Papers by Dr. Ozovehe Patrick Samuel
Journal of Fisheriessciences.com, 2021
The anthropogenic activities culminating in environmental pollution all over the world that usual... more The anthropogenic activities culminating in environmental pollution all over the world that usually leads to release of plethora of pollutants such as cadmium calls for concern. In the present study the effects of cadmium chloride on the production of antioxidants such as Malondialdehyde (MDA) in C. gariepinus and how such effects can be ameliorated through administration of vitamins were investigated. C. gariepinus fingerlings (whose initial weight ranged from 3-11 g) were exposed to sub-lethal concentrations of Cd (00, 12 mg/L, 16 mg/L, 20 mg/L and 24 mg/L) with replicate in each case. Minimum concentration of the toxicant was taken as the concentration for each of the vitamins and administered across all bud. Fresh concentrations of both toxicant and vitamins were administered every 72 hours for a period of 12 weeks every time the water medium was changed. The various treatments group include Cd (Cd only with T1-T4 and replicates), CdVA (Cd+vitamin A with T1-T4 and replicates), CdVC (Cd+vitamin C with T1-T4 and replicates) and CdVE (Cd+vitamin E with T1-T4 and replicates). 3 samples of the fish were randomly selected and sacrificed from each aquarium tank every 2 weeks of the exposure period. The gills, kidneys and liver were excised from these specimens and homogenized in sodium phosphate buffer. From the results: samples exposed to Cd only group, the MDA production levels in the liver were generally low. The T2 and T3 mean values in the 6 th and 10 th weeks of exposure, respectively are significantly higher than other treatments including the control. The control mean values in the 8 th week of exposure are significantly higher than other treatments. The highest mean value of MDA in the liver was 40.17 ± 0.05 nM/mg obtained in T3 at the end of the 2 nd week of exposure. In the kidney, the control mean values in the 2 nd , 4 th , 8 th and 10 th weeks of exposure, respectively are significantly higher than other treatments. The T4 mean values in the 6 th week of exposure are significantly higher than other treatments. The highest MDA mean value in this regard, was 40.05 ± 0.03 nM/mg obtained in T4 at the end of the 6 th week of exposure. The control mean values in the gill of the samples are significantly higher than other treatments in the 2 nd week of exposure. The T3 and T1 mean values in the 4 th and 6 th weeks of exposure, respectively are significantly higher than other treatments. The highest mean value of MDA in the gill was 34.98 ± 0.02 nM/mg obtained in T1 at the end of the 6 th week of exposure. In the samples exposed to CdVA, MDA production levels in the liver were generally low. The T3 mean values in the 6 th and 8 th weeks of exposure, respectively are significantly higher than other treatments. The highest mean value of MDA in the liver was 39.52 ± 0.05 nM/mg obtained in T3 at the end of the 6 th week of exposure. The T2 and T3 mean values in the 2 nd and 4 th weeks of exposure, respectively are significantly higher than
Effects of lead nitrate on glutathione production levels in Clarias gariepinus (Burchell, 1822) post juveniles
Journal of Aquatic Sciences, 2018
The effects of lead nitrate on glutathione (GSH) production levels in Clarias gariepinus post juv... more The effects of lead nitrate on glutathione (GSH) production levels in Clarias gariepinus post juveniles were investigated. The 96 hours LC 50 of the toxicant was determined. Six samples of the fish were exposed to sub-lethal concentrations of 0 mg/L, 28 mg/L, 43 mg/L and 57 mg/L with replicate in each case for a period of 28 days. Two samples of the fish were randomly selected from the treatments and control for the bioassay of GSH production levels in the kidney, liver and gill of the fish on the 14th and 28th day respectively. The results showed that 96 hours LC 50 for C. gariepinus exposed to lethal concentrations of lead nitrate was 284.189 mg/L. The GSH production levels were significantly lower (P≤0.05) in the kidney of the fish exposed to treatments 28 mg/L and 43 mg/L and in the liver of the fish exposed in all the treatments on both days 14 and 28, respectively. The GSH production levels were also significantly lower in the gill of the fish exposed in all the treatments. The liver of C. gariepinus exhibited a better control of the toxicant and therefore, a better biomarker of oxidative stress due to lead nitrate. Key Words : Glutathione, lead nitrate, 96 hours LC 50 , oxidative stress, Clarias gariepinus
Environmental pollution is on the increase all over the world principally due to anthropogenic ac... more Environmental pollution is on the increase all over the world principally due to anthropogenic activities. Of major concern among these environmental pollutants are heavy metals. Heavy metals could be essential or non-essential. Heavy metals such as Fe, Cu, Zn, Ni, Co, Cr, and Mn are vital to human only at lower concentrations, but they become more toxic when they are taken up more than the biorecommended limits (Shilpi et al., 2015). It is also known that even essential metals may be toxic on the biological activities of organisms above certain concentrations (Merciai et al., 2014). Among all the heavy metals (that are regarded as non-essential), Cd, Arsenic, Mercury and lead pose highest degree of toxicity and that is of great concern to plants and human health (Athar et al., 2018). Contamination of the ecosystem by heavy metals has given rise to one of the most important ecological and organismic problems, particularly human, early developmental stages of fish and animal life. Di...
Effects of cadmium chloride on the production of antioxidants such as reduced glutathione (GSH) i... more Effects of cadmium chloride on the production of antioxidants such as reduced glutathione (GSH) in Clarias gariepinus and how such effects can be ameliorated through administration of vitamins were investigated. C. gariepinus fingerlings were exposed to sub-lethal concentrations of Cd (00, 12mg/L, 16mg/L, 20mg/L and 24mg/L) with replicate in each case. 12mg/L each of the vitamins were administered across all bud. Fresh concentrations of both toxicant and vitamins were administered every 72 hours for a period of 12 weeks every time the water medium was changed. 3 samples of the fish were randomly selected and sacrificed from each aquarium tank every 2 weeks. The gills, kidneys and liver were excised from these specimens, homogenized in sodium phosphate buffer and then assayed for GSH production levels in each case. From the results: In Cd only group, the highest GSH level produced in the liver was 38.85±0.07µg/ml. In the liver of samples of CdVA group, the value (93.97±0.07µg/ml) inc...
Resources and Environment, 2015
Fresh water bodies all over the world are constantly faced with pollution challenges most of whic... more Fresh water bodies all over the world are constantly faced with pollution challenges most of which are anthropogenic in nature. Determination of physico-chemical parameters is one of the many routine practices of determining the health of the ecosystem and the survivability of the