Catfish Samples Research Articles

Occurrence, source delineation, and health hazard of polycyclic aromatic hydrocarbons in tissues of Sarotherodon melanotheron and Chrysichthys nigrodigitatus from Okulu River, Nigeria.

Polycyclic aromatic hydrocarbons (PAHs) are mistakenly consumed by people through their diet, including food and water. The occurrence, source, and health hazards of 16 PAHs in 36 tilapia (Sarotherodon melanotheron) and silver catfish (Chrysichthys nigrodigitatus) samples from Okulu River, Nigeria were investigated in this study. The total PAH concentration ranged from 11.70-24.20 to 13.40-19.60µg/kg, being statistically different between the two species. The values were higher than the European Commission limits of 12µg/kg and within the World Health Organization limit of 20µg/kg. The 16 PAHs were detected in both fish species. The diagnostic ratio revealed that petroleum, fossil fuel, and incomplete combustion of biomass wastes were the sources of PAHs in the fishes. Pearson's correlation showed that the PAHs can come from diverse sources. The non-carcinogenic risk quotients (HQs) and hazard index (HI) in both fish species were 1, an indication of no adverse health effects. Among the 9 PAHs that were used to calculate the HI, BaP and BgP accounted for 31% and 62%, respectively, for Chrysichthys nigrodigitatus, and 25% and 69%, respectively, for Sarotherodon melanotheron. The carcinogenic hazard of the 7 PAHs assessed was within the acceptable range of 10-6-10-4. But the sum of the carcinogenic hazard was on the order of 10-3 in both species of fish, an indication of carcinogenic health effects. 79% and 75% of the total carcinogenic risk for Chrysichthys nigrodigitatus and Sarotherodon melanotheron, respectively, are from DaA and InP. The consumption of PAHs by residents of the study area and other population groups through fish foods from the studied river underlines the importance of checking PAHs in aquatic foods for health concerns on a frequent basis.

EFFECTS OF GINGER (Zingiber officinale) and CLOVE (Syzygium aromaticum) EXTRACTS ON THE QUALITY OF Clarias gariepinus PROCESSED WITH KAINJI MODIFIED DRUM KILN

The research was aimed to evaluate the preservative effects of Ginger and Clove extract on the quality and shelf-life of Clarias gariepinus processed with Kainji Modified Drum Kiln. Thirty six (36) Clarias gariepinus species were obtained from Kabod Fish Farm, Jimeta-Yola. Phytochemical compositions of ginger and clove extract indicated the presence of Saponins, Flavonoids and Tannins in both Ginger and Clove, while Glycosides, Steroids and Trepenoids were only detected in Cloves. The Catfish samples were immersed in the aqueous solution prepared (Ginger Aqueous Solution (GAS) and Clove Aqueous Solution (CAS)) separately and transferred to the Kiln for smoking. Data were analyzed using ANOVA. There was no significant difference (P>0.05) in all the fish samples treated with ginger, clove and combine (ginger and clove). The proximate composition of freshly processed and preserved C. gariepinus showed low crude protein (36.31 – 42.47 g/100g Dry matter) and crude lipid (16.65 – 24.35g/100g Dry matter) while crude protein (50.80– 56.87 g/100g Dry matter) and crude lipid decreases (14.98 – 19.00 g/100g Dry matter). The results show that the Catfish samples treated with ginger, clove and combined (ginger and clove) as preservatives prior to processing indicates the effectiveness of these preservatives in controlling yeast and mold growth and capable of inhibiting microbial growth in stored Catfish products that was processed by Kiln. The improvement and development of packaging (using low cost local packaging materials) and good storage conditions will protect the products against spoilage and breakages for more than twelve (12) weeks without any insect

Assessment of Heavy Metals in Fish Tissues of Tilapia and Catfish from River Hadejia, Northern Nigeria

