organisms or resident microorganisms in water. Excessive levels of ammonia can lead to toxicity and stress. Another important issue in aquaculture is the high density of cultured fish in ponds, which itself acts as a limiting factor in the development of aquaculture and increases water ammonia and stress. The present study was conducted to investigate the effect of these two factors on the cultivation of Asian sea bass under high density in freshwater.

For this purpose, 375 pieces of Asian sea bass were randomly assigned to 5 groups with 3 replicates at densities of 6 (G1), 8 (G2), 10 (G3), 12 (G4), and 14 (G5) gr/L, and the daily ammonia concentration was measured for a period of 60 days. At the end of the cultivation period, in addition to innate immune system, and evaluation Histopathological of gills tissue were measured. In the G1, G2, and G3, following 30 days, no pathological lesions were observed in the examined gills.

However, in the G4, 50% of the samples exhibited lesions like hyperemia and bleeding, while in the G5 with the highest density, 75% of the gills showed lesions such as hyperemia and bleeding. After 60 days, the G1 and G2 remained free of any pathological lesions. Nevertheless, in the G3 and G4, 16/6% of the gills displayed lesions, and in the G5, 33/3% exhibited lesions such as hyperemia and adhesion of secondary lamellae. The results of the present study showed that complement and lysozyme activity on day 30 had a significant difference between the groups (P<0.05), so the G5 showed the highest value. Also, the highest activity of reduction Nitro blue tetrazolium (NBT) and myeloperoxidase was observed in the G1 and G3 was observed in respectively (P<0.05). However, no significant difference was observed in antitrypsin during the day. On the 60th day, a significant decrease in the amount of complement, lysozyme and antitrypsin was observed in the G5 (P<0.05), also the amount of myeloperoxidase in the G1 and the amount of NBT in the G5 had the highest amount (P<0.05). Regarding other parameters such as total protein activity, globulin and bactericidal effect, a significant difference was obtained between the groups on day 30 and 60 (P<0.05). The present study showed that the density of 12 (G4) and 14 (G5) gr/L in the first 30 days of the experiment, histopathological lesions were observed in the gill tissue, but this type of fish in the mentioned densities is in line with the conditions of increased ammonia water, on the 60th day, the reduction of lesions in the gill tissue was observed, and these responses were adjusted in line with the adaptability of the fish to the prevailing stress conditions.

According to the results of Immune system and histopathological investigations, the concentration of 8 gr/L (G2) is usually enough to ensure the healthy growth of fish during the culture period (long term) and at the same time, it prevents problems such as stress and diseases.

Mullets makes a significant part of the bony fish catch in the Caspian Sea. The entry of heavy metals in organic and inorganic forms into water resources and its bioaccumulation in edible fish is very important in terms of public health.

During fishing season of 2022-2023, 27 mullets (Chelon auratus) were prepared from the fishing area in the Caspian Sea in Guilan province in order to determine the number of heavy metals in the muscle and liver tissues using spectrophotometer ICP-OES device. The purpose of this study was to compare the number of heavy metals measured with the valid international standards of WHO, FAO, MAFF and European Union.

For arsenic, cadmium, lead, mercury, copper, zinc and iron heavy metals, the average results were measured 0.377±0.323, 0.127±0.086, 0.182±0.077, 0.125±0.075, 0.432±0.481, 2.420±2.550 and 6.870±9.170 μg/gr respectively in the muscle tissue of golden mullet. Measuring the amount of these heavy metals in the liver tissue of the examined fish and comparing it with the muscle tissue showed that in all cases, the accumulation of metals in the liver is higher.

Comparison of the heavy metal accumulation investigated with international valid standards showed that in all cases the amount of these heavy metals in the edible tissue of fish (muscle) is lower than the standard of the WHO, FAO and MAFF. In comparison with the standard of the European Union, except for two metals arsenic and cadmium, the accumulation of other heavy metals investigated in the muscles of golden mullet of the Caspian Sea was within the standard range.

Marine fish are important in providing animal protein and human health. The study of pathogenic factors of these fish, including parasitic factors, plays an important role in applying preventive policies and quality control of fishery products. Therefore, it seems necessary to identify the morphology and molecular parameters of fish parasites in the Persian Gulf, which are considered to be one of the main sources of food in Iran.

In the present study, 20 pieces of infected Sorkhu and Ghobad fish were caught and analyzed separately from the coastal areas of the Qeshm, and kish in Hormozgan province. For each fish, morphological characteristics including length and width, body weight, standard length in Sorkhu, fish and fork length in Ghobad fish were measured and recorded. Each infected fish peritoneum, viscera, and entire digestive tract of each infected fish were examined macroscopically for the presence of gastrointestinal nematodes and isolated. Then, the collected nematodes were identified after washing and storing in preservative and clarifying solutions. Nematode larvae were examined by PCR method to confirm the diagnosis by molecular method with specific primers of each genus.

