In Vivo antimicrobial activities of Allium cepa on cultured adult Clarias gariepinus (Burchell, 1822)

The design of the study was to evaluate the antimicrobial activity of Allium cepa in cultured Clarias gariepinus. The proximate compositions and Mineral assay of whole A. cepa bulb and experimental diets were determined using standard methods. Microbial susceptibility assay was carried out in vitro on Staphloccocus aureus and Escherichia coli using Agar well diffusion. Bacterial isolation and identification from the different treatments and control was carried out according to standard methods. High moisture content (89.25 %) was recorded followed by carbohydrate (9.45%) and crude protein (7.21%). Experimental and control diets revealed 50 % and above crude protein content. In vitro susceptibility test of the various onion extracts and antibiotic shows susceptibility of the reference strains to the onion extracts. Bacterial isolation and identification showed the presence of pathogenic gram positive and negative coli and bacilli respectively. Results obtained for total fungi counts show the presence of both systemic and superficial fungi. Lower bacteria and fungi counts were observed 14 days after the withdrawal of experimental diets. Conclusively, onion can be used as antimicrobial agent in the culture of Clarias gariepinus. &nbsp

Biology, digestive enzymes and organosomatic indices of Chrysichthys nigrodigitatus (Lacépède, 1803) from Oyan Dam, Southwestern Nigeria

Some aspects of the biology, digestive enzymes and organosomatic indices of Chrysichthys nigrodigitatus purchased from fishermen in Oyan dam was investigated. This study was aimed at providing information on the composition of food materials found in the gut and specific activities of selected enzymes as it affects the domestication of the species. 100 specimens of the species were examined for stomach contents, length-weight relationship, digestive enzyme assay and organosomatic indices, using standard methods. Food items observed were detritus (4%), fish part (12%), Insecta (13%). Sand was observed to be 11% of total stomach volume. The logarithmic equation for length-weight relationship lnW=2.68lnl-3.79 indicated that an increase in length led to a corresponding increase in weight with ‘R’ = 0.611, calculated ‘r’=0.78, ‘a’=2.68 and ‘b’=3.79 indicating positive allometric growth pattern. Amylase exhibited high activity in the stomach, while lipase and proteinase in the stomach and posterior intestine. Specific activities of digestive enzymes showed significant differences (p<0.05). Viscerosomatic (2.92± 0.25), hepatosomatic (2.27± 0.22) indices and Fulton condition factor (1.93± 0.06) were recorded. Feed items present in the species confirm its overlapping feeding habit, indicating that the species is an omnivorous detritivore. This was also depicted in the activities of the different digestive enzymes

Aflatoxin, bacterial and heavy metal load in Scomber scombrus and Clupea harengus from two selected coldroom facilities in Kwara State, Nigeria

Impurities found in fish have been a major cause of disease and illness to consumers. This study's objective was to evaluate the total aflatoxin, heavy metal and microbial load in two frozen fish: Scomber scombrus and Clupea harengus from two (2) cold room facilities in Omu-Aran and Ilorin. Heavy metals, aflatoxin and microbial load were investigated using standard methods. Health risk was also determined using health risk index (HRI), daily intake of metals (DIM), and health quotient (HQ), and total toxicity of metals (TTM). Cd, Cu, Ni, Pb, Mn and Cr did not differ significantly (p>0.05) in both species from both locations. Nickel was lower than the recommended limit by World Health Organization (WHO). Level of Mn and Cr were higher in both species. Mn load was higher in the muscles of the sampled fish than in the gills from September through to November with highest value of 1.26±0.08 and 1.30±0.12 obtained for S. scombrus and C. harengus. Highest concentrations of all metals was observed in the gills except manganese and copper [Cd = 0.03 (S. scombrus), Cr = 1.22±0.13 (S. scombrus), Ni = 0.025±0.04 (S. scombrus), Pb = 0.06±0.02 (S. scombrus)]. HRI was > 1 in the different age groups for the different metals. TTM was > 1 in both species. Total aflatoxin level was higher in the gills (4.25 – 5) ppb than in the muscle (1.5 - 3) ppb for both locations respectively. Vibrio spp. and non-coliform bacteria were high in both species from both locations. The study concludes that heavy metal loads (Mn, Cd, Cu, Cr, and Ni) were more than the permitted limitations imposed by FAO, WHO and EU legislation for fish and fish products placing consumers at health risk