Kidney failure has become a growing problem at Hadejia Emirates over the last decade. This can be attributed to water pollution, possibly due to heavy metal contamination of River Hadejia that affects organisms living in it, such as fish. This study is aimed to determine the concentration of heavy metals (As, Cd, Cr, Pb) in two fish muscles. The research was conducted on tilapia and catfish where two samples of both fishes were used. The fish tissues were cut and oven-dried at 110 °C, and then a motor and pestle were used to powder the dried fish sample. A wet digestion method was used based on the analytical methods for Atomic Absorption Spectrometry (AAS). The result obtained shows that the concentrations of heavy metals (Cr, Cd, As and Pb) in both fishes were found to be 0.3220 ± 0.0028; 0.1656 ± 0.002 (𝑚𝑔/𝑘𝑔), 0.0319 ± 0.0018; 0.0333 ± 0.0018 (𝑀𝑔/𝑘𝑔), 0.0697 ± 0.0011; 0.1035 ± 0.0015 (𝑚𝑔/𝑘𝑔) and 1.008 ± 0.0035; 0.600 ± 0.002 (𝑚𝑔/𝑘𝑔) respectively. The mean concentration value of the two samples of both tilapia and catfish were found to be above WHO standard limit except for cadmium in tilapia which is below WHO standard limit.

The bacterial flora of Oreochromis niloticus and Clarias gariepinus from earthen ponds in Sagana and Masinga, Kenya

Abstract. Karimi RD, Ngeranwa JJN, Njagi ENM, Kariuki S. 2022. The bacterial flora of Oreochromis niloticus and Clarias gariepinus from earthen ponds in Sagana and Masinga, Kenya. Intl J Bonorowo Wetlands 12: 63-73. Food-borne diseases traced to fish consumption have been reported globally, including in Kenya. The aspect of food quality as far as fish consumption is concerned is underestimated in Kenya though aquaculture has been promoted. The bacterial flora of Tilapia (Oreochromis niloticus Linnaeus, 1758) and Catfish (Clarias gariepinus Burchell, 1822) from Masinga Dam and earthen ponds at Sagana fish farm was determined in this study to determine the anti-microbial response of the pathogenic bacteria. Tilapia fish and Catfish samples were collected from Masinga Dam and Sagana farm in the dry and rainy seasons. The fish were skinned, and gut content was taken for laboratory tests. The water and water sediment samples from these two study sites were also collected. Those samples were processed and cultured in MacConkey agar, and the selective media were subcultured in the colonies and then subjected to morphological examination from cultures. Then, the biochemical tests were carried out using commercially available API kits. The study showed the presence of bacterial species belonging to Enterobacter spp. (n=34), Pseudomonas spp. (n=6), Aeromonas spp. (n=5), Vibrio spp. (n=3) and Acinetobacter spp. (n=2) isolates during the dry season, while bacterial species belonging to Enterobacter spp. (n=31), Pseudomonas spp. (n=6), Aeromonas spp. (n=4) isolates during the dry season. The anti-microbial susceptibility analysis showed that the highest resistance rates were found against Ampicillin (Amp) (61.5% of isolates), Amoxicillin (AmL) (65.9% of isolates), Tetracycline (Te) (31.8% of isolates), and Chloramphenicol (C) (27.5% of isolates) while the lowest was Nalidixic acid (Na), Cefuroxime (Cxm) and Streptomycin (S) at (4.4% of isolates) each. All isolates were sensitive to Gentamycin (Gen), Ciprofloxacin (Cip), and Cefotaxime (CTX). The presence of the above organisms, some potentially pathogenic to humans, indicates that improperly handled, undercooked, or consumed raw fish may cause disease in susceptible individuals. At the same time, some isolates’ anti-microbial resistance indicates that the use of antibiotics in aquaculture to promote growth should be studied further with a view to policy formulation.

