Catfish Samples Research Articles

Comparative Study of the Nutritive and Elemental Composition of Smoked and Raw Clarias gariepinus from Three Selected Fish Farms in Ado Ekiti, Ekiti State, Nigeria

Clarias gariepinus is of economic importance in aquaculture due to its rapid growth, omnivorous diet, and potential as food source. It has been widely cultured and dispensed both in raw and smoked forms in various regions to meet the demand for fish protein This study assessed and compared the nutritional quality and elemental composition of smoked and raw samples of Clarias gariepinus. A total of twelve fish samples were analysed, six raw samples and six smoked samples with two fishes sampled from each farm tagged A, B and C. The Proximate and elemental analysis were done using standard procedures. The result of the study showed that moisture content measured in the raw Clarias gariepinus which ranged between (73.074 ± 1.59) % and (71.52 ± 1.83) %. was higher than that of the smoked fish ranging from (26.69±0.03) % to (32.21± 0.02) %. The protein content of smoked fish ranged (43.2±0.02) % to (46.78±0.01) while that of raw fish was between (20.52 ± 1.12) % and (22.15 ± 0.43) %. Similarly, the crude fat, ash, carbohydrate, and fibre content were higher in the smoked fish than raw catfish samples. The elemental composition of both smoked and raw catfish were within the permissible limit of World Health Organization. Arsenic was not detected in the muscle of the raw fish, while cadmium, chromium, lead and magnesium were present in values within WHO permissible limit and similar results was observed for the smoked fish samples. The result of this study presents the possibility of smoked catfish being more nutritious than the raw samples aside from the fact that it has more shelf life than raw fish. Also, both smoked and raw samples of the fish are safe as the values of heavy metal observed were all within the permissible limit of WHO.

EFFECTS OF PROCESSING ON THE PROXIMATE AND MINERAL COMPOSITION OF CULTURED AND CAPTURED CLARIAS GARIEPPINUS

Fish and fish products serve as vital protein sources in Africa and the world in general. Since fish is typically processed before consumption, this study investigated how different processing methods affect the proximate and mineral composition of both cultured and captured Clarias gariepinus. The processing techniques employed in this research included smoking, boiling, and oven drying. Cultured catfish were sourced from Oris Farm in Osogbo, Osun State, Nigeria, while captured catfish were obtained from Asejire Dam in Oyo State. The proximate and mineral compositions of fresh, boiled, smoked, and oven-dried samples of both cultured and captured Clarias gariepinus were analyzed in triplicate. The results indicated significant differences (P<0.05) in crude protein, dry matter, moisture, ash, fiber, potassium, and phosphorus content among the different processing methods for both cultured and captured catfish samples. Potassium and phosphorus levels also varied significantly (P<0.05) across the processing methods. Boiled and oven-dried samples of both cultured and captured catfish exhibited higher crude protein and lipid content, suggesting that these processing methods provide consumers with a rich source of protein and essential nutrients. The study concludes that boiling and oven drying with samples possessing highest percentages of protein are the most effective processing methods for preparing Clarias gariepinus, ensuring optimal nutrient retention for consumers.

Complex patterns of genetic population structure in the mouthbrooding marine catfish, Bagre marinus, in the Gulf of Mexico and U.S. Atlantic.

Patterns of genetic variation reflect interactions among microevolutionary forces that vary in strength with changing demography. Here, patterns of variation within and among samples of the mouthbrooding gafftopsail catfish (Bagre marinus, Family Ariidae) captured in the U.S. Atlantic and throughout the Gulf of Mexico were analyzed using genomics to generate neutral and non-neutral SNP data sets. Because genomic resources are lacking for ariids, linkage disequilibrium network analysis was used to examine patterns of putatively adaptive variation. Finally, historical demographic parameters were estimated from site frequency spectra. The results show four differentiated groups, corresponding to the (1) U.S. Atlantic, and the (2) northeastern, (3) northwestern, and (4) southern Gulf of Mexico. The non-neutral data presented two contrasting signals of structure, one due to increases in diversity moving west to east and north to south, and another to increased heterozygosity in the Atlantic. Demographic analysis suggested that recently reduced long-term effective population size in the Atlantic is likely an important driver of patterns of genetic variation and is consistent with a known reduction in population size potentially due to an epizootic. Overall, patterns of genetic variation resemble that of other fishes that use the same estuarine habitats as nurseries, regardless of the presence/absence of a larval phase, supporting the idea that adult/juvenile behavior and habitat are important predictors of contemporary patterns of genetic structure.