Antioxidant activity and chemical composition of Clarias gariepinus from nature and captivity

Gradual shift from eating healthy to unhealthy food is a major contributor to development of noncommunicable diseases . This study compared the antioxidant activity and chemical composition of wild and cultured Clarias gariepinus. A total of 10 fish each were collected from both environments. Nutrient composition, antioxidant activity, fatty acid and heavy metals load of the samples were determined using standard methods. Significant difference was observed in the proximate composition (crude protein (CP), Ether Extract (EE) and Nitrogen free extract in both samples, with higher values of CP (54.98 ± 0.66%) and EE (34.17 ± 0.33%) observed in the wild sample. No significant difference was observed in the values for sodium, potassium, phosphorus, calcium, magnesium, zinc and iron. However, manganese (350.93 ppm) was significantly (P<0.05) higher in the cultured species. Scavenging activity against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) was not statistically different (P > 0.05) at 50 mg/ml concentration. Hydrogen peroxide radical scavenging activity was however low in cultured and wild samples (1.27 and 8.12 mg/100 g) respectively. Heavy metals level in both samples were not statistically different (P>0.05). It was concluded that the cultured C. gariepinus compared favourably with the wild species in their mineral composition, antioxidant activity, and heavy metal content as opposed to local belief

Heavy Metal Burden and Health Risk Assessment of Fresh, Frozen and Smoked Fish from a Local Market in Southwest Nigeria

Heavy metals load in fish environment and fish products had been an issue of public concern. The burden of some heavy metals in fresh tilapia (Oreochromis niloticus), frozen Herring (Clupea harengus), smoked herring, and associated risk to man was investigated. Atomic absorption spectrometry was used to determine metal concentrations. Standard risk measurement indices [daily metal intake (DMI), hazard quotient (HQ), and health risk index (HRI)] were used. Levels of Mn and Fe were significantly different (p<0.05) among the fish species, while the burden of other metals was low to not detected in the samples. The level of Cu (0.11±0.04), Zn (2.51±0.82), and Fe (8.72±4.41) were recorded in the bones of smoked herrings, while the highest levels of Mg were recorded in fresh tilapia. Gills recorded significantly (p<0.05) high levels of Mg (1.16±0.02), Fe (14.92±0.53), Cu (0.10±0.00), and Zn (1.35±0.04). The muscle of the frozen herring records the highest burden of these metals. Mn, Fe, Cu, and Cd revealed the highest HRI in all fish samples and age categories, especially for nine years old and below children. In conclusion, health fish indicators revealed that Mn, Fe, Cu, and Cd pose a risk to the populace and, with long time consumption, can do more damage to consumers, especially frozen herring

Antimicrobial potentials of mucus mucin from different species of giant African land snails on some typed culture pathogenic bacteria

The study aims at evaluating the antibacterial activities of mucus mucin from three species of the giant African land snails; Archachatina marginata, Achatina achatina, and Achatina fulica. Snail slime was collected from forty-five snails comprising the three species of snails from the southwestern region of Nigeria. The antibacterial potential and bacteria growth rate (in hours) of the mucus mucin were determined using agar well diffusion method and liquid broth. Acetic acid (acid), ammonium bicarbonate (alkaline), and water (aqueous) were each used to extract the slime. The result showed that mucus secretions from the three snail species differed in color, degree of the sliminess, and volume. Snail mucus extract had antimicrobial effects on gram-positive and gram-negative bacteria. The inhibitory effects of mucus extracts differed depending on the treatment method and storage time, with acid extracts having a higher inhibitory capacity regardless of snail species or storage time. A. marginata's mucus secretions had a stronger antibacterial activity against Bacillus subtilis when compared to mucus from A. achatina and A. fulica. The zone of inhibition of the mucus mucin in solid agar ranged between 24.0–19.5mm for A. marginata and ranged between 21.0-17.5mm and 21.0–15.0mm for A. achatina and A. fulica, within 2-72 storage hours). Mucus mucin seems to lose its antibacterial potential with time; however, the antibacterial capability of the giant African snail species could provide the much-needed solution to antibiotic resistance