Environmental Health Risk Analysis of Copper Exposure to Catfish Commonly Consumed By People in Ulak Jermun Village, Ogan Komering Ilir

Catfish cultivated in rivers can be contaminated by heavy metals such as copper (Cu) which come from activities around the river. Copper exposure through the consumption of catfish will be harmful to health. This research aim to analyze the public health risks due to catfish consumption in Ulak Jermun Village, Ogan Komering Ilir. The design of study was cross sectional using the Environmental Health Risk Analysis method. The research respondents were 113 people with 5 samples of catfish taken from the river where the fish were cultivated. The analysis of heavy metal copper using the Atomic Absorption Spectrophotometer (AAS) method. The results showed copper contamination in catfish with an average concentration of 1.67 mg/kg. There were no respondents with RQ value > 1 for realtime non-carcinogenic health risks, but 11 people (9.7%) of respondents with RQ value > 1 for non-carcinogenic health risks in a lifetime. Meanwhile, for realtime carcinogenic exposure 34.5% had ECR values > 10-4 and 100% of respondents had ECR values > 10-4 for carcinogenic effects in lifetime. The conclusion was the people of Ulak Jermun are at risk of experiencing carcinogenic diseases due to copper exposure with the largest percentage of people aged> 32 years, female, and weighing ≤ 57 kg.

A Comparative Study on the Haematological and Biochemical Alterations in Catfish (Clarias gariepinus) under Natural and Artificial Environments in Sokoto Metropolis, Nigeria

Aims: The study was conducted to compare the alteration in haematological and biochemical parameters in African catfish (Clarias gariepinus) under natural (river) and artificial (ponds) habitats in Sokoto metropolis, Nigeria.
 Study Design: Whole blood and serum samples harvested from each group of the catfish were used for assessment of the haematological and biochemical parameters, respectively. Data were analyzed to compare changes between the two groups of African catfishes using T-test and P < 0.05 was considered statistically significant.
 Place and Duration of Study: Catfish samples were collected over a period of four weeks from Kwalkwalawa river and commercial fish farms in Sokoto metropolis. Samples for haematological parameters were determined at the Clinical Pathology Laboratory, Veterinary Teaching Hospital, Usmanu Danfodiyo University Sokoto. The serum analyses were performed at the Chemical Pathology Laboratory, Usmanu Danfodiyo University Teaching Hospital Sokoto.
 Methodology: A total of fifty (50) whole blood samples were obtained from live African catfishes representing twenty-five (25) samples each from natural and artificial environments.
 Results: The results showed significant changes in some haematological parameters, packed cell volume (P = 0.039), haemoglobin concentration (P = 0.001), white blood cell count (P = 0.012), and differential neutrophils (P = 0.001) and lymphocytes (P = 0.001) counts between the two groups of African catfishes studied. Significant biochemical alterations in the total protein (P = 0.001), total bilirubin (P = 0.028) and direct bilirubin (P = 0.019) were observed in catfishes under natural and artificial environments.
 Conclusion: This study shows that aquaculture environment has great influence on the haematological and biochemical parameters in African catfish. These changes were more evident in catfish reared under the natural environment. Hence, the alterations in haemato-biochemical parameters were suggestive of unhealthy state or chronic stressful condition in catfish perhaps due to natural and human caused stresses.

Ectoparasite Detection Of Trichodina Sp In Dumbo Catfish (Clarias gariepinus) In Batu Kumbung Fish Seeds, Lingsar District, West Lombok Regency

The Batu Kumbung Fish Seed Center (BBI) is such an installation and is under the auspices of the Marine and Fisheries Service of West Nusa Tenggara Province, which was established in 1959, which is located in Batu Kumbung Village, Linggsar District, West Lombok Regency. The problem that is often experienced by fish farmers is the emergence of disease attacks, one of which is Trichodina sp. The purpose of this study was to detect the presence of Trichodina sp ectoparasites in catfish (Clarias gariepinus) at the Fish Seed Center (BBI) Batu Kumbung, Lingsar District, West Lombok Regency. This research is a descriptive research type with a survey study type. The research sample was taken using random sampling from five different pool plots in (BBI) Batu Kumbung, Lingsar District, West Lombok Regency. The samples of this study were 15 samples of African catfish (Clarias gariepinus). Examination of the sample using scraping and biopsy. The results of the examination showed that from 15 samples of catfish, 8 positive samples of Trichodina sp. on the gills and obtained 7 positive samples of Trichodina sp. on mucus. Trichodina sp. It has denticles on the surface of its body, its shape is round like a disc and its locomotion is cilia on the outer surface of its body

Bioaccumulation of Organophosphorus (OPs) and Carbamate (CBs) Residues in Cultured Pangas Catfish (Pangasius pangasius) and Health Risk Assessment.