The Significance of Processing Techniques on the Quality of Smoked African Cat Fish (Clarias gariepinus) Using Different Energy Sources

There is unavoidable need for fish smoking as a preservative technique to reduce rampant post harvest losses in the tropical Africa. However the imperative of healthier and quality smoked products through improved processing method were however investigated. Organoleptic and chemical assessment of African catfish collected from a reputable fish farm in Ogbomoso, Oyo state Nigeria was carried out. Eviscerated and non-eviserated fish samples were smoked using four different smoke sources: Gmelina (Gmnelina arborea), Parkia (Parkia biglobosa), Neem (Azadirachita indica) and charcoal. Overall acceptability was based on 5-point Hedonic scale (excellent (5) - poor (1). Chemical test was on Polycyclic Aromatic Hydrocarbon contents (benzo(a)pyrene, Fluoranthene, Napthalene, Acenapthalene, Chrysene and Benzo(ghi) perylene). Data were subjected to one way Analysis of Variance (ANOVA) using general linear mode (GLM) of Factorial Experimental Design and means were separated by Duncan’s multiple range tests (P<0.05). Non- eviscerated smoked African catfish samples had lower scores for colour than eviscerated smoked samples for energy sources used. Eviscerated samples had mean scores of 4.64, 3.91, 3.36 and 2.82 for charcoal, Gmelina, Neem and Parkia smoked samples respectively, much better than scores of 4.36, 2.46, 2.36 and 2.27 obtained for non-eviscerated samples. Total concentrations of polycyclic aromatic hydrocarbons (PAH) were highest in samples produced using Gmelina as smoke source and Neem for eviscerated (15.25 µg/kg) and non-eviscerated (29.43 µg/kg) samples respectively. Evisceration of fish prior to smoking enhances its sensory characteristics however; concentrations of PAHs for both eviscerated and non-eviscerated fish samples were within the recommended international standard limit.

The Prevalence of Trypanosoma Species in Silver Catfish (Bagrus bajad) from Zobe Reservoir, Dutsin-Ma, Katsina State

This research investigates the prevalence of Trypanosoma species in the silver catfish (Bagrus bajad) population in Zobe Reservoir, Dutsin-Ma, Katsina State. The study aims to provide insights into the parasitic infection rates, identify prevalent Trypanosoma species, and assess its potential impacts on the health and population dynamics of silver catfish in the reservoir. A total of 108 silver catfish samples were collected from Zobe Reservoir in Dutsin-Ma, Katsina, Nigeria at bi-weekly intervals, from July-September; 2023 for the discovery of blood parasites and subjected to thorough parasitological examination. Microscopic analysis, including blood smears and tissue samples, was employed to identify and classify Trypanosoma species. Preliminary findings revealed the presence of Trypanosome infections in the silver catfish population, with a variation in prevalence rates among the sampled specimens. The study identifies specific Trypanosoma species affecting the silver catfish in Zobe Reservoir, shedding light on the diversity and distribution of these parasites in the aquatic ecosystem. The Bagrus bajad obtained according to sex indicates 29 males and 79 females were examined. Females had the highest percentage of infection, 10.12%, while males had the lowest percentage of infection, 3.45%. The results of this research contribute valuable data to the understanding of Trypanosome infections in silver catfish populations, with implications for fisheries management, conservation efforts, and the potential transmission of these parasites to other aquatic organisms. Furthermore, the study underscores the importance of continued monitoring and surveillance to assess the dynamic interactions between Trypanosomes and their fish hosts in freshwater ecosystems.

