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The impact of dietary fenugreek (FN) supplementation on growth performance, physio‐metabolic enzyme response, and antioxidant enzyme activities in hybrid African catfish (Clarias gariepinus ♀ × Heterobranchus bidorsalis ♂) was investigated in this study. Five isonitrogenous diets (38% crude protein) were developed and fed to the fish for 60 days. The FN was incorporated into the diets at 0%, 0.5%, 1.0%, 1.5%, and 2%. Two hundred twenty‐five fingerlings of hybrid African catfish (average weight 4.01 g ± 0.02) were used for the study and randomly distributed to five dietary groups in triplicate. FN supplementation improved growth responses and survival rates; the dietary groups considerably (p < 0.05) outperformed the control group. FN‐based diets considerably increased the carcass protein content (p = 0.020) and improved protein retention (p = 0.015). FN supplementation markedly (p < 0.001) and dose‐dependently reduced the carcass's lipid content and substantially (p < 0.001) increased the levels of metabolic enzymes. The fish antioxidant capacity was significantly enhanced (p < 0.001), and hepatic stress enzymes were greatly (p < 0.001) lowered in FN‐based diets. In summary, the second‐order polynomial regression analysis indicates that the optimal dose of FN supplementation to improve hybrid catfish growth without negatively affecting the fish's physio‐metabolic response or overall wellbeing is 1% dietary inclusion level. [ABSTRACT FROM AUTHOR]

As nutrient-rich water in aquaponic systems cannot supply growing plants with all the required trace elements, supplementation with specific fertilizers is performed to make up for this deficit. While chelated fertilizers such as ethylenediaminetetraacetic acid-zinc disodium complex (Zn-EDTA) are becoming more popular in this context for improving plant growth in aquaponic systems, little is known about their effects on fish. During two experiments, a total of 576 individuals of catfish fry (0.19 g) and fingerlings (220.01 g) of the African catfish (Clarias gariepinus; Burchell, 1822) were kept separately for 32 days under experimental aquarium conditions. The fry was exposed to 0.125 and 0.5 mg/L, while the fingerlings were exposed to 0.5 and 2.0 mg/L Zn-EDTA in a plantless aquaponic system. The third treatment group consisted of a control group without Zn-EDTA. The growth, mortality, and ethological indicators were assessed for all growth stages, while the leukocyte distribution and histopathological changes were additionally determined for the fingerlings. As the feed intake in the experiment was limited, the investigations were focused on the effects of Zn-EDTA and not on the growth process of a respective fish growth stage. While the growth, mortality, and behavior were not significantly different in both growing stages, the number of mature neutrophils changed significantly in all treatments in fingerlings. Zn was not detected in the histologically investigated organs at the tested concentrations using the staining method. However, morphological alterations of the gill epithelium were found on the secondary lamellae. Quantitative multiplex PCR was used to simultaneously evaluate the expression of 17 genes related to Zn metabolism and stress physiology in head kidney samples. The transcripts of several selected genes changed by up to 70-fold. Due to high individual variances, only the copy numbers of the KMT2A (lysinespecific methyltransferase 2a) gene were significantly different across treatment groups and sampling points. However, the present results indicate that the addition of Zn-EDTA at the tested concentrations can be considered relatively benign for the health and welfare of C. gariepinus, as no toxic effects of Zn-EDTAwere observed in moderately hard to hard water. [ABSTRACT FROM AUTHOR]

Fish gut is a versatile organ serving as the primary pathway for invasion by pathogens, particularly parasites, playing a crucial role in modulating the intestinal adaptive immune response. This study aimed to investigate the cellular-mediated reaction, mucosal acidity, and the expression of proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), and CD68 in the intestines of catfish, Clarias gariepinus, naturally infected with helminths. Forty catfish were collected from the Nile River and examined for intestinal parasites. The intestinal tissues of the control and infected fish were fixed for histochemical and immunohistochemical studies. Two groups of helminths were found: cestodes Tetracampos ciliotheca and Polyonchobothrium clarias, and nematodes Paracamallanus cyathopharynx, with a prevalence rate of 63.63%, 18.0%, and 18.0%, respectively. Our results showed that the infected fish had a statistically significant rise in the activity of immune cells, including mast cells, eosinophil granular cells, and dendritic cells. This correlated with upregulation in the expressions of PCNA, VEGF, and CD68. Histochemical analyses demonstrated a marked increase in acidic mucus production, Sudan black B, and bromophenol mercury blue. This study enriches our understanding of the evolution of vertebrate immunity in combating intestinal parasitic infections and the host's adaptive responses. [ABSTRACT FROM AUTHOR]

Astronomical discharge of facial cosmetic products into the aquatic environments exposes aquatic organisms to these pollutants. Eight facial cosmetic products such as Milani Powder, Ponds Primer, Zikel Powder, Zaron concealer, Glam gal's foundation, Maybelline foundation, L.A Girl concealer and Milk of Magnesia were evaluated for relative acute toxicity (single and joint action) against Clarias gariepinus in static laboratory bioassays. Single action toxicity data were statistically analysed based on Probit, while the Synergistic Ratio and Concentration - Addition analysed joint action. Results of acute toxicity (single action) based on 96hrLC50 values showed that Milani Powder (184.14 mg/l) was the most toxic, followed by Ponds Primer (230.95 mg/l), Zikel powder (233.58 mg/l), Aaron concealer (384.47 mg/l), Glam Gals' foundation (421.83 mg/l), Maybelline foundation (565.32 mg/l), L, A Girl concealer (587.75 mg/l) and Milk of Magnesia (2218 mg/l) in descending order of toxicity. Joint action toxicity evaluation of the binary, trinary and quaternary mixtures subjected to the Synergistic Ratio and Concentration showed that binary mixtures tended towards synergism and antagonism in varied ratios and combinations. The ratio of toxicity units for all mixtures interaction tended to synergism and could be dangerous to the biota. Therefore, strict regulation standards should be enforced to protect the environment and make eco-friendly alternative ingredients that can be incorporated into these products. [ABSTRACT FROM AUTHOR]

The study of length-weight relationship and condition factor was carried out on of freshwater catfish, Clupisoma garua. Altogether 280 samples were collected from three different rivers of North India (Gomti, Ganga and Rapti). The value of b ranges from 2.571-2.720 for the length-weight relationship in the current study. The growth pattern showed significant deviation from isometric value (b=3), therefore all the three populations are supposed to follow negative allometric growth pattern. The coefficient of determination (r2) was found to be in the range of 0.8059-0.8587. The value of condition factor in the present study was found to be more than '1' in all the three populations of the fish which indicated the good health conditions. The present study is considered to be important for assessment of the biology of the fish that could help in conservation and management of C. garua in the North Indian Rivers. [ABSTRACT FROM AUTHOR]

African catfish is a popular freshwater aquaculture species as it can be farmed at high stocking density. However, high stocking density caused growth and health impairment. Hence, nutritional approach such as feed additive can be applied in fish farming to overcome this issue. This study evaluated the impacts of ginger (Zingiber officinale) leaf powder (GLP) on growth performance, digestive enzymes activities, antioxidative response, and disease resistance towards Edwardsiella tarda infection in African catfish. A feeding trial was performed using a control diet and four formulated diets with GLP at 1, 2, 3, and 4%. Ginger is an herb used in cuisine and traditional medicine. It was reported possesses medicinal values such as antimicrobial, anti-oxidant, and immune system modulator. After eight weeks, the growth performance of GLP-treated African catfish was significantly improved than control, and the best results were observed in the 2 and 3% groups (p<0.05). Meanwhile, fish supplemented with 1 and 4% GLP demonstrated comparable growth performance. There was a significant decreasing trend in FCR, HSI, and VI, where the lowest values were recorded by the 2 and 3% GLP diet groups, followed by 1% GLP, 4% GLP, and control groups (p<0.05). The digestive enzymes activity, including amylase, lipase, and protease, was significantly higher in dietary GLP groups than in control, where the highest activity was exhibited by groups 2 and 3% GLP (p<0.05), followed by 1% and 4% GLP groups. There was an increasing trend in the antioxidative response, where the GLP-treated groups had significantly higher catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) activities than the control, and the highest was observed in fish fed with 2 and 3% GLP (p<0.05). Furthermore, the GLP-treated groups had a significantly higher cumulative survival rate than the control, where 2 and 3% GLP groups demonstrated the highest survival (p<0.05), followed by 1 and 4% GLP groups. In summary, this study revealed that dietary GLP potentially enhanced African catfish production at recommended doses of 2 and 3%. [ABSTRACT FROM AUTHOR]