In the present study, the presence of organophosphorus (OPs) and carbamates (CBs) residues in the pond water and cultured Pangas catfish (Pangasius pangasius) samples collected from Comilla and Mymensingh areas were detected and assessed for their potential health risks. A total of 100 samples from each category were analysed among which 17% of the pond water samples and 9% of the fish samples were detected contaminated with OP and CB residues. The pond water and fish samples were extracted by liquid-liquid extraction (LLE), quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction, and ultrasonic extraction, respectively, and analysed through gas chromatography tandem mass spectrometry (GC-MS/MS). Among the detected OPs, Dursban (chlorpyrifos) and dichlorvos were detected, while among CB pesticides, carbofuran and sevin (Carbaryl) were detected in fish muscle samples. The detected OP and CB residual levels were below than the maximum residue limits (MRLs). The risk assessment study indicated no potential health risks. However, the level of compliance should be maintained through proper monitoring and controlling the overuse of pesticides in agricultural fields for public health safety.

Performance Characterization of a Locally Developed Fish Smoke-Drying Kiln for Charcoal and Briquette

Performance characterization of a locally developed fish smoke-drying kiln (10 kg capacity) was conducted using charcoal and briquette as fuel materials. Samples of fresh African Catfish (Clarias gariepinus) weighing1.03±0.24 kg, charcoal of tropical hardwood (Anthonotha macophylla) and briquette produced from a combination of saw dust, rice husk, coconut husk and palm kernel shell were procured and used for the study. A completely randomized design (CRD) with three replicates was employed for this study and LSD among treatment means determined at p ≤ 0.05. Data was collected on moisture content of smoked-dried fish, smoke-drying time, drying rate, energy expended, specific fuel consumption and energy efficiency of kiln. Results showed that the energy efficiency of kiln was 97.02% and 98.45% and specific fuel consumption was 2.57 and 4.20 for charcoal and briquette, respectively. The energy expended by charcoal and briquette fuel materials were 206 MJ and 249.6 MJ, respectively. The energy expended, energy efficiency and specific fuel consumption were higher for briquette than charcoal. The use of charcoal offered higher moisture removal and drying rate for smoke-drying process than briquette but no significant difference was observed. Conversely, using briquette fuel material required almost two extra hours to smoke-dry 1kg of catfish sample compared to using charcoal. Breakeven with charcoal as main fuel material for custom hiring of the smoke-drying kiln occurs at 952 hours vis-à-vis 998 hours when briquette is used. Economically, briquette compares closely with charcoal, and could be considered a good alternative fuel material for smoke-drying of fish. Future research should conduct organoleptic assessment on fish smoked with charcoal and briquette to ascertain consumer acceptability of the final produce.

Abridged validation of charm II screening tests for the detection of veterinary drug residues in fish farmed in Cameroon

The intensification of aquaculture in Cameroon requires efficient screening methods to control veterinary drug residues in fish. This is why the charm II radio receptor technique for the detection of antimicrobial residues in aquaculture fish initiated in Belgium was transferred to Cameroon according to Commission Decision 2002/657/EC. The validation parameters included the following tests: repeatability, reproducibility and robustness in addition to the mandatory characteristics, detection capability and specificity. Selected veterinary drug-free fish samples of tilapia (Oreochromis niloticus), catfish (Clarias gariepinus), carp (Cyprinus Carpio) and kanga (Heterotis niloticus) were spiked at different target concentrations with different antimicrobials (β-lactams, tetracycline, sulfonamides, macrolides and chloramphenicol). The detection capabilities (CCβ) were at MRPL (0.3 µg/kg for chloramphenicol), or below the regulatory limits in a range of 0.25–0.5 MRL with 0% false-negative results. β-lactams (penicillin G), tetracyclines (tetracycline, chloretetracycline and oxytetracycline) and macrolides (erythromycine A) were detected at half MRL (25, 50 and 100 µg/kg respectively), while sulfonamides (sulfamethazine) was detected at 25 µg/kg (0.25 MRL). The detection capabilities (CCβ) obtained were satisfactory as the cut-off factors (Fm) were less than the mean values of blank fish readings (B) (Fm < B). Furthermore, the method was applicable since the cut-off factor was less than the positivity threshold (Fm < T). The variability of the data under repeatability and reproducibility conditions was acceptable, with a relative standard deviation less than 15%. Results were unaffected by delaying the reading time from 0 h to 24 h after the addition of scintillation fluid, with a precision below 16%. Likewise, non-target drugs were not detected even at high concentrations (100 MRL) in a cross-reactivity study. From the overall results, the performance characteristics (detection capabilities, precision, robustness and specificity) were suitable and comparable to the initial validation results, indicating that the transfer to Cameroon laboratory was valid, the method was reliable and could be used in aquaculture fish quality monitoring programs in Cameroon.