Effects of Ultraviolet Radiation (UVR) on Some Stages of <i>Clarias gariespinus</i> (Catfish) Growth

UVR is a stressor that affect ecological and social systems. It has been noted that UVR presents numerous difficulties for aquatic and human worldwide. It's critical to understand how UVR affects <i>Clarias gariespinus</i> in order to promote healthy fish growth. This study determined how UVR affected catfish. 172 catfish samples were divided into four groups: UV-A, UV-B, UV-C, and controls. The control group was not exposed, whereas the other groups were exposed to UV-A, UV-B, and UV-C, respectively. The exposure period was 131 days, from 8:00 am to 5:00 pm daily. The result on color change shows that UV-C causes a change in color from dark to pink at the fingerling stage and UV-A causes a change in color from dark to slightly pink at the jumbo size, while no color change was observed in other samples. The result on growth rate indicates that the UV-B sample grew faster throughout the period of study, with the highest growth rates of 18.4, 16.2, 14.1, and 8.6 cm for the UV-B, UV-C, control, and UV-A samples, respectively. The result on the mortality rate of the samples shows that the control sample recorded the highest death rate (23) at the fingerling stage, followed by the UV-A (22), UV-C (19), and UV-B (12) samples. The result depicts that UV-B is capable of a rapid increase in the weight, growth, and life span of catfish; hence, exposure of catfish to UV-B can be adopted by fish farmers to improve the healthy fish growth of their farm.

Evaluating contamination of seafood purchased from U.S. retail stores by persistent environmental pollutants, pesticides and veterinary drugs

Studies have reported health risks associated with seafood contamination, but few data exist on levels in commercially available seafood in the US. To better understand, the magnitude of foodborne exposure and identify vulnerable populations in the US, we measured concentrations of veterinary drugs, persistent organic pollutants (POPs) (polycyclic aromatic hydrocarbons [PAHs], polybrominated diphenyl ethers [PBDEs] and polychlorinated biphenyls [PCBs]), and legacy and current-use pesticides in 46 seafood samples purchased from retail outlets. Measured levels were used to estimate risk based on available maximum residue limits (MRLs) and toxic equivalence (TEQ) factors for analytes. Only seventeen of the 445 analytes were detected, at low substance frequencies. However, half of the samples tested positive for one or more analyte, with total concentrations ranging from below the limit of detection (LOD) to as high as 156 µg/kg wet weight. Based on the risk assessment for individual pesticides and veterinary drugs, the hazard quotients (HQ) were all <1, indicating no risk. However, for the sum of PCB126 and PCB167, two dioxin-like PCBs detected in our samples, the TEQ was nearly two orders of magnitude higher than the WHO limits in one catfish sample. Moreover, vulnerable groups with higher rates of consumption of specific fish types may face higher risks.

ESTIMATION OF GENETIC DIVERSITY IN SILVER CATFISH (Chrysicthys nigrodigitatus) USING RANDOM AMPLIFIED POLYMORPHIC DNA

The Silver catfish (Chrysicthys nigrodigitatus) is widely distributed along River Niger.This study was carried out to characterize Silver Catfish found along River Niger, with the help of morphometric and random amplified polymorphic DNA for genetic analysis to determine variation in strain that can be used for identification of the strains and possible allocation. Samples were collected from three stations, namely; Illushi, Illah and Onitsha and total of 1 50 samples (50 each) of silver catfish was collected from landing station. Where 12% of the total sampled fish was used for genetic analysis and 100% of the sample was used for morphometric analysis. Result obtain from the morphometric analysis along River Niger show that dorsal fin length and head length with a value of 0.749 and 0.230 respectively are significantly different (p&lt;0.05) in the sample fish can be used for identification. Result obtained for genetic analysis indicate that samples from the three locations are positively correlated. Value between Illah and Illushi is 0.8991 with a percentage variation of 80%; Onitsha and Illah with a correlated value of 0.79045, a variation of 63% and Onitsha and Illushi with a correlated value of 0.76354 a percentage variation of 50%. Dendogram, Darwin’s hierarchy and Darwin’s radii graph from the study also show that species are from one ancestry. Identification of species for domestication purpose can use morphometric features. Inline breeding between strains in these locations may be necessary to improve strains because of correlation of samples.

Effect of storage temperature on the bacterial flora and sensory quality of vacuum packaged smoked catfish (&lt;i&gt;Clarias anguillaris&lt;/i&gt;)