18 (90%) and 20 (100%) fish pieces were infected with nematodes from Sorkhu cidentified in Scomberomorus guttatus fish were Terranova and Ascarophis, respectively. Ascarophis and Raphidoscaris species were detected as the most abundant nematodes in Lutjanus johnii; It should be mentioned that the nematode species of Ascarophis, Hystrotilacium and Paracamalanos in Scomberomorus guttatus fish and Capillaria, Eustrongyloides and Cosmoxynemoides in Lutjanus johnii fish had the lowest level of contamination. In molecular studies, larvae and parasitic nematodes suspected by PCR method with specific primers of each genus, infection of Scomberomorus guttatus and Lutjanus johnii fish with nematode species Tranova, Anisakis, Ascarophis and Hysterothylacium after sequencing and comparing the degree of similarity of their genomes with other species. Nematode was confirmed by the World Gene Bank (NCBI).

This study showed that due to the high level of nematode contamination, especially zoonotic nematodes in bony fishes of the Persian Gulf, it is important to monitor the stages of preventing the transmission of infectious parasitic agents parasites and to monitor the stages of processing and consumption of marine fish to ensure their health safety and quality.

Marine collagen, as a biomedical material, has been taken into consideration because of biodegradability, low immunogenicity, as well as being water soluble, safe, and easily-extractable. We extracted ASC (acid-soluble collagen) from Scomberomorus commerson fish skin found in Persian Gulf, Iran.

Physical and chemical characterizations using various techniques including thermo gravimetric analysis (TGA), X-ray diffraction, scanning electron microscopy (SEM), Fourier transformation infrared (FTIR), SDS-PAGE (sodium dodecyl sulphate-polyacrylamide gel electrophoresis), and MTT assay of the ASC.

Results showed that the yield of collagen was 20.30%. SEM observation revealed that the structure of the ASC was fibrils with irregular dense sheet-like structures. SDS-PAGE analysis showed that Scomberomorus commerson ASC had α (α1and α2) and β chains, presumably belonging to type I collagen. The content of amino acids and proline in ASC was 18 per 1,000 residues and 90.7 per 810.3 residues, respectively. Also, 27.06% of the ASC was composed of glycine. FTIR analysis and the spectrum X-ray diffraction demonstrated that the Scomberomorus commerson skin collagen had a triple-helix structure with the collagen denaturation temperatures of 45 °C and 291.89 ºC. Cell activity and proliferation testing demonstrated that S. commerson collagen sample promotes cell growth and proliferation and its hydrophilicity leads to cell attachment.

In conclusion, the Scomberomorus commerson fish skin can perform as an affordable collagen source for medical biomaterials and pharmaceutical applications.

In the present study, the effect of different levels of dietary supplement chitosan, zinc oxide and zinc oxide nanoparticles coated with chitosan on growth indices, survival, body chemical composition and digestive enzyme activity of Pacific white shrimp was investigated for 90 days.

For this purpose, shrimps with an average weight of 3.27 ± 0.11 g in 300-liter fiberglass tanks with a density of 40 shrimps per tank, in the form of eight different treatments with levels of 10, 20 and 40 mg/kg of dietary supplement containing zinc oxide and zinc oxide nanoparticles coated with chitosan and 36 (mg/kg) chitosan and control treatment (without additive) were fed with 3 replicates. At the end of the period, the growth indices including average body weight gain, body weight gain, specific growth ratio and food conversion ratio, survival rate, body chemical composition and digestive enzymes activity (amylase, lipase and protease) were compared with the control treatment.

The results showed that the use of different levels of zinc oxide and zinc oxide nanoparticles coated with chitosan in the diet significantly improved the growth and survival indices, so that the most appropriate increase in body weight, specific growth rate and the food conversion ratio was observed in the treatments of zinc oxide 20 and zinc oxide nanoparticles coated with chitosan 10 mg/kg (p<0.05). Regarding the biochemical analysis of the carcass and the activity of digestive enzymes, the results indicated a significant increase in the amount of protein and fat and the activity of amylase, lipase and protease enzymes in the experimental treatments compared with the control treatment (p<0.05).

The results of this study showed that the level of 10 mg/kg zinc oxide coated with chitosan in the diet could be used to improve growth performance, survival, digestive enzymes activity and carcass quality of Pacific white shrimp.