The Analysis of Genetic Variation in the Mitochondrial ND6 Gene and its Application for the Identification of Indonesian Catfish Species

Background: Catfish is a freshwater and saltwater fish type with a wide distribution throughout the Indonesian archipelago. This study was conducted to analyze Indonesian catfish’s genetic diversity and evolutionary relationships based on the mitochondrial ND6 gene. Methods: Twenty-eight catfish samples were collected from nine rivers and one ocean in seven provinces of Indonesia. The MT-ND6 gene was amplified by using a set of primers (BaungND6F and BaungND6R). The MEGA X software was used to examine the MT-ND6 sequences for genetic variation and phylogenetic relation between Indonesian catfish populations. Result: There were 167 nucleotide site variations and thirty-two amino acid variations in the MT-ND6 gene. The genetic difference among populations ranges from 0.9 to 25% and the average evolutionary divergence in the overall populations was 14%, with catfish BB and PM having the closest genetic distance, while the farthest is BF to MP and BF to MS. In conclusion, the phylogenetic tree indicated that there were four distinct catfish clades in this study: MP, MS, KR, PM, BB and KS had been grouped with Hemibagrus nemurus (Bagridae family), EM had been grouped with Mystus vittatus (Bagridae family), BSBJ had been grouped with Pangasius pangasius (Pangasiidae family) and PD and BF had been grouped with Netuma thalassina (Ariidae family).

Isolation and Identification of Bacteria found in the milt of cultured Clarias gariepinus

Bacteria identification in fish is important; hence it provides update information on emerging and existing organisms thereby enriching the gene bank on fish disease. This study investigated bacteria associated with milt in cultured samples of African catfish- Clarias gariepinus. Catfish broodstock were collected from private Fish Farm in Ogun State, Nigeria. Fish samples were taken to the Microbiology laboratory, Federal University of Agriculture, Abeokuta Ogun State for milt microbial analyses, and amplicon were taken to International Institute of Tropical Agriculture, Ibadan for molecular characterization. Bio-edit was use for importing and mining nucleotide sequences into gene bank. The results revealed that the following bacterial organisms were present in the milt of Clarias gariepinus: Aeromonas caviae, Proteus mirabilis, Serratia rubidaea, Pseudomonas mosselii, Acinetobacter soli and Klebsiella variicola. The Basic Local Alignment Search Tools revealed the percentage similarity ranging from 86- 97.04% and their accession numbers. These bacteria indicated high levels of faecal contamination in the environment. In conclusion, bacteria were found in the milt of cultured catfish and are capable of being pathogenic to humans and may increase the vertical transfer to fry during breeding and rearing stage.

Water Content Analysis and Organoleptic Test on Smoked Catfish In Pasie Pinang Village

Smoking is a method of cooking, flavoring, or preserving food, especially fish meat. The smoking of catfish in Pasie Pinang Village is still done in the traditional way. Smoking is done with coconut fiber, wood and sawdust as fuel, smoked fish is smoked with heat and the smoke from the fuel produces a distinctive taste and aroma in fish products and the color becomes golden and brownish. The purpose of this study was to determine the water content of smoked catfish in Pasie Pinang Village and to determine people's preferences for smoked catfish in Pasie Pinang Village. The panelists used in this research were 35 people consisting of students from the University of Teuku Umar. The results showed that the water content of the three smoked catfish samples varied. Organoleptic test (n=35) in terms of color, taste, aroma, texture and overall, from the three samples tested, the fanelis preferred smoked catfish in sample three. The traditional smoking of smoked fish still has a good value on consumer acceptance.