This study evaluated the effect of two storage temperatures on the bacterial flora and sensory quality of vacuum packaged smoked catfish (Clarias anguillaris). The catfish was hot smoked using a traditional kiln, with mangrove wood as the source of heat. Total bacterial count (TBC) and sensory parameters (colour, smell. dryness and general appearance) were determined during storage at ambient (28 ± 2°C) and refrigeration (4°C) temperatures for 0-8 weeks. Bacteria were enumerated, isolated and identified using standard methods. Vacuum packaged smoked catfish stored at 4°C (VPCR) had the lowest TBC which increased from 3.23 – 3.58 log10 cfu/g within 2 weeks of storage and stabilized at 3.44 log10 cfu/g for 4 – 8 weeks. The TBC of the vacuum packaged smoked catfish stored at ambient temperature (28 ± 2°C) ranged from 3.32 – 6.88 log10 cfu/g within 6 weeks of storage. The bacteria isolated from fresh catfish belonged to nine genera, namely, Bacillus, Chryseobacterium, Escherichia, Lysinibacillus, Proteus, Pseudomonas, Staphylococcus, Streptococcus and Vibrio. Only Bacillus and Proteus species were isolated from freshly smoked catfish. Isolates from vacuum packaged samples were Bacillus, Lactobacillus, Proteus and Staphylococcus. Molecular characterization of three isolates from fresh catfish revealed that the species were Chryseobacterium aquifridigense, Lysinibacillus mycoides and Vibrio parahaemolyticus. The sensory scores for sample VPCR stored for 8 weeks did not differ significantly (P ≥ 0.05) from freshly smoked catfish, except for the colour. Non-packaged and vacuum packaged smoked catfish samples were of good quality during storage at ambient temperature for 4 weeks, and 4 – 6 weeks, respectively.

Proximate Composition and Sensory Evaluation of Catfish (Clarias gariepinus) Smoked with Different Materials

This study determined the proximate and organoleptic properties of smoked Clarias gariepinus using plantain leaves (PL) and foil paper (FP). Twelve catfish samples (570±25g) were euthanized, eviscerated, washed and divided into Control, plantain leaf (PL), and foil paper (FP) before being smoked. The proximate analyses of the initial and smoked samples were done according to standard methods. Organoleptic assessment was done by trained panelists. The result indicated that control sample was preferred in all the organoleptic parameters followed by plantain leaf and foil paper samples. Proximate analyses of the catfish showed that the control sample had the lowest moisture content (19.87±0.59), followed by PL (38.35±0.39), FP (40.46±1.98), and the initial samples (59.78±1.52). Crude protein was 17.45±1.70, 59.03±0.89, 38.28±1.70, and 40.31±0.49 for initial, Control, FP and PL respectively. Crude lipid was 10.32±0.26 (initial), 12.06±0.62 (control), 10.66±0.33 (FP) and 10.51±0.37 (PL). Lipid content of the control sample was significantly different from the other samples. Ash was in the order of Initial (11.65±0.45)&gt;PL (7.55±1.03)&gt;FP (9.88±0.09)&gt;Control (9.40±0.40) while NFE was Initial (1.96±0.95)&gt; Control (0.90±0.18)&gt;FP (0.61±0.35)&gt;PL (0.37±0.18). This study established no significant difference between FP and PL samples while the control was more acceptable and more nutritious in comparison to Plantain leaves and foil paper.

RESPON IKAN NILA (OREOCHROMIS NILOTICUS) DAN IKAN LELE (CLARIAS GARIEPINUS) YANG DIINFEKSI AEROMONAS HYDROPHILLA DENGAN EMPAT TINGKAT PASASE

Tilapia and catfish are some of the freshwater fisheries commodities that occupy the top rank in terms of the amount of production produced. Disease attacks in Tilapia and Catfish cultivation such as Motile Aeromonas Septicemia (MAS) can be detrimental to fish farmers. Motile Aeromonas Septicemia (MAS) disease is caused by the bacteria Aeromonas hydrophilla. This research aims to determine the differences in the physical condition of Tilapia and Catfish which were injected with Aeromonas hydrophilla bacteria and had been treated using the Koch Postulate method four times to reach 50% fish mortality. In this study, the Tilapia and Catfish samples used were 6-8 cm in size with a bacterial infection dose of 0.1ml/fish. Tilapia showed clinical symptoms of thin fins and the injection site began to become inflamed, while catfish experienced bleeding and wounds. Catfish tend to experience more serious injuries after exposure to A. hydrophilla compared to Tilapia due to differences in response to disease symptoms. Tilapia fish show symptoms of loose scales due to bacterial infections such as Aeromonas dhakensis, Pseudomonas mosselii, and Microbacterium paraoxydans.