Simple Summary: Personality and light are crucial to ensure the welfare of aquatic animals. To understand how personality affects the light color selection of fish, we tested the behaviors with different personalities under six colors of light: violet (410–420 nm), yellow (580–590 nm), green (550–560 nm), red (620–630 nm), blue (470–480 nm), and white. In this study, the yellow catfish Pelteobagrus fulvidraco preferred the yellow and green light over the other light colors. After identifying their preferred light colors, bold individuals reduced their frequency of exploration. The results showed that bold individuals could make a quick decision for light color selection. This study provides a reference for the welfare of juvenile yellow catfish in aquaculture. Personality, which matters for animal welfare, demonstrates behavioral differences. Light is one of the most important factors in aquaculture. However, how fish personality affects light color selection is unclear. In this study, we tested the personality of yellow catfish Pelteobagrus fulvidraco juveniles and then quantified the selective behaviors of different personalities under six light colors: violet (410–420 nm), yellow (580–590 nm), green (550–560 nm), red (620–630 nm), blue (470–480 nm), and white. The results showed that juveniles preferred the yellow and green light over the other colors of light, probably due to different reasons. The average cumulative dwell time in yellow (32.81 ± 5.22%), green (21.81 ± 3.58%), and red (26.36 ± 4.89%) lights was significantly longer than the other light colors, and the average visit frequency in green light (32.00 ± 4.93%) was the most. Juveniles had the longest total moved distance in green light. Moreover, the results demonstrated that shy and bold individuals had the same preference for the green light. Bold individuals could find the preferred light colors rapidly and make quick decisions for light color selection. After identifying the preferred light colors, bold individuals reduced the frequency of exploration. This study provides a theoretical basis for the welfare of juvenile yellow catfish in aquaculture. [ABSTRACT FROM AUTHOR]

Studies have emphasized that the presence of heavy metals in freshwater fish represents a global public health issue. Nigeria, being a developing nation with less emphasis on the quality of seafood consumed by the residents, ranks this study very vital. The policy implication of this study is the advancement of a healthy population in contemporary Nigeria. Hence, this study assessed heavy metal concentration in two fish species, Clarias gariepinus (Catfish) and Oreochromis niloticus (Nile Tilapia), in the Anambra River. The sample included twenty fishes, of which eighteen were collected from the three sampling locations (the fish ports of Anambra River), namely Otu-nsugbe, Otuocha, and Ikemivite) while two control samples were collected from a pond about 200 m away from the river. The levels of heavy metals were determined using Varian AA 240 atomic absorption spectrophotometer (AAS). The results showed that the concentrations of heavy metals (cadmium and arsenic) in the sampled fishes from Anambra River exceeded the joint World Health Organization and Food and Agriculture Organization (FAO/WHO) standard for fish and fish product consumption, while the concentration of chromium, mercury, and lead are within the permissible limit. The study also showed the distribution of the heavy metals in the fish organ varies among fish species. Heavy metals occur higher in Clarias garepinus than in Oreochromis niloticus, while tissue preference for heavy metal accumulation is in the order of gill > liver > muscle. It was recorded from this study that the heavy metal concentration in the fish from the pond is generally higher than the fish from the river for some metals. The high level of heavy metals in the sampled fish was attributed to heavy metals contamination of the river as a result of various anthropogenic activities such as mining, burning of fossil fuel and emission from the exhaust of boats/vehicles, overuse of fertilizers and pesticides, discharge of effluent, sewage, and hospital waste. This study concluded that long-term consumption of fish from the river may pose health risks to the consumers due to the possible bioaccumulation of heavy metals, especially cadmium and arsenic. It was recommended that continuous monitoring of heavy metal levels in the fish and water, public awareness, and appropriate legislative provisions should be put in place to ensure that harvested fish and fish products may be safe for human consumption. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate cinnamaldehyde (CN) and clove oil (CO) effectiveness in inhibiting growth and killing spoilage and total aerobic bacteria when overlaid with catfish fillet stored at 4 °C. A 1.00 mL concentration of CO inhibited growth by 2.90, 1.96, and 1.96 cm, respectively, for S. baltica, A. hydrophilia, and total bacteria. Similarly, treatment with 1.00 mL of CN resulted in ZIB of 2.17, 2.10, and 1.10 cm, respectively, for S. baltica, A. hydrophilia, and total bacteria from catfish exudates. Total bacteria from catfish exudates treated with 0.50 mL CN for 40 min, resulted in a 6.84 log decrease, and treatment with 1.00 mL resulted in a 5.66 log decrease at 40 min. Total bacteria exudates treated with 0.50 mL CO resulted in a 9.69 log reduction at 40 min. Total bacteria treated with 1.00 mL CO resulted in a 7.69 log decrease at 7 days, while untreated pads overlaid with catfish resulted in ≥9.00 CFU/mL. However, treated absorbent pads with catfish at 7 days, using 0.50 mL and 1.00 mL CN, had a bacterial recovery of 5.53 and 1.88 log CFU/mL, respectively. Furthermore, CO at 0.50 mL and 1.00 mL reduced the bacteria count to 5.21 and 1.53 log CFU/mL, respectively, at day 7. [ABSTRACT FROM AUTHOR]

The North African catfish (Clarias gariepinus) is a significant species in aquaculture, which is crucial for ensuring food and nutrition security. Their high adaptability to diverse environments has led to an increase in the number of farms that are available for their production. However, long-term closed breeding adversely affects their reproductive performance, leading to a decrease in production efficiency. This is possibly caused by inbreeding depression. To investigate the root cause of this issue, the genetic diversity of captive North African catfish populations was assessed in this study. Microsatellite genotyping and mitochondrial DNA D-loop sequencing were applied to 136 catfish specimens, collected from three populations captured for breeding in Thailand. Interestingly, extremely low inbreeding coefficients were obtained within each population, and distinct genetic diversity was observed among the three populations, indicating that their genetic origins are markedly different. This suggests that outbreeding depression by genetic admixture among currently captured populations of different origins may account for the low productivity of the North African catfish in Thailand. Genetic improvement of the North African catfish populations is required by introducing new populations whose origins are clearly known. This strategy should be systematically integrated into breeding programs to establish an ideal founder stock for selective breeding. [ABSTRACT FROM AUTHOR]

Triethylene glycol (TEG) removes equilibrium water from natural gas but may spill during equipment maintenance and other poor safety practices. Studies on the toxicity of rich TEG in aquatic habitats are scarce. In this study, the toxicity of rich TEG on freshwater juvenile African catfish (Clarias gariepinus) test organism was conducted. The experimental design for the toxicity tests was 3 × 5 × 6 factor in a randomized complete block design, with six levels of treatment, observed at five intervals and in three replicates. The acute toxicity was carried out by exposing them to various lethal concentrations of the Rich TEG in solution. Physicochemical parameters, including temperature, dissolved oxygen, pH, conductivity, and total dissolved solids, were measured and recorded for five test concentrations of 25.92, 12.96, 6.48, 3.24, 1.62, and 0.0 ml/l (control). The concentration responses for the fish mortality at 24, 48, 72, and 96 h were also derived. No mortality was observed between Rich TEG concentrations of 0 ml/l to 25.92 ml/l after 72 h of exposure. However, some mortality was observed between 1.62 ml/l to 25.92 ml/l after 96 h of exposure. The highest concentration of 25.92 ml/l recorded a higher mortality of 6.0 ± 0.4, which is an average of 60%, while the lowest mortality was recorded in the control (0 ml/l), at an average of 0% mortality rate. The results underscore the concentration-dependent effects of rich TEG on the test organism, highlighting the need for targeted attention to higher concentration levels. [ABSTRACT FROM AUTHOR]

The culture of African catfish, Clarias gariepinus, is constrained by the high mortality of fry, occasioning a shortage of high-quality seeds for stocking by farmers. Asia, a continent with many success stories for aquaculture, leads in farmed production of some catfishes, a diverse group of 37 different families. Globally, the culture of catfishes ranks fifth in global farmed finfish production. Globally, Vietnam leads in the production and export of farmed striped catfish, Pangasianodon hypophthalmus, with 1,400,000 tonnes produced annually from about 7,000 hectares. Similarly, China farmed the non-native Channel catfish, Ictalurus punctatus, into the major crop, with a current annual production of 250,000 tonnes. On the contrary, C. gariepinus, the main farmed catfish species in Africa, records low annual yields, with 240,000 tonnes for the whole continent. This paper explores the factors behind the high production of P. hypophthalmus and I. punctatus in Vietnam and China, respectively, and draws lessons for C. gariepinus farmers in Africa. Specifically, the use of differentiated hatchery and nursery husbandry practices was critical in boosting seed production, quantity, availability, and distribution for expanding the culture of P. hypophthalmus in Vietnam. Improvement of fish species through well-designed genetic improvement programs helped China substantially increase production of I. punctatus. For both species, intensive fish production, as well as the adoption and implementation of suitable policies, increased seed production from hatcheries in both countries. These are discussed as some of the factors that spurred catfish production in the two Asian countries. We argue that if these are adopted by farmers in Africa, they could help improve the production of farmed C. gariepinus on the continent for food and nutrition security as well as generation of livelihood for local communities. [ABSTRACT FROM AUTHOR]

The study of diet is one of the mechanisms by which competition for resources between species that cohabit in the same ecosystem can be inferred. Therefore, the relationships of the indices that measure specialization in the diet of fish species are necessary to characterize the nutritional quality of these populations and the ecosystem's environmental health. Three species of catfish were selected: one invasive (Clarias gariepinus) and two natives (Trachelyopterus striatulus and Rhamdia quelen), with similar distribution along the Guapi‐Macacu River, in the Guapimirim Protection Area (Rio de Janeiro). Fifty‐nine catfish of the three species were collected in total, along 32 collection points in the Guapi‐Macacu River in two periods (dry and rainy) in 2018. Non‐parametric statistics showed the partition of resources between species and the influence of abiotic factors (temperature, pH, transparency, and dissolved oxygen) contributing to the selection of available resources in the environment. Diet‐related indices—repletion index (RI), condition factor (K), niche width, and trophic position (TP) of the specimens collected—contributed to measuring the nutritional status of each of these catfish species, showing that R. quelen has a relationship between RI and K, tending to absorb and metabolize nutrients faster than other species. In addition, the invasive species occupies a wide range of TPs compared to native species, confirming its feeding plasticity. On the contrary, T. striatulus needs large amounts of terrestrial insects to maintain its poor condition factor. Also, the RI showed direct influences of abiotic variables, with the temperature being the most prominent. Our results suggest that the invasive species can benefit from this environment that shows signs of environmental degradation. [ABSTRACT FROM AUTHOR]

The African catfish Clarias gariepinus is a freshwater species native to nearly all of Africa and a small part of Asia. Due to being a generalist species, highly fertile and able to survive in a wide range of environmental conditions, the African catfish has become invasive in many non-native systems where it was introduced, bringing negative impacts to wild ecosystems. In Brazil, C. gariepinus was introduced from Africa for aquaculture in 1986 and established itself in the wild within a decade, after escaping from aquaculture ponds and being further translocated to be used in recreational fishing. As further evidence of the expansion of this invasive species in Brazil, we sequenced the mitochondrial control region and cytochrome b markers to confirm the occurrence of C. gariepinus in a major river in a protected area in the southeastern region, and to assess its genetic diversity. Morphometric data was also collected to aid species identification and to compare to other invasive populations in Brazil. The analysis of 24 specimens revealed a single haplotype for each marker. The single cytochrome b haplotype is identical to a haplotype from the Democratic Republic of the Congo, unveiling the possible genetic origin of the C. gariepinus lineage that invaded Brazil. Morphometric data suggests consistency in the morphometric traits of C. gariepinus invasive populations in Brazil. The assessment and monitoring of the distribution of C. gariepinus in non-native areas are crucial for the maintenance of native freshwater biodiversity and ecosystem functioning worldwide. [ABSTRACT FROM AUTHOR]

Background: Aeromonas species are one of the most important etiologies of diseases in fish farms, leading to clinical manifestation and mortality and are associated with public health risks. This study aimed to investigate the prevalence, phenotypic and molecular characteristics of Aeromonas species isolated from farmed Clarias gariepinus using 16 S rRNA sequencing. Additionally, their antibiogram and multiple antibiotic resistance index were determined using a disc diffusion test. Results: A total of 230 Aeromonas strains were isolated from Clarias gariepinus with 40.9% obtained from diseased fish, and 25% isolated from apparently healthy ones. Five different species including Aeromonas caviae, Aeromonas veronii, Aeromonas hydrophila, Aeromonas dhakensis and Aeromonas enteropelogenes were fully identified and genetically characterized. Based on the available literature, this is the first report of Aeromonas enteropelogenes from the study area. The phylogenetic analysis showed genetic heterogeneity and distance within the species and the reference strains. The multiple resistant Aeromonas species were susceptible to ciprofloxacin, gentamycin, and florfenicol. The Aeromonas species' multiple antibiotic resistance index values varied between 0.20 and 0.80 and were isolated from the farms where antibiotics were intensively used. Conclusions: The diversity of multidrug-resistant Aeromonas species isolated from fish farms is a major threat to fish production giving us more understanding of epidemiology and the multidrug Aeromonas species with a MAR index of greater than 0.2 were isolated from farms where antibiotic use was widespread. As a result, a considerably increased danger of multiple antibiotic resistance spreading to the fish culture environment may impact aquaculture production. Hence there is a need for appropriate and monitored drug usage. [ABSTRACT FROM AUTHOR]

Background: Babesiosomes are apicomplexan parasites of both marine and freshwater fish species. Aim: In this study, we recorded the prevalence of Babesiosoma spp in two Egyptian freshwater fish species; the common carp and the African catfish with full pathological evaluation of the diseased condition, hematological and biochemical analysis of some parameters with exact recognition of the parasite with different methods. Methods: Two hundred and forty fish blood samples from Al-Sharqiya and Al-Ismailia governorates from August 2022 to January 2023 followed by blood film examinations, performing electron microscopy and molecular detection of the parasite via polymerase chain reaction. Results: The total infection prevalence was 63.75% with a higher prevalence observed among African catfish (42.5%) than Common carp (21.25%). Regarding hematologic parameters, the obtained results showed a significant decrease in the hematocrit values and a significant increase in the total leukocyte and lymphocyte values in both infected fish species. The serum ferritin, superoxide dismutase, and glutathione peroxidase were also significantly increased. However, the total iron binding capacity was significantly decreased. There was also a significant increase in the total serum bilirubin in the examined fish, all at (p < 0.001). Histopathologically, the lesions were more intense in the African catfish than the common carp but generally, the infected fish showed many changes with the gills being severely affected with pronounced hyperplasia of secondary lamellae with fusion and telangiectasis. The spleen, heart, and kidney are also affected. Conclusion: Serious adverse effects on the health status of previously examined fishes infected with Babesia spp. were observed and detected by several diagnostic and descriptive tools. Histopathological, hematological, and biochemical studies give an idea of the extent of these changes which are largely fatal affecting the economic system depending on the fish industry. [ABSTRACT FROM AUTHOR]

The purpose of this research is to find out the optimal dose of galangal extract to treatment of Sangkuriang catfish infected with Aeromonas hydrophila, the fish fry used are 5-7 cm in size. October-November 2022 was the research was carried out by an experimental method using a completely randomized design (CRD) with four treatments and three replications. The treatment used was immersing with galangal extract for 24 hours with doses of 0 mg/L (A), 250 mg/L (B), 500 mg/L (C) and 750 mg/L (D). Maintenance of test fish for 14 days. Aeromonas hydrophila bacteria are used to infect fish with a density of 108 CFU/mL by immersing 10 ml in 10 liters of water. Clinical symptoms of infection, clinical symptoms of recovery period, survival rate and water quality were used as parameters in this research. The results showed that the use of galangal extract for treatment of Sangkuriang catfish fry infected with Aeromonas hydrophila by immersion method for 24 hours at a concentration of 500 mg/L was the best treatment with the survival rate of 90%. [ABSTRACT FROM AUTHOR]

In this study, twenty fresh African catfish (Clarias gariepinus) and silver catfish (Bagrus bayad) fillets as well as twenty frozen pangasius catfish (Pangasianodon hypophthalmus) fillets were collected from Egyptian local markets and retailers during 2021. Pangasius catfish fillets can be divided into two grades: white basa fillets (grade I, white colour) and red basa fillets (grade II, pale pink to red colour). This study aimed to assess the physical (colour and shear force), chemical (pH, TVB-N and TBARS) and sensory parameters of catfish fillet samples. The sensory attributes of raw catfish fillets were measured using a 9-point hedonic scale and these attributes include colour and appearance, odor, texture, and overall acceptability. The results of the proximate composition showed that the African catfish and silver catfish fillets had significantly lower moisture (76.12-76.94) and higher crude protein (17.19-17.24) and fat levels (3.35-4.12) compared to the frozen Pangasius catfish fillets. The total volatile basic nitrogen (TVB-N) ranged from 6.83 to 16.38 mg/100g, thiobarbituric acidreactive substances (TBARS) values ranged from 0.35 to 1.01 mg malonaldehyde/kg and pH ranged from 6.43 to 7.35. The TVB-N and TBARS values of examined catfish fillets were within acceptable limits. The African catfish fillets were darker and characterized by higher redness (a*) and lower yellowness (b*) values as well as higher shear force values (9.52 kgf/m3 ), while white basa fillet was the lowest darkness, less saturated with the red pigment (a*) and more saturated with the yellow component (b*) as well as lower shear values (2.17 kgf/m3 ) among the examined catfish fillets. African catfish and silver catfish fillets showed significantly higher sensory scores than the Pangasius catfish fillets. All the organoleptic properties of raw catfish fillets were above the rejection threshold score (≤4.0) In conclusion, catfish fillets were of superior quality and acceptable for human consumption. [ABSTRACT FROM AUTHOR]

The study evaluated comparative effects of formulated soybean diets on the development of juvenile catfish (C. gariepinus) at the Fishery unit, Federal College of Forestry Jos (FCF, Jos), Plateau State Nigeria. The parameters assessed were length, width, weight gain and survival rate; the experimental period was 6 weeks (42days). A total of 150 C.gariepinus fingerlings were purchased at the Fishery unit, FCF, Jos for the experimental study. The experimental setup comprised five treatments and each replicated. The trial layout was a randomized complete block design (RCBD) utilizing five (5) treatments; with one (1) control. Collected data was analysed using ANOVA and average values were isolated utilizing the New Duncan multiple range test at 5% (p = 0.05) likelihood level. Diet formulation was done using a Pearson square method. The graded inclusion levels of the soybean diets [soybean residue (SBR) and soybean meal (SBM)] were: Treatment one (T1) (100% SBR); Treatment 2 (T2) (25% SBR/75% SBM); Treatment 3 (T3) (50% SBR / 50% SBM); Treatment 4 (T4) (75% SBR/25% SBM); and Treatment 5 (T5) (100% Control). The results revealed that C.gariepinus fingerlings in T5 indicated pre-eminent values for the growth parameters with regards to average length (7.00cm), width (2.48cm), weight gain (0.52kg) and survival rate (97%). Therefore, this study recommends increased utilization of soybean meal (100%) formulated at 44% crude proteins as the central diet for C.gariepinus fingerlings; intensification of soybean production and extensive research on formulated soybean diets in aquaculture systems. [ABSTRACT FROM AUTHOR]

The effect of different concentrations of Chromolaena odorata (Siam weed) supplementation in fish feed on Clarias gariepinus fingerling growth characteristics was examined. Fish were randomly assigned to one of the four experimental groups: 0.0 percent (controls), 0.5 percent, 1.0 percent, and 3.0 percent concentrations of Chromolaena odorata in feed. Fish was fed at 5 percent body weight (g) per day for 70 days. Results showed that fish-fed the treatment diet had no significant effect on weight gain. The final body lengths (cm) of all treated groups were marginally (P > 0.05) different from the control group after 70 days. When the growth parameters were considered, the fish fed the diet containing 1.0 percent Chromolaena odorata had the best growth response (2.4±0.04g) while the fish fed the control diet had the slowest growth (1.2±0.13g). In comparison with the control fish fed the diet containing 1.0 percent Chromolaena odorata had the best feed conversion ratio (FCR), specific growth rate (SGR), and condition factor (K) This study showed that the inclusion of Chromolaena odorata in fish food at 0.5 - 3.0 percent level did not significantly increase the weight and length of catfish. [ABSTRACT FROM AUTHOR]

The technical efficiency of the African catfish production in Nigeria was assessed. A total of 609 farms were sampled, and 1,118 operations were recorded covering both the pre-COVID and COVID periods. A translog stochastic frontier modeling approach was used to simultaneously assess the technical efficiencies and the determinants of technical inefficiency of the catfish farmers. The mean technical efficiency for the catfish production in Nigeria is 85.4% indicating a scope of increasing production by 14.6% given the current technological state, which could contribute an additional 42,273 metric tons of fish to Nigeria's aquaculture. Comparative analysis showed that catfish producers during the COVID-19 period and producers from the Southern region were more technically efficient. The effect of management-dependent determinants is presented. Beyond management approaches, technical efficiency is seen to be improved significantly through the use of quality inputs. Based on these, measures for successful catfish production in Nigeria are recommended. [ABSTRACT FROM AUTHOR]

This study examined the cost efficiency of catfish production under different systems in Delta State, Nigeria. Primary data collected from 360 catfish farmers (comprising 121 concrete pond, 99 earthen pond and 140 plastic/tarpaulin pond systems) provided useful information for the data analysis. Descriptive statistics were used to describe the socioeconomic characteristics of the respondents. The stochastic cost frontier (SCF) approach was employed in analyzing the effi- ciency indices and their determinants. The results showed that the respondents were male dominated (64.44%), young and active, with the majority below 48 years of age. The majority of the respondents (76.67%) had a form of education that could boost their managerial abilities for catfish production. About 67.50% farmers were working full-time and 38.89% of them adopted the plastic/tarpaulin pond method because of ease of management. The average catfish weight produced was 1.50kg, and the average price per kg of mature catfish sold was NGN ₦ 722.77, with an average cost efficiency of 0.70. The study concludes that catfish production under different production systems is a cost efficient and economically viable venture, with the earthen pond method the most cost ef- ficient (0.72). The study therefore recommends that the causes of inefficiencies should be considered and addressed so as to enhance the efficiency of catfish farmers. [ABSTRACT FROM AUTHOR]

Background: Water pollutants cause adverse effects in aquatic ecosystems. The immunomodulatory and mitigating effects of dietary 1,3-glucan on fipronil and lead-induced intoxication in African catfish (Clarias gariepinus) were investigated. Two hundred forty catfish were randomly divided into four equal groups: those in the first group were fed basic diet and served as controls; those in the second group were supplemented with β-1,3-glucan (0.1%); those in the third group were exposed to combination of lead nitrate at 0.041 mg/L (1/10 96 h LC50) and fipronil at 2.8 mg/l (1/10 96 h LC50); and those in the fourth group were exposed to combination of fipronil, lead, and β-1,3-glucan. The health status, haematological, immunological, and histological changes were all evaluated. Result: Swelling on the dorsolateral side, spinal column deviation, sluggish movement, skin bleaching, excessive mucus secretion, significant variations in blood indices-related measures, and a 45% death rate were observed in the third group. There was a significant reduction in interleukin-1 (IL-1) and interleukin-6 (IL-6) and immunoglobulin M (IgM) concentrations, as well as decrease in their corresponding gene expression, indicating that fipronil and lead had immunosuppressive activity. Severe catarrhal enteritis and mucinous degeneration of the lining epithelium, and notable depletion of white pulp, congested red pulp and hemosiderosis were common pathological findings in the spleen. β-1,3-glucan alone or in combination with fipronil and lead provoked physical activity, blood indices, with elevations in IL-1β, IL-2, IL-6, and IgM concentrations, as well as up-regulation in their genes' expression in splenic tissues, when compared to the third group. The spleen and intestine had normal histological architecture with 5% mortalities. There were no fish deaths in the β-1,3-glucan-alone or control groups. Conclusion: The use of β-1,3-glucan (0.1%) as dietary supplement could be implemented to protect against the toxic effects of fipronil and lead toxicity by improving the health and immunological parameters of intoxicated catfish. [ABSTRACT FROM AUTHOR]

Artificial light in various spectral is a relatively new development for modifying the environment of fish. According to research, light has a spectral and species-specific effect on fish.. As a result, the goal of this study was to see how different visible light colors affected Clarias gariepinus growth and digestive enzymes. 105 Juvenile fish (body length 10.00 ± 0.55 cm, initial weight 8.67 ± 0.62 g) were randomly exposed in triplicate to the following LEDs: Red (RL), Blue (BL), Green (GL), and Yellow (Y). Total Darkness (TD) and Ambient Light (AL) were used as controls. The fish were exposed for 12 hours overnight for 50 days. At five-day intervals, the fish's body weights were measured with an electric weighing scale (0.01g sensitivity); head length (cm), tail length (cm), and total body length (cm) were measured with a graduated measuring plastic box. The variables listed below were computed: Weight Gain (WG), Daily Weight Gain (DWG), Daily Growth Rate (DGR), Specific Growth Rate (SGR), Percentage Weight Gain (PWG), Food Conversion Ratio (FCR), Length Gain (LG), Daily Length Gain (DLG), Survival Rate (SR) and Condition Factor are some of the metrics used to calculate weight gain. Standard methods were used to measure the activities of digestive enzymes (proteinase and amylase). ANOVA was used to compare the acquired means, and Duncan's multiple range tests were used to further separate the means. Fish reared in YL had significantly higher WG, DWG, DGR, PWG, DLG, LG, and CF levels. SR of fish reared under TD conditions was the lowest, but it was significantly (P < 0.05) higher in fish reared under YL and RL conditions. Fish exposed to YL had significantly higher FCR and CF than those exposed to the other light treatments and the Control. The digestive enzyme activities were significantly (P < 0.05) reduced during the light treatment. Finally, nighttime artificial light exposure had a significant impact on juvenile catfish growth performance and digestive enzymes, with yellow light eliciting better growth performance. [ABSTRACT FROM AUTHOR]

Our study helps to evaluate the immune response, antioxidative status, and resistance against heat stress (HS) in Clarias gariepinus treated with propolis extraction; the results will contribute to theories of fish physiology and immunity under high-temperature conditions. Forty-five fish were divided into three equal groups: the control, the HS group at 36 °C, and the HS treated with alcoholic extraction of propolis that dissolved in water for 3 weeks. The results of our study suggested that the stress response differs among tissues thymus, spleen, and liver. All the tissues showed alteration in morphological and cytological structure at the light microscope (LM) and transmission electron microscope (TEM); thymus showed edema and thymocyte destruction; the spleen detected collagen deposition, and the liver displayed endoplasmic reticulum amplification (ER). In addition, we examined oxidative stress and antioxidant defenses (lipid peroxidation, catalase, and glutathione) of the spleen and measured blood biochemical parameters (alanine transaminase and aspartic transaminase levels) after heat stress. However, this toxic effect of HS was neutralized by the propolis extraction. To conclude, propolis is recommended to cope with the impacts of heat stress on catfish (Clarias gariepinus) by improving immunity and antioxidative resistance. [ABSTRACT FROM AUTHOR]

Aquaponics with bio-floc can potentially offer sustainable food production with zero waste as it allows farming plants and fish simultaneously, whereby the former use fish waste as their nutrient sources, while the latter receives cleaner water from the plants in a closedloop system. In the aquaponics system, additional nutrients are usually added to support optimal plant growth, but it is suggested that the amount of such chemical nutrients should be controlled to prevent any harm to the fish. Furthermore, the plant and fish growth rates are influenced by the nutrients and the culture media used. This study aims to examine the effect of nutrition (full-nutrient and half-nutrient treatments) and different types of culture mediums (rockwool, rockwool-perlite, and rockwool-husk) on the growth rates of pak choi (Brassica rapa) and catfish (Clarias gariepinus) using split-plot design. Findings show that the half-nutrient treatment yielded a 17.12% higher plant growth rate and 23.87% heavier catfish weight than the full-nutrient treatment, but these treatments did not affect the fish survival rate. It was also observed that using different culture mediums did not result in any significant difference. [ABSTRACT FROM AUTHOR]

Using weight as a measure of size in cannibalistic species can be misleading. This research determined the growth pattern, cannibalism and heterosis of crosses between two African catfishes Clarias gariepinus (Cl) and Heterobranchus longifilis (Ht). Fry were reared communally for ClxCl, ClxHt, HtxCl and HtxHt for 14 days before triplicates of 100 fry were randomly stocked in concrete ponds. The length of the samples was taken weekly, and growth shooters were sorted out using the criteria of cut-off length earlier proposed by the authors. The Gompertz model successfully converged for the growth modelling of three crosses: ClxCl, ClxHt and HtxCl with asymptotic values of 40.44 mm, 59.42 mm, 57.27 mm. In contrast, the cross HtxHt converged using the monomolecular growth model with an asymptotic length of 72.09 mm. Type I and type II cannibalism were observed with a greater influence of H. longifilis. Absolute growth rate (AGR) was highest in HtxCl (1.52 mm.day-1) progeny and lowest in HtxHt (1.02 mm.day-1). There was positive heterosis for length and AGR with negative heterosis for survival (-8.93%) and sorting (-1.86%). There was positive heterosis for cannibalism. The study revealed the maximum length attainable for offspring of these crosses and sorting effectiveness/criteria. [ABSTRACT FROM AUTHOR]

There were two stocking densities (i.e. 9,000 and 12,000 larvae m−2), two doses of 17β-estradiol and control without any hormonal treatment i.e. 0, 2.5, and 5 mg L−1. Hormone were given by immersing larvae in water for six hours to reduce cannibalism in African catfish larvae. Fishes were reared for 14 days intensively. The highest fish survival was at a stocking density of 12,000 larvae m−2 with 2.5 mg L−1 17β-estradiol. Cannibalism decreased at higher densities compared to the control. The level of 17β-estradiol in treated fish tended to be higher than that of the control group but the coefficient of variance decreased. At the end of rearing, the use of 17β-estradiol at higher densities improved the specific growth rate and relative body length. [ABSTRACT FROM AUTHOR]

A 45-day feeding trial was conducted to study the effects of Safmannan as a feed additive for African catfish (Clarias gariepinus) fingerlings. A total of 270 catfish fingerlings were randomly distributed into nine experimental aquaria. Three complete diets were used in this study: Diet 1, a premium catfish feed in the market (feed type A); commercial catfish feed (feed type B) containing no added Safmannan (Diet 2), and 800 ppm of Safmannan (Diet 3). The results showed that fish growth was not significantly (P > 0.05) affected by diets. The feed conversion ratio of catfish fed with Diet 1 was not significantly different (P > 0.05) from catfish fed with Diet 3, reflecting the competitiveness of Safmannan-supplemented feed to the control feed. Interestingly, Safmannan supplementation significantly lowered (P > 0.05) the colony forming unit count and increased serum lysozyme activity. In conclusion, Safmannan could be used as an immunostimulant for catfish farming. [ABSTRACT FROM AUTHOR]

In the experiments, defatted black soldier fly meal reared on vegetable byproducts was used in the fry rearing of two economically important fish species, African catfish and rainbow trout. Both fish species were reared in a recirculation system and 0–33–66–100% of the complex fry feed was replaced by a defatted prepupae meal of black soldier flies during a 28-day feeding experiment. African catfish was reared at 25 ± 1 °C while rainbow trout was reared at 12 ± 1 °C. The results showed that the growth of African catfish was not significantly reduced when 66% of the feed was replaced by soldier fly meal (mean weight in the control fish group at the end of the experiment was 0.4632 ± 0.2469 g, while the 66% group resulted mean weights of 0.4150 ± 0.1886 g) and the survival did not show any statistically different results (mean survival in control group was 57.48 ± 13.76% while it was 56.6 ± 7.763% in the 66% group). In the case of rainbow trout, replacing the feed entirely with insect meal did not cause a decrease in weight gain (final mean weight in the control group was measured at 1.9640 ± 0.4154 g, while in the group consuming only insect meal, it was 1.9410 ± 0.4248 g) or in survival (in the control group 98.5%, while in the group consuming only insect meal 99.5%). All these preliminary results indicate that black soldier fly meal can be used directly as a nursery feed in fish farming as a partial or total replacement of complete feeds. The results showed that black soldier fly meal could replace 66% of the complex brood feed of African catfish and up to 100% of rainbow trout feed without deterioration of production results. Our experiments have therefore opened the way for further experiments on insect meal in larval rearing. [ABSTRACT FROM AUTHOR]

The increasing demand for livestock and poultry feeds results in the lack of fish meals (FM). Poultry slaughterhouse by-product (PSB) is one promising strategy due to its high protein content despite the limited content of lysine. Thus, supplementing lysine in dietary fish feed is necessary. The present study aimed to investigate how different lysine doses in feed with PSB and FM as animal protein sources affected protein digestibility, feed utilization, growth, hematology, and body composition of Sangkuriang catfish (Clarias gariepinus var. Sangkuriang). Sangkuriang catfish at the grow-out stage (15.54±0.17 g/fish) were used. The fish were fed six experimental diets with similar protein and energy content but different lysine levels at 1.25%, 1.75%, 2.25%, 2.75%, 3.25%, and 3.75%/kg (treatments 1 to 6). The addition of lysine to feed had a significant (P<0.05) effect on protein digestibility (ADCp), efficiency of feed utilization (EFU), and relative growth rate (RGR) of Sangkuriang catfish at a grow-out stage but had no significant (P>0.05) effect on survival rate, hematology, and nutrient content. The optimal doses of dietary lysine with PSB and FM to improve ADCp, EFU, and RGR of Sangkuriang catfish were 2.59%, 2.63%, and 2.62%/kg diet, respectively. However, the supplementation of PSB in experimental diets had no significant effect on glucose, triglyceride, total protein, urea, calcium, magnesium, albumin, globulin, hemoglobin, hematocrit, phosphorous, and mean corpuscular hemoglobin concentration (MCHC). The lysine addition in feed formulated with PSB and FM could improve the growth performance and increase the feed digestibility of Sangkuriang catfish at the grow-out stage. [ABSTRACT FROM AUTHOR]

Parasitic infestation has a serious impact on fish health causing severe economic losses in fish farming as well as it has public health importance. This investigation was conducted on the prevalence of diagenetic encysted metacercariae (EMC) and its histopathological alterations in some freshwater fishes sampled from El - Riah El-Tawfiki, Qaliobia Governorate, Egypt. In this regard, a total of 600 randomly collected fish comprising 400 Nile tilapia (Oreochromis niloticus), and 200 African catfish (Clarias gariepinus) were examined macroscopically and microscopically from December 2020 to September 2021. The infested fishes showed white to yellowish cysts/nodules of variable size in different organs. The recorded EMC was identified as Clinstomum sp., Euclinostomum sp., Haplorichiaed sp., Pygidiopsisgeneta spp. Cyanodiplostomum spp, and Prohemistomulum spp. in the Nile tilapia and Prohestomatide spp. in African catfish. The overall prevalence of EMC was 29.25% in Nile tilapia and 22% in African catfish. The highest seasonal prevalence of EMC was 43% in summer for Nile tilapia and 34% in winter for African catfish. kidneys of Nile tilapia and musculature of African catfish recorded the highest tissue distribution of overall recorded EMC. Severe histopathological changes were observed in fish organs including gills, subcutaneous musculature, kidneys, liver, and ovaries. In conclusion, these results reflect the negative impacts of EMC on fish reproduction and general health status, therefore awareness about the control of fish parasites especially in natural resources should be conducted. [ABSTRACT FROM AUTHOR]

Phytomedicines are affordable, safe, and offer great potential for treating and controlling wounds. The effects of herbal supplements on C. gariepinus wound healing were investigated. Twenty-four fish (146.4±0.74g) randomized into four paired sub-groups: G1 and G2, G3 and G4, G5 and G6, G7, and G8 were fed formulated rations containing no herbal additive (0.0g/kg), 5.0g/kg of Allium sativum, 10.0g/kg of Chromolaena odorata and 10.0g/kg of Talinum triangulare as feed additive respectively at 5% body weight. On the 21st day, a sterile incision measuring 45.0 mm by 1.0 mm was made on the dorsolateral side of each fish. Subgroups G2, G4, G6, and G8 were intraperitoneally inoculated with 0.1 ml of pathogenic Pseudomonas aeruginosa that had been predetermined (1.4 x106 bacteria/ml), while G1, G3, G5, and G7 were not inoculated. Post-incision, macroscopic parameters (measurements), given as percentage healing rates on days 3, 6, 9, 12, and 15, were used to evaluate the wound closure. Data were analyzed using descriptive statistics and ANOVA at α0.05. On day 3, there were significant differences between the control and treatment groups in the healing pattern (P < 0.05). On day 15 post-incision, G7 had the best healing rate in both inoculated (86.7 percent) and uninoculated (100 percent) fish, while G1 had the lowest healing rate (0.0 percent) and maximum healing rate (64.4 percent), respectively. The findings indicated that T. triangulare at a concentration of 10.0 g/kg was the optimum feed additive for promoting wound healing in C. gariepinus. [ABSTRACT FROM AUTHOR]

African catfish (Clarias gariepinus) is a promising food fish species with significant potential and growing mass of production in freshwater aquaculture. Male African catfish possess improved production characteristics over females, therefore the use of monosex populations could be advantageous for aquaculture production. However, our knowledge about the sex determination mechanism of this species is still limited and controversial. A previously isolated male-specific DNA marker (CgaY1) was validated using offspring groups from targeted crosses (n = 630) and it was found to predict the sex of 608 individuals correctly (96.43% accuracy). Using the proportion of recombinants, we estimated the average genetic distance between the potential sex determination locus and the sex-specific marker to be 3.57 cM. As an earlier study suggested that both XX/XY and ZZ/ZW systems coexist in this species, we tested the applicability of their putative 'moderately sex-linked loci' and found that no sex-specific amplification could be detected for any of them. In addition, temperature-induced masculinization suggested by others was also tested, but no such effect was detected in our stocks when the published parameters were used for heat treatment. Altogether, our results support an exclusive XX/XY sex determination system in our African catfish stock and indicate a good potential for the future use of this male-specific DNA marker in research and commercial production. • Validation of a male-specific marker confirms XX/XY-type sex determination in Hungarian strains of African catfish. • Strong linkage was detected between the male-specific CgaY1 marker and the sex determination region. • Temperature-induced masculinization at 36 °C between 5-8, 7–10 or 9–12 dph failed. • Validation of others' 'moderately sex-associated' DNA markers is failed, suggesting no ZZ/ZW system in these strains. [ABSTRACT FROM AUTHOR]

The freshwater mussel (Lamellidens marginalis) was employed with a 28-day aquarium rearing of stinging catfish (Heteropneustes fossilis) exposed to a sublethal concentration (0.75 mg/l) of Pb(NO3)2 to evaluate the growth, Pb bioaccumulation, and associated liver histopathology in fish. Three treatments (T2, T3, and T4) and a control (T1) were assigned with 20 fish and 5, 20, 40, and 0 numbers of mussel each. The specific growth rate, percentage of weight, and length gain showed a larger increase of Pb in T3 and T4 than in the control and T2. After 28 days, the highest amount of muscular and hepatic Pb was recorded as 2.43 ± 0.01 mg/L and 7.79 ± 0.8 mg/L respectively in the control group (T1); the lowest amount was recorded in T4 as 0.46 ± 0.07 mg/L and 4.41 ± 0.58 mg/L respectively. Liver histopathology exhibited vacuolization, raptured hepatocytes, blood congestion, necrosis, and fat droplets accumulation in different intensities. The control group manifested severe pathology; the T4 treatment exhibited comparatively low signs. [ABSTRACT FROM AUTHOR]

This study aims to monitor physico-chemical parameters and heavy metal (HM) levels in the water, HM levels, and haemato-biochemical changes in parasite-infected and non-infected catfish, Clarias gariepinus, in wild and cultivated origins. The outcomes of physico-chemical properties and heavy metal (HM) levels in water revealed significant variations between the two selected sites, except for cadmium metal (p< 0.05). HM concentrations in both water and organs of the two catfish origins decreased as the following decreased: Fe < Zn < Pb < Cu < As < Cd. Furthermore, the concentration of vital HM was significantly lower in wild catfish as compared to cultivated catfish, whereas non-vital HM was significantly higher in wild catfish. However, the HM accumulation in the different organs of catfish is ranked in ascending order: liver > gills > intestine > muscles. The hematological and biochemical investigations revealed a significant decline in the hemoglobin value, packed cell volume, number of red blood cells, albumin, total protein, and globulin while total aspartate aminotransferase activity, white blood cell count, alanine aminotransferase activity, glucose, and urea levels were all significantly higher in parasitic-infected catfish from two origins compared to uninfected catfish. Human health hazards, as evaluated by non-carcinogenic risk (hazard index and target hazard quotient), estimated daily intake, and carcinogenic risk, were all below the benchmark's allowable range. Nonetheless, the outcome of the health risk assessment suggests that consumption of the muscles of catfish from wild and cultivated origins cannot pose considerable health risks for children and adult consumers. Additionally, the prevalence of parasites can be used as a surrogate indicator to predict the possible impact of metal pollution and bioaccumulation. Consequently, this study suggests that Egypt's environmental management conducts routine HM monitoring in the studied sites to reduce potential health risks. [ABSTRACT FROM AUTHOR]

Fluazifop-P-butyl is a commercial herbicide commonly used in agricultural practices for controlling grass weeds. The present work aimed to detect and compare the deleterious changes that may occur in the kidney of the African catfish, C. gariepinus under the different concentrations of fluazifop-P-butyl, as well as studying the histopathological changes in the kidney of exposed fishes to different levels of the selected pollutant. Fish were exposed to different concentrations (1.72 & 0.57 mg/L) of fluazifop-P-butyl for different periods (14 and 28 days). At the end of the exposure time, the levels of uric acid, creatinine and urea were measured in the blood serum to determine kidney functions. In addition, a histopathological examination of the kidney was performed to assess the impact of fluazifop-P-butyl on its tissue structure. The results showed that exposure of catfish Clarias gariepinus to fluazifop-P-butyl led to a significant increase in the levels of uric acid, creatinine, and urea in the serum, indicating impairment in kidney functions. The histological examination revealed pathological changes in the kidney structure, including degeneration of renal cells, atrophy of renal tubules and interstitial fibrosis. The findings of this study highlighted the importance of considering the potentially toxic effects of fluazifop-P-butyl on aquatic organisms upon using this herbicide in agricultural practices. [ABSTRACT FROM AUTHOR]

Background: A study was conducted to evaluate the serum biochemical and oxidative stress parameters of catfish (Clarias gariepinus) obtained from homestead ponds in Makurdi metropolis, Nigeria, in order to establish changes due to stress from transportation, following the pretreatment of transporting water with palm oil and aqua anti-stress. Serum samples were obtained from the blood collected from the fish a day before, just before loading the fish, immediately after journey, and 3 days post-transportation. The samples were used to analyze for some oxidative stress markers like malon dialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and other biochemical parameters such as; alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total cholesterol (TC) and triglyceride (TRG). Results: There was a significant (p<0.05) increase in MDA levels of low dose palm oil-treated water (PA) group compared with the control (C) just before journey, while there was no significant (p>0.05) difference in MDA levels of PA group compared with the control after the journey. However, there was no significant (p>0.05) difference in the MDA levels of aqua antistress agent-treated water (A) group compared with the control, before the journey and after the journey. There was a significantly (P<0.05) elevated activities of ALT, AST and ALP in palm oilpretreated water (PA and PB) groups when compared with the control, just before the journey and immediately after the journey. However, there was no significant (p>0.05) difference in the ALT, AST and ALP activities of aqua anti-stress agent-treated water (A) group when compared with the control, before the journey and after the journey. There was no significant (p>0.05) difference in the TC and TRG levels of A, PA and PB groups when compared with the control group, before the journey and after the journey. The ALT, AST and ALP activities of the fish transported in water treated with palm oil were markedly reduced at the end of the journey when compared with the levels just before the journey. Conclusion: The findings of this study have shown that both aqua anti-stress agent and palm oil may improve the biochemical parameters of African catfish, which enhanced their responses to stress during the eight hour journey but the conventional anti-stress agent was more effective than palm oil. [ABSTRACT FROM AUTHOR]

Introduction: The distribution and prevalence of gastrointestinal helminths in African catfish (Clarias gariepinus) from Ajiwa reservoir, Katsina State, Nigeria was investigated between March and August 2021, to understand the health status of the fish, potential risk to their existence and safety of consumption of fish from the water body. Methods: A total of 162 live African catfish species were collected from artisanal fishermen from three major landing sites on the reservoir. The fish were identified and separated based on sex before being transferred live to the Fish Biology laboratory, Federal University Dutsin-Ma, Katsina State for further evaluation. The fish were dissected and the guts were removed for examination of the gastrointestinal helminths. Results: A total of 149 helminths were collected from the 132 infected fish. The helminths belong to nematode and cestode groups with nematode dominating with three species and 59.06% abundance. Capillaria species, a nematode was the dominant species representing 29.53% of the helminths from the water body. A higher amount (57.72%) of the helminths were recovered from the intestine. The prevalence of the parasitic worms was affected by sex (p=0.001) with females having a higher prevalence (91.76%). There was no significant difference due to the sampling location (p=0.076) and length of the fish (p=0.298). However, weight showed a significant association with the prevalence (p=0.019) and the prevalence decreased with an increase in the size of the fish. Significance: Although the distribution and abundance of the gastrointestinal helminths in the Ajiwa reservoir can be said to be low relative to the number of fish examined, however, the prevalence is high and something of concern. Sex and weight are important factors strongly associated with the prevalence of parasitic helminths in the reservoir. [ABSTRACT FROM AUTHOR]

Introduction: Cryptosporidiosis is recognized as a significant water/food-borne zoonosis associated with morbidity and economic losses in farm animals. The zoonotic risk of Cryptosporidium via fish-borne infection is emerging as a significant public health concern worldwide. Aim: This study investigated the incidence of Cryptosporidium oocysts among Catfish (Clarias gariepinus) sold for human consumption at major wet markets in Maiduguri metropolis, Borno State. Methods: A cross-sectional survey was conducted from January to April 2015 to select and sample 200 catfish from Custom market (n=100) and Monday market (n=100) of Maiduguri metropolis council. The fishes were dissected to collect visceral contents. The intestinal mucosal scrapings were used to make smears, which were subsequently fixed with Bunsen flame and stained with Ziehl-Nielsen Acid-fast stain for the detection of Cryptosporidium oocysts under oil immersion. Results: In total, 3 (1.5%; 95%CI = 0.39-4.68) samples were positive for Cryptosporidium oocysts. Female fish had a non-significantly (χ² test: p>0.05) higher sex-specific prevalence of 1.92% (95% CI = 0.33-7.45) compared with males 1.04% (95% CI = 0.05-6.49). Cryptosporidium oocysts were only recorded in adult fishes (1.62%; 95% CI = 0.42-5.04) and catfishes collected from Custom Market had a slightly high but non-significant (χ² test: p>0.05) prevalence of 2.0% (95% CI = 0.35 - 7.74) compared to those from the Monday Market (1.0%; 95% CI = 0.05 - 6.24). Significance: The presence of Cryptosporidium oocysts in catfish sold for human consumption in Maiduguri and its environs highlights the potential role of fish as a source of human infection, especially among people who frequently consume roasted or improperly cooked fish. [ABSTRACT FROM AUTHOR]

The present study investigated the effects of dietary supplementation of nanocurcumin (NCur = 150 ppm) in African catfish feed for 15 days along with two doses of florfenicol—a therapeutic dose (FFC1 = 10 mg/kg.BW) and a high dose (FFC2 = 30 mg/kg.BW). Serum biochemical parameters and histopathological changes in liver and kidney tissues were determined post-feeding. Additionally, fish were experimentally challenged with a virulent strain of Aeromonas veronii to explore the fish's capacity to resist infections. Results indicated that the serum level of total protein was significantly elevated in the FFC2 + Ncur group compared with control, Ncur, and FFC2 groups. Total protein level was also higher in FFC1 + Ncur compared with that of the FFC1 group. Moreover, feeding NCur, FFC1 + Ncur, and FFC2 + Ncur resulted in a significant increase in globulin levels compared to control, FFC1, and FFC2-Fed groups. However, the albumin level was unaffected. Serum levels of AST, ALT, ALP, and urea significantly increased in FFC2-fed fish compared to controls indicating liver damage. The higher dosage of FFC2 induced histological alterations in the liver and kidney architecture, represented by a rupture of the central vein, cytoplasmic vacuolation, hepatocytes necrosis, and severe inflammation. Surprisingly, NCur inclusion improved most of the altered biochemical parameters and mitigated FFC-induced histological damage in the hepatic and renal tissues. Similarly, fish that were fed a combination of both FFC and Ncur showed a higher resistance when exposed to A. veronii infection, as the mortality rates were significantly lower than those of the control group. Our findings indicated that incorporating NCur into the diet can have multiple benefits for the sustainable aquaculture of African catfish. These advantages encompass mitigating drug-induced damage to the liver and kidney tissues, augmenting the therapeutic efficacy of FFC in a synergistic manner and providing protection against A. veronii infections. [ABSTRACT FROM AUTHOR]

Simple Summary: The study evaluates the hybridizations in two African catfish, i.e., C. gariepinus and C. macromystax, using artificial reproduction. Reproductive and growth performance were evaluated. The results indicated that both species possess a similar gonadosomatic index. The parent C. gariepinus possesses higher male reproductive quality than C. macromystax. Fecundity was higher in the female parent of C. macromystax and lower in the C. gariepinus species. The highest fertilization rates and hatching rates were achieved in the hybrid cross of C. macromystax × C. gariepinus, which also recorded the lowest deformed larvae. Survival rates at the larval stage were more than 80% with the highest record of survival in the hybrid C. macromystax × C. gariepinus. However, survival rates in the fry stage were lower than 70%. The hybrid cross (C. macromystax × C. gariepinus) showed the best growth performance, which was similar to the parental cross (C. gariepinus × C. gariepinus). The study revealed the potentials of the hybrid C. macromystax × C. gariepinus, and hybridizations of C. macromystax × C. gariepinus (Cm × Cg) are indeed possible and proved to have better growth and survival rate under semi-arid conditions, which would contribute significantly to the improvement of C. macromystax production in captivity. The study evaluates the hybridizations between two African catfish, C. gariepinus and C. macromystax, using artificial reproduction. Fecundity and gonadosomatic index were assessed, and growth performance at different developmental stages was evaluated. The results indicated that both species possess a similar gonadosomatic index. The parent C. gariepinus possesses significantly (p < 0.05) higher male reproductive quality than C. macromystax. Fecundity was significantly higher (p < 0.05) in the female parent of C. macromystax and lower in C. gariepinus. The highest fertilization rates and hatching rates were achieved in the hybrid cross of ♀C. macromystax × ♂C. gariepinus (♀Cm × ♂Cg) which also recorded the lowest deformed larva rate. Survival rates at the larval stage were more than 80%, with the highest record of survival in the hybrid ♀Cm × ♂Cg. However, survival rates in the fry stage were lower than 70%. The hybrid cross (C. macromystax × C. gariepinus) outperformed the parental cross of C. macromystax but was not significantly similar to the parental cross of C. gariepinus. The study revealed the potential of the hybrid ♀C. macromystax × ♂C. gariepinus, and hybridizations of ♀C. macromystax × ♂C. gariepinus (♀Cm × ♂Cg) are indeed possible and proved to have a better growth and survival rate under semi-arid conditions, which would contribute significantly to the improvement of C. macromystax production in captivity. [ABSTRACT FROM AUTHOR]

This experiment investigated the impact of two water sources and their quality on the survival, growth, and health of Clarias gariepinus fingerlings reared in indoor concrete tanks. 400 fingerlings of mean weight 15.33±3.47 g and total length 12.63±1.00 cm (mean ± standard deviation) were randomly distributed into four concrete tanks of 12 m3 capacity each. Water quality was analyzed bi-weekly throughout the study duration. Growth parameters such as mean weight gain (MWG), specific growth rate (SGR), and feed conversion rate (FCR) were calculated using standard procedures. At study termination, duplicate groups per treatment were assessed for survival rate and a health status check was determined by a hematological evaluation and microscopic examination of parasitic incidence. Results indicated that fish reared in water sourced from a bore-hole [BH] performed comparatively significantly better in growth (p < 0.05) than fish in water from an earthen pond [EP] as the MWG stood at 294.05±79.17 g for the former against 211.03±54.62 g for the latter with the survival rates for both treatments being in excess of 90%. Additionally, fish reared in EP presented with a higher infestation load of Trichodina spp., although there was no significant difference (U = 7, p > 0.05) between fish reared in EP and BH treatments with regards to their packed cell volume levels and white blood cells. The outcome of this study shed light on the impact a water source can have on the growth and health status of C. gariepinus with a recommendation for microbiological analysis of water supply from open/surface systems before usage for the African catfish aquaculture. [ABSTRACT FROM AUTHOR]

Sangkuriang catfish (Clarias gariepinus) is one of the aquaculture commodities with great potential to be developed in Indonesia to support the demand for feed. Efforts to reduce dependence on imported feed raw materials for fish feed is continued. Water hyacinth (Eichhornia crasspies) leaf which contains phytochemical compounds such as flavonoids, tannins, steroids and saponins is an alternative raw material for fish pellet component. This study aimed to determine the addition of fermented water hyacinth leaf meal in fish feed on the growth, survival rate, and blood profile of sangkuriang catfish. In total 150 fish (average initial weight 5.45 ± 0.02 g) were randomly divided into triplicates of five groups, containing 10 fishes per group. Group one is a control group, P1 (10% of non-fermented water hyacinth leaf meal), while P2, P3 and P4 were treatment groups of fish fed with 10, 15, and 20% fermented water hyacinth leaf meal by Aspergillus niger. At the end of the 42 days of treatment, growth, survival rate, and blood profile of all fish were determined. The results showed that the addition of 10% water hyacinth leaf meal fermented by A. niger had an effect on the growth of final weight, body weight gain and specific growth rate (p < 0.05) in comparison to all groups. However, the addition of any concentration of water hyacinth leaf meal did not affect on the feed conversion ratio and survival rate value. Further, the addition of water hyacinth leaf meal had a significant effect (p < 0.05) on the erythrocytes, leukocytes and hemoglobin of fish, but did not show a significant effect on the values of hematocrit and platelets. It is concluded that addition of the fermented 10% water hyacinth leaf meal in the feed has beneficial to improve the growth of sangkuriang catfish. [ABSTRACT FROM AUTHOR]

The airbreathing walking catfish (Clariidae: Clarias) comprises 32 species that are endemic to African freshwater systems. The species-level identification of this group is challenging due to their complex taxonomy and polymorphism. Prior to this study, the biological and ecological studies were restricted to a single species, Clarias gariepinus, resulting in a biased view of their genetic diversity in African waters. Here, we generated the 63-mitochondrial Cytochrome c oxidase subunit 1 (COI) gene sequences of Clarias camerunensis and Clarias gariepinus from the Nyong River in Cameroon. Both C. camerunensis and C. gariepinus species maintained adequate intra-species (2.7% and 2.31%) and inter-species (6.9% to 16.8% and 11.4% to 15.1%) genetic distances with other Clarias congeners distributed in African and Asian/Southeast Asian drainages. The mtCOI sequences revealed 13 and 20 unique haplotypes of C. camerunensis and C. gariepinus, respectively. The TCS networks revealed distinct haplotypes of C. camerunensis and shared haplotypes of C. gariepinus in African waters. The multiple species delimitation approaches (ABGD and PTP) revealed a total of 20 and 22 molecular operational taxonomic units (MOTUs), respectively. Among the two Clarias species examined, we found more than one MOTU in C. camerunensis, which is consistent with population structure and tree topology results. The phylogeny generated through Bayesian Inference analysis clearly separated C. camerunensis and C. gariepinus from other Clarias species with high posterior probability supports. The present study elucidates the occurrence of possible cryptic diversity and allopatric speciation of C. camerunensis in African drainages. Further, the present study confirms the reduced genetic diversity of C. gariepinus across its native and introduced range, which might have been induced by unscientific aquaculture practices. The study recommends a similar approach to the same and related species from different river basins to illuminate the true diversity of Clarias species in Africa and other countries. [ABSTRACT FROM AUTHOR]

Due to their nutritional value, alternative vegetable materials such as soybean are needed to promote sustainable aquaculture development. However, phytate in soybean could interfere with the protein digestion of the fish body. This study examines the effectiveness of phytate enzymes in enhancing protein digestibility, growth performance, mineral digestion, and body chemical composition of Sangkuriang catfish (Clarias gariepinus var. Sangkuriang) juveniles. The study was completely randomized design with 4 treatments and 3 repetitions. One hundred thirteen Sangkuriang catfish juveniles (7.65 ± 0.14 g) were used for each repetition. The fish were fed with an experimental diet supplemented with various doses of phytase enzyme: 0 (A), 500 (B), 1,000 (C), and 1,500 (D) FTU/kg of feed. The mineral digestibility, protein digestibility, protein efficiency ratio (PER), feed conversion ratio (FCR), the efficiency of feed utilization (EFU), apparent digestibility coefficients (ADCp), relative growth rate (RGR), and survival rate (SR) were observed. Data were analyzed using analysis of variance followed by Duncan's multiple range test. The results showed that adding 1,000 FTU/kg of phytase enzyme (C) exhibited the highest PER, FCR, EFU, ADCp, and RGR value of Sangkuriang catfish juveniles compared to other treatments. All treatment groups (B-C) had the same SR value (100%) and had the highest crude protein and ash content compared to the A group. All group treatments also exhibited a higher phosphorus, calcium, potassium, magnesium, iron, zinc, manganese, copper, and cobalt. Therefore, phytase enzyme supplementation could improve protein digestibility, mineral digestibility, growth performance, and body chemical composition of Sangkuriang catfish juveniles. [ABSTRACT FROM AUTHOR]