Water Content Analysis and Organoleptic Test on Smoked Catfish In Pasie Pinang Village

Smoking is a method of cooking, flavoring, or preserving food, especially fish meat. The smoking of catfish in Pasie Pinang Village is still done in the traditional way. Smoking is done with coconut fiber, wood and sawdust as fuel, smoked fish is smoked with heat and the smoke from the fuel produces a distinctive taste and aroma in fish products and the color becomes golden and brownish. The purpose of this study was to determine the water content of smoked catfish in Pasie Pinang Village and to determine people's preferences for smoked catfish in Pasie Pinang Village. The panelists used in this research were 35 people consisting of students from the University of Teuku Umar. The results showed that the water content of the three smoked catfish samples varied. Organoleptic test (n=35) in terms of color, taste, aroma, texture and overall, from the three samples tested, the fanelis preferred smoked catfish in sample three. The traditional smoking of smoked fish still has a good value on consumer acceptance.

Prescreening veterinary drug residues, heavy metal concentration, and genetic authentication in retail catfish fillets in the Northeast United States

Veterinary drug residues, heavy metals, and species authentication were performed on the demand of the regulatory agency in retail catfish fillets. A total of 362 domestic and imported catfish samples collected from various retail markets in the Northeast region of the United States were tested for the presence of chloramphenicol (CAP), malachite green/gentian violet (MG/GV), As, Cd, Pb, and Hg according to the USDA - FSIS protocols. Species identification and mislabeling were also evaluated by DNA barcoding. Results showed 94.2% of samples barcoded successfully and an overall of 11.1% mislabeling was detected. The highest mislabeling rates were estimated for Pangasius bocourti (100%) and Pangasianodon hypophthalmus (16.7%) by species and for Cambodia (45.5%) and Vietnam (19.3%) by country of origin. Eleven samples (0.8%) tested presumptive positive for CAP while MG/GV was detected in 80 samples (22.1%). A total of 49 catfish samples (13.5%) were found to have detectable levels of heavy metals. Cd was found in 44 samples (12.2%) while 4 samples had Pb (1.1%) and only one sample had a detectable level of Hg. The concentration of Pb ranged from 35 μg kg −1 to 281 μg kg −1 and varied from 10.09 μg kg −1 to 395 μg kg −1 for Cd. Our results provide basic information about the mislabeling rate and the quality of retail catfish fillets in terms of veterinary drug residues and heavy metal concentration in the Northeastern United States which suggest the necessity of a monitoring program for seafood authenticity and quality. • The overall mislabeling rate was 11.1% and was detected more among samples from Cambodia. • CAP was detected presumptively positive in 11 samples; 4 domestic and 5 imported. • MG/GV was detected presumptively positive in 80 samples; 43 domestic and 27 imported. • 44 samples had detectable level of Cd (10.09–395 μg kg −1 ; 18 domestic, 15 imported, 11 unknown). • 4 samples had detectable level of Pb (35–281 μg kg −1 ; 1 domestic, 0 imported, 3 unknown).

Storage stability of hot smoked spiced african catfish (Clarias gariepinus)