Analysis of Water Quality and Phagocytic Activity (Clarias Sp.) in Aquaponic and Non-Aquaponic Cultivation Systems

Catfish (Clarias sp.) is one of the many fishery biota that has animal protein which is much loved by Indonesian people. One way to develop environmentally friendly catfish cultivation is through the implementation of an aquaponic biofilter system. This research aims to analyze physical, chemical, and biological water quality parameters in catfish cultivation with and without aquaponics, to obtain a description of the non-specific immune system which is analyzed from the conditions of phagocytic activity of catfish cultivated with and without aquaponics. The method used is by taking samples ten times per week by taking water quality parameters as well as blood samples of catfish raised in ponds with and without aquaponics. The analysis used is the unpaired T-test. Based on the results obtained, it was concluded that all parameters showed that the aquaponic cultivation media was better compared to those without aquaponics.

Heavy metal concentration in blood and selected tissues of cat fish from Kwalkwalawa River, Sokoto

Fish is a cheap source of omega- 3 polyunsaturated fatty acids for humans. However, the presence of toxic heavy metals in water can be detrimental to both fish and humans. The aim of this study was to investigate the levels of heavy metals in the liver, kidney and gills of cat fish obtained from Kwalkwalawa River, Sokoto. Water, sediments, blood and tissue samples of (10) cat fish (Clarias gariepinus) species caught from Kwalkwalawa river were analysed quantitatively for the presence of zinc, copper, lead, chromium and cadmium using atomic absorption spectrophotometer. Bioaccumulation of these heavy metals was estimated in these organs. Results showed that lead concentrations in the water was significantly higher (p &lt; 0.05) compared to the sediment sample. Also, copper and lead accumulated most in the liver and kidney when compared with that observed for the gills. In conclusion, lead and cadmium levels in the samples were above WHO certified limits hence the concentration of metals in this water should be monitored periodically.

Effect of Some Preservatives on the Microbial Quality of Cold-smoked Catfish at Refrigerated Temperature

Aim: This study investigated the preservative effect of potassium sorbate, ginger, garlic, and a blend of, ginger and garlic on the microbiological quality and shelf stability of cold smoked Catfish (Clarius gariepinus) at refrigerated storage.&#x0D; Methodology: One hundred (100) of the freshly harvested catfish obtained from the MOUAU Fish Farm were processed and divided into five lots of 20 each. Four marinating baths containing 0.5% potassium sorbate, 3% ginger, 3% garlic, and a blend of 1.5% ginger and 1.5% garlic respectively were prepared. Each catfish lot except the fifth lot (which served as a control) was marinated for 2 h and cold smoked for 8 h. The samples were then stored for fourteen days at refrigeration temperature (4 ± 2 °C during which analyses were carried out. The Total viable count, Total fungal count, and bacterial counts (Escherichia coli, Salmonella, Staphylococcus sp, and Listeria sp) of the catfish samples before, during, and after storage were analyzed.&#x0D; Results: The total viable count (TVC) was reduced from 8.7x105 to 1.2x105 CFU/g, 1.13 x106 to 2.4x105 CFU/g, 1.09 x 106 to 2.00 x105 CFU/g, 9.60 x105 to 1.50 x105 CFU/g, and 1.19x106 to 3.00x105 CFU/g for 3% ginger, 3% garlic, 1.5% ginger +1.5% garlic, 0.5% potassium sorbate, and the control at refrigeration storage respectively. All the treatments were effective against E. coli, Listeria monocytogen, and Salmonella count. Similarly, the 3% of ginger treatment recorded counts of 1x105 CFU/g for Staphylococcus counts, during refrigeration storage. Furthermore, the total fungal count decreased for all the treatments.&#x0D; Conclusion: The study found that cold smoked catfish treated with 0.5% potassium sorbate, 3% ginger, 3% garlic and a blend of 1.5% ginger and 1.5% garlic can be stored for 14 days at refrigeration storage provided the storage condition is maintained.