This study aimed to investigate the effects of the prebiotic supplement inulin on growth, digestive, hematological, and immune indices in juvenile Pacific white shrimp (Litopenaeus vannamei).

In this experiment, 25 shrimp with an average weight of 4.88 ± 0.03 g were randomly distributed in 12 polyethylene tanks (300 liters, 25 shrimp per tank) with aeration, and fed a commercial diet for 14 days. Different levels of inulin extracted from the root of chicory were added to the commercial diet. After the culture period, five shrimp from each tank were randomly selected for biochemical analysis.

The results showed that the treatment containing 2% inulin resulted in a higher weight gain compared to other treatments. Also, the highest specific growth rate and the lowest food conversion rate were observed in the treatment containing 2% inulin. Regarding hematological indices, the values of total hemocyte count and semi-granular cell count were significantly different in treatments containing 0.5% and 1% inulin compared to the control, but no significant difference was observed in the treatment containing 2% inulin. In terms of immune indices, the values of lysozyme and phenoloxidase enzymes were higher in treatments containing 1% and 2% inulin. Based on the results, the use of inulin as a probiotic can be effective in improving growth, hematological, and immune indices in Pacific white shrimp.

Based on the results obtained, the treatment containing 2% inulin had the best performance compared to other treatments and can be considered as the best treatment for feeding Pacific white shrimp using inulin as a prebiotic.

This study aimed to investigate the meristic characteristics and morphometric relationships of the Penaeid shrimps that were caught monthly in the Khor Khoran international wetland from December 2020 to January 2022. This study aimed to investigate the meristic characteristics and morphometric relationships of the Penaeid shrimps that were caught monthly in the Khor Khoran international wetland from December 2020 to January 2022.

Sampling was done by using nets that were used by local fishermen in the area (with a local name of jelbily and with mesh sizes of 5 mm) and a number of shrimp samples were randomly selected every month. A total of 1274 shrimps were measured biometric data bioassayed.

The meristic data results showed that in Penaeus merguiensis, the first dorsal tooth is often located after the second ventral tooth, and the distance between the first and second teeth is greater than the distance between the second and third teeth. In the Indian white shrimp, Penaeus indicus, the Anterior dorsal tooth is located after the third ventral tooth. The first dorsal tooth in Penaeus penicillatus is located before the first ventral tooth, and the distance between the first and second dorsal teeth was less than the distance between the second and third teeth. In jinga shrimp, Metapenaeus affinis, the telson had no lateral spines, and the number of dorsal teeth on the rostrum varied between 8-11. Also, this study is the first report of the presence of P. penicillatus in the southern waters of Iran.

Weight- length relationship for P. merguiensis, P. indicus, P. penicillatus and M. affinis, were calculated W=0.0065, W= 0.0077, W= 0.001 and W=0.6769, respectively.

The Persian Gulf is one of the most important water ecosystems in the world, which has faced serious environmental threats in recent years. Due to their non-biodegradability, heavy metals represent a potential danger through accumulation in aquatic tissues and impact on human health as the final consumer. Therefore, investigating the accumulation of metals in the bodies of aquatic organisms and their entry into the body of consumers is considered the first step in monitoring the health of consumers.

The present study investigated the bioaccumulation of three metals Pb, Cd, and Cr in different organs of Pampus argenteus and Lutjanus johnii caught off the shores of Bandar Lange in the north of the Persian Gulf. Subsequently, the estimated daily and weekly intakes (EDI and EWI) for children and adults were calculated, along with the permissible consumption limits (CRLim and CRmm), and the potential risk of consuming these fish in relation to non-carcinogenic diseases (THQ). For this purpose, 30 specimens of each type of fish were prepared and chemically digested according to standard protocols.

The results indicated that the highest concentration of metals was found in the liver tissue of L. johnii, whereas the lowest concentration was in the muscle tissue of P. argenteus. The trend of metal accumulation in both species followed the order: Cr> Cd > Pb, noted consistently in the liver, gill, and muscle tissues. The study also found that the concentration of metals was higher in female fish than in males for both species. The bioaccumulation factor (BAF) for all metals were higher in L. johnii than in P. argenteus, which can be attributed to the greater reliance of L. johnii on bed sediments for their nutritional needs.

A comparison of the metal concentrations in fish tissues with World Health Organization (WHO) standard suggested that the consumption of these two species does not pose a threat to consumer health. The EDI and EWI for metals in both adults and children, across both fish types, were significantly lower than the reference values. In addition, the THQ for individuals consuming these fish types is very low, indicating no significant danger to the consumers of these fishes. The results of the present study will provide a framework for wider studies on the effect of seafood consumption on the health of consumers.