Hot Smoked Spiced Catfish (HSSC) samples prepared under optimal conditions (garlic, 7.29 g/100 ml; ginger, 7.50 g/100 ml; turmeric, 2.5 g/100 ml; soaking temperature, 38.68 °C and soaking time, 7.51 min) were stored at ambient temperature (30±2 °C) for a period of 20 days to evaluate storage stability; un-spiced hot smoked catfish served as control. Moisture Content (MC), Thiobarbutric Acid (TBA), Peroxide Value (PV), Free Fatty Acid (FFA), Total Viable Counts (TVC) and Mould Counts (MoC) were monitored at two-day intervals as a measure of the storage stability indices. Sensory attributes of the Optimized Hot Smoked Spiced Catfish (OHSSC), control (unspiced) and commercial hot-smoked catfish were determined using a preference test. The storage stability indices values for HSSC were in the range of 6.64 - 7.01% (MC), 4.50 - 13.77 mg MDA/kg (TBA), 0.20 - 2.84 mEq/kg (PV), 0.72 - 9.64% (FFA), 9.50 - 57.00 cfu/g (TVC), 8.00 - 34.50 cfu/g (MoC). The control sample values were in the range of 6.97 - 7.30% (MC), 5.51 - 14.92 mg MDA/kg (TBA), 0.23 to 2.86 mEq/kg (PV), 2.24 - 11.88% (FFA), 13.50 - 113.00 cfu/g (TVC), and 10.00 - 49.00 cfu/g(MoC). The sensory evaluation indicated that OHSSC was most preferred in all the evaluated sensory parameters. This study established the synergistic effects of garlic and turmeric on the keeping quality and sensory attributes of hot-smoked catfish with the prospect of reducing post harvest losses.

Evaluation of Heavy Metals Concentration in Selected Seafood in Ogoni Land

Periwinkle, clam, mudskipper, shrimp and catfish are favoured seafood in Ogoni Land. The quantitative estimation of heavy metals in these favoured seafood from Kaa and Kono Rivers have not really been established. This study was undertaken to evaluate the concentration of chromium, iron, lead and cadmium in the aforementioned seafood. Fresh, clean samples of periwinkle, clam, mudskipper, shrimp and catfish were collected from fishermen at landing beaches of Kaa and Kono Rivers. These samples were transported to the chemistry laboratory of Kenule Beeson Saro-Wiwa Polytechnic where digestion was done. Quantitative estimation of heavy metals was done using atomic absorption spectrophotometer at corporate analytical service limited. Analysis showed that all heavy metals in periwinkle are greater than normal guidelines, with the exception of Fe from both rivers and Cr from Kaa. Cr is higher than the normal standards for clam in both rivers, but all others were lower. Except for Fe, all heavy metals in mudskipper exceed acceptable limits for both rivers. For shrimp, Cr and Pb levels are greater than recommended in both rivers, whereas Fe and Cd levels are lower. Cr was not detected in catfish, however Pb and Cd levels are greater than recommended for both rivers, whereas Fe levels are lower. According to a one-time evaluation, periwinkle, clam, mudskipper, shrimp and catfish from Kaa and Kono Rivers have heavy metal concentrations higher than recommended levels for safety. To minimize heavy metal bioaccumulation, these samples should not be consumed for long periods of time. Serial analysis over a long period of time should be carried out in order to provide a more definitive statement concerning the consumption of these seafood.

Rapid detection of Edwardsiella ictaluri in yellow catfish (Pelteobagrus fulvidraco) by real-time RPA and RPA-LFD

Yellow catfish (Pelteobagrus fulvidraco) is an important freshwater cultured fish in China. Enteric septicemia of catfish (ESC) and red-head disease (RHD), caused by Edwardsiella ictaluri, result in huge economic losses to yellow catfish farming industry. Rapid and handy detection of E. ictaluri is a pressing demand for diagnosis. In this study, we developed rapid, convenient, sensitive and accurate detection methods RPA (recombinase polymerase amplification), real-time RPA (based on real-time fluorescent detection) and RPA-LFD (combining RPA with lateral flow dipsticks (LFD)), targeting the conserved sequence of serC gene in E. ictaluri. The RPA-LFD and real-time RPA methods could achieve detection within 30 min at 38 °C. All the three methods had high analytical sensitivity (102 copies/μl) and were 10 times more sensitive than that in general PCR. They were highly specific for identification of E. ictaluri. 24 samples of yellow catfish from farm were examined through RPA, real-time RPA and RPA-LFD methods, the results showed the consistency with the general PCR detection. In short, RPA, real-time RPA and RPA-LFD methods characterize rapid, simple, sensitive and accurate detection and demonstrate great potential for diagnosis of E. ictaluri disease in fish farms.

Microbial Flora of Smoke-Dried Catfish (Clarias Gariepinus) Processed and Sold in Some Abattoirs in Bayelsa and Rivers States

The microflora of smoked catfish (Clarias gariepinus) sold in some abattoirs in Bayelsa and Rivers States were investigated. Smoked catfish samples were purchased within abattoirs and aseptically transported in ice-packed coolers to the laboratory. The total heterotrophic bacteria, total coliform, total hydrocarbon utilizing bacteria, total fungi and hydrocarbon utilizing fungal counts and identification of isolates from samples were analyzed using standard microbiological methods. Mean values of counts obtained showed that total heterotrophic bacteria ranged from 5.4 × 106CFU/g to 4.0 × 105CFU/g, total hydrocarbon utilizing bacteria ranged from 1.5 × 104 to 1.0 × 103CFU/g, total coliform ranged from 1.7 × 106CFU/g to 0, total fungi ranged from 4.3 × 104 CFU/g to 1.2 × 104CFU/g and total hydrocarbon utilizing fungi ranged from 3.5 × 103CFU/g to 1.1 × 103CFU/g. Kruskal Walis H test showed no significant differences (P≤0.05) in the total heterotrophic bacterial load nor in the total fungal load in the locations. Bacteria identified are Bacillus sp, Enterobacter sp, Escherichia coli, Micrococcus sp, Pseudomonas sp, Salmonella sp., and Shigella species. Bacillus sp, Pseudomonas sp and Micrococcus sp., were isolated in all the samples. Salmonella sp and Shigella sp occurred in Igbogene and Swale samples. Bacillus sp recorded the highest occurrence (34%) while Enterobacter sp. and Micrococcus sp recorded the least (7%). Bacteria with hydrocarbon utilizing potentials with percentage occurrence were Bacillus sp (70%) and Pseudomonas sp (30%). Fungi isolated were Aspergillus niger, A. flavus, Aspergillus fumigatus, Penicillium sp, Fusarium sp., and Rhizopus sp. Aspergillus species recorded the highest frequency (36.0%) while Rhizopus sp recorded the least (9.83%). Aspergillus niger, Fusarium sp and Penicillium sp were isolated from all the samples. Penicillium sp recorded hydrocarbon utilizing the potential and the highest percentage of occurrence (35.89%). The presence of a high microbial load of pathogenic bacteria and known mycotoxin producing fungi in the smoke-dried catfish are of great public health significance.

Chemical and microbial properties of kiln-smoked catfish in selected locations in Ilorin Metropolis, Nigeria

The use of smoking kiln for drying catfish is on the increase in Nigeria due to its effectiveness in reducing moisture and contamination with toxic compounds during smoking. Chemical properties of kiln-smoked catfish in selected locations in Ilorin metropolis were determined in this study. Kiln-smoked catfish were obtained from four major locations (Oyun, Asa-Dam, Tanke and Agbo-Oba) in Ilorin, Nigeria. The samples were subjected to chemical and polycyclic hydrocarbon content analyses. Dried catfish from all the locations had low moisture and crude fibre contents. There were no significant differences (p&gt;0.05) in the crude fibre contents of the kiln-smoked catfish. Protein contents ranging from 53.72-56.49% were obtained for the kilnsmoked catfish samples. Fat contents ranged from 9.92-11.77% while the carbohydrate contents ranged from 19.02-23.59%. Potassium was the most abundant mineral in the samples with no traces of lead and cadmium. Agbo-Oba samples contained the highest pyrene (2983.215 ng/ml) and total polycyclic hydrocarbon (PAHs) (3349.090 ng/ml). Data on steroid fractions indicated that 17b-estradiol was significantly greater in quantity than those recorded from other steroid fractions. Microbial analyses of the samples revealed the presence of the following pathogenic organisms: Klebsiella spp, Salmonella spp, Shigella spp, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Vibrio spp, Aspergillus niger, penicilium spp, Trichoderma spp which are harmful to man. The use of smoking kiln method improved the nutrients and reduced PAHs in catfish.&#x0D; Keywords: Smoking kiln, Catfish, Chemical properties, Polycyclic hydrocarbon, Mineral elements