The Potential of Sponge-Associated Bacillus spp. as A Biocontrol Agent to Inhibit Several Bacteria from Infected Catfish (Clarias gariepinus Burch)

Catfish is one of the freshwater aquaculture commodities with a high level of consumption and production in Indonesia. Disease outbreaks could occur in catfish farming activities caused by pathogenic bacteria. Several species of pathogenic bacteria can cause disease in catfish, resulting in mass death. This can lead to decrease in the food quality of freshwater fishery products, especially catfish. In cultured system, aquaculture occurrence of diseases can cause severe financial losses. Catfish samples were obtained from catfish farming with clinical symptoms of reddish spots on the outside of the body. Bacteria were isolated from the kidney and liver under aseptic conditions. These bacteria isolates were identified through their colony morphology, Gram staining, biochemical tests, molecular test, and antibacterial test of Bacillus spp. using spot and disc diffusion test. Identification based on 16S rRNA gene showed that GL1 was 99.92% closely related to Aeromonas widowei, HL1 was 100% closely to Bacillus amyloliquefaciens, and GL2 and HL2 was closely related to Bacillus cereus. The antibacterial test results of APD10 isolates of Bacillus velenzensis species inhibited GL2 pathogenic bacteria with an inhibition zone of 22.15 mm in the very strong inhibition zone and HL2 pathogenic bacteria with an inhibition zone of 8.5 mm in the moderate inhibition zone. Bacillus velezensis was isolated from the sponge Aplysina sp. could be further utilized as a biocontrol agent for the pathogenic bacteria, Bacillus cereus, that infects catfish.

The Potential of Sponge-Associated Bacillus spp. as A Biocontrol Agent to Inhibit Several Bacteria from Infected Catfish (Clarias gariepinus Burch)

Catfish is one of the freshwater aquaculture commodities with a high level of consumption and production in Indonesia. Disease outbreaks could occur in catfish farming activities caused by pathogenic bacteria. Several species of pathogenic bacteria can cause disease in catfish, resulting in mass death. This can lead to decrease in the food quality of freshwater fishery products, especially catfish. In cultured system, aquaculture occurrence of diseases can cause severe financial losses. Catfish samples were obtained from catfish farming with clinical symptoms of reddish spots on the outside of the body. Bacteria were isolated from the kidney and liver under aseptic conditions. These bacteria isolates were identified through their colony morphology, Gram staining, biochemical tests, molecular test, and antibacterial test of Bacillus spp. using spot and disc diffusion test. Identification based on 16S rRNA gene showed that GL1 was 99.92% closely related to Aeromonas widowei, HL1 was 100% closely to Bacillus amyloliquefaciens, and GL2 and HL2 was closely related to Bacillus cereus. The antibacterial test results of APD10 isolates of Bacillus velenzensis species inhibited GL2 pathogenic bacteria with an inhibition zone of 22.15 mm in the very strong inhibition zone and HL2 pathogenic bacteria with an inhibition zone of 8.5 mm in the moderate inhibition zone. Bacillus velezensis was isolated from the sponge Aplysina sp. could be further utilized as a biocontrol agent for the pathogenic bacteria, Bacillus cereus, that infects catfish.

Polychlorinated dibenzo-p-dioxin/dibenzofurans (PCDD/Fs) contamination in sediments and fish from Msimbazi River in Dar es Salam, Tanzania: patterns, sources, and their exposure to humans.

Results of a two-dimensional gas chromatograph time of flight mass spectroscopy (GCXGC-TOFMS) determination of polychlorinated dibenzo-p-dioxin (PCDDs) and polychlorinated dibenzofurans (PCDF) in sediments and catfish samples collected from the Msimbazi River are presented here. Samples were extracted using USEPA Method 1613. PCDD/Fs congeners in sediments ranged from 2.0 to 393.0 and 0.7 to 654.8pg/g in the dry and wet seasons, respectively. 1,2,3,4,7,8,9-HepCDF was detected at the highest concentration, but all were lower than the USA action level of 1000pg/g. Toxicity for each of the sampling points ranged from 19.7 to 36.5, with a mean concentration of 27.0pg WHO 2005-TEQ g-1 in the dry season and 2.0 to 38.7 with a mean concentration of 20.7pg WHO 2005-TEQ g-1 in the wet season. Analysis of variance (ANOVA) showed that there was no significant difference between PCDD/Fs TEQ during the dry and wet seasons (p = 0.08; α = 0.05). The highest TEQ value was estimated at Jangwani in the wet season. Toxicity of PCDD/Fs in catfish collected from the Msimbazi River ranged from 9.3 to 145.2, with a mean of 61.2pg WHO2005-TEQg-1. Tetrachlorodibenzo dioxin (2, 3, 7, and 8-TCDD) was detected in all fish samples and ranged from 3.5 to 12.7 with a mean of 8.1pg/g. The concentration of TCDD in fish exceeded the Agency for Toxic Substance and Diseases Registry MRL, thus posing a probable high risk to people whose dietary requirements depend on fish from the Msimbazi River.

Techno-Economic Assessment of a Rotatable Fish Grill for Charcoal and Briquette

Charcoal and briquette fuel material were each assessed for use in a locally manufactured rotatable fish grill. Fresh African Catfish (Clarias gariepinus) samples averagely weighing 500±54g were taken from a fishpond managed under a recirculating aquaculture system (RAS) at the study location. Three repetitions of a Completely Randomized Design (CRD) were used, and LSD was calculated at p ≤ 0.05. The findings indicate that compared to briquette fuel material, charcoal used much more energy. Similarly, grilling using charcoal required much more time (53 minutes) than grilling with briquettes (37 minutes). The energy efficiency of the grill did not differ significantly between charcoal (93.6%) and briquette (92.9%). Similarly, no significant difference in specific fuel consumption was observed for charcoal (1.06) and briquette (0.90) fuel material. Fish grilled over charcoal or briquette produced cooking yields of 72% and 70%, respectively. Breakeven for charcoal and briquette assuming the grill is under a custom hiring arrangement was estimated at 1010.9 hours and 991.83 hours, respectively. Future studies should examine organoleptic evaluation of fish grilled on rotatable grills to determine whether the finished product is acceptable to consumers. Nile Tilapia (Oreochromis niloticus) could be the subject of a similar investigation. &nbsp

Study of some toxic metals in parts from catfish (Silurus triostegus) in Shatt Al-Arab river

According to their toxicity, toxic heavy metals such as arsenic, mercury, cadmium, copper, zinc, and lead are believed to be the most harmful to humans, fish, and the environment. Because their levels are rising due to human activities endangering aquatic species and people, the current study sought to ascertain the level of toxic heavy metals in five catfish parts (skin, liver, muscles, gills, and ovaries). In the northern part of the Shatt Al-Arab, catfish samples were collected in March 2022. ICP-MS was used to detect target metal levels. According to the results, arsenic accumulated in the skin and muscles at a rate of 0.22 and 0.21ppm, respectively. In contrast, the levels of arsenic in the various body parts are not statistically different. Additionally, cadmium showed no noticeable variances in the studied body parts. Furthermore, the liver had the most significant copper accumulation 18.72ppm. Furthermore, mercury accumulation in various body parts was shown to vary statistically, with the highest levels in muscles 0.66ppm. In addition, zinc was accumulated in the body parts in the following sequence: gills, ovaries, liver, skin, and muscles, respectively, while in the following sequence: muscles, skin, gills, liver, and ovaries respectively in the lead. Moreover, there were no statistically significant differences in the quantity of zirconium that accumulated. According to the current study, the catfish’s body parts did not accumulate toxic heavy metals at high rates. This may be due to study area the environment and the mechanisms of treating these types of metals by catfish.

Microplastic Accumulation in Catfish and Its Effects on Fish Eggs from Songkhla Lagoon, Thailand

Microplastics have been found to accumulate in freshwater, marine ecosystems, and biological organisms. The frequency of studies on microplastic contamination in organs has increased recently, although there have been relatively fewer investigations on fish eggs in Thailand. To extract microplastics from catfish samples for laboratory analysis (Osteogeneiosus militaris), we used 10% potassium hydroxide in the digestion process. A needle penetrated the fish eggs to investigate microplastic contamination. We examined microplastics under a stereomicroscope and used Fourier transform infrared spectroscopy to determine the type of polymer. We found microplastic contamination in organs, most commonly in the stomach (0.91 ± 0.13 items/g), followed by tissue (0.53 ± 0.09 items/g), and gills (0.30 ± 0.03 items/g) at the level of significance p &lt; 0.01. We found a total of 349 fish eggs with 27 items of microplastic. The dominant microplastic we found in the stomach, tissue, and gills of the fish, as well as in fish eggs, was of fiber shape. We noted that fragments were found only in the stomach and tissue of fish. The dominant color of microplastics was black in organs and blue in fish eggs. The common polymer types in organs and fish eggs were polyethylene terephthalate, polypropylene, and cellulosic fiber.