Effeet of Whole Allium cepa Linn. on haematological and biochemical components of Clarias gariepinus Juveniles

Toxicity of onion (Allium cepa) bulb though documented for man and some livestock but few studies in fish. Onion bulb slurry was administered to Clarias gariepinus juveniles at 200,100,25g/kg and 5, 1.5, 0.4g/l through diets and bath. Cellular immune response, humoral changes, liver and kidney function and histopathology of some visceral organs were examined. Proximate composition of the bulb was determined. Onion bulb revealed presence of carbohydrate (7.82%), protein (4.48%), crude fiber (1.68%), iron (0.5mg/l), magnesium (210mg/l), flavonoids (0.46%), saponins (0.28%), tannins (0.95%). PCV, Hb, RBC and WBC were increased in all treatments but values were higher in bath treatment for RBC (3.0×1012/L), PCV (32.7%), Hb (10.7%). MCV, MCH and MCHC showed similar trend. Similar trends as in RBC and WBC were observed in total proteins. Liver and kidney functionality as expressed by ALT, AST, ALP, creatinine and BUN exhibited no damaging effect on organs. Degenerations were observed in the hepatocytes and epithelia cells in the kidney in some treatments especially in bath treatments. In conclusion, onion bulb showed no toxicity in the blood parameters but dose should be considered to avoid harmful effect on liver and kidneys

Assessment of fecundity of Brycinus macrolepidotus in Akomoje water reservoir, Abeokuta, South West, Nigeria

Overfishing and threat of extinction globally has been a topic of concern in the fisheries sub-sector over the years. This study assessed some aspect of the biology of Brycinus macrolepidotus in Akomoje reservoir, lower River Ogun, Nigeria. A total number of 838 fish specimens were collected bi-monthly for a nine month period from commercial catches using cast nets and long line. A total number of 51 mature female were selected for fecundity analysis which was limited to only sexually gravid female fish. Length and weight of experimental fish were measured. Data were subjected to analysis of variance (ANOVA), descriptive and inferential statistics. Correlation statistics was carried out to ascertain relationship between absolute and relative fecundity with length and weight of fish. Length and weight of experimental fish ranged between 14.5-39.4 cm and 938-1956 g. The relative fecundity ranged between 441 and 3,597 eggs with a mean of 1,702±0.16 eggs while absolute fecundity ranged from 5,838 to 39,208 eggs with a mean of 14,326±0.52 eggs. Strong positive relationship existed between total length and absolute fecundity (r= 0.74), and relative fecundity (r = 0.81). The reproductive potential of the species in this water body showed the ecological suitability of the species to its environments and to its thriving fisheries. The skewed sex ratio observed is an indication of threat to the species abundance in the lower River Ogun. Therefore, the habitat should be monitored towards sustainable methods of managing the stock in the reservoir

ENDO AND ECTO PARASITE PREVALENCE AND ABUNDANCE IN SOME FISH SPECIES FROM AKOMOJE, OGUN RIVER SOUTH-WEST NIGERIA

Parasites are the second most abundant microorganisms that infect and cause disease in wild and cultured fish after bacteria. The study investigated the parasite prevalence, abundance, mean intensity and dominance in some fresh water fish from Akomoje, Ogun River, Nigeria from February to May, 2016. Eight fish species were collected and identified to the species level. Experimental fish were measured and weighed. Endo- and ecto-parasites were examined for; from Skin/scale, dorsal and caudal fins, gills, intestine and stomach of fish. Water sample was collected from shore, mid and extreme of the landing site and also analysed for parasite abundance. Prevalence of parasite in all fish species varied slightly with size. Myxozoan group revealed the highest dominance of ecto- and endo-parasites in virtually all fish species while mean intensity and abundance of Myxozoan spp. was highest in Oreochromis niloticus and Hemichromis fasciatus. Highest case of a single species of ecto- and endo-parasite in a fish sample was that of Nematode larva in Chrysicthys nigrodigitatus (41.43 %) and Trichocerca sp. (Rotifera) in Mormyrus rume (52.9 %).Water analysis revealed three parasite groups that were present in the sampled fish. Conclusively, Akomoje landing site of Ogun River has a rich burden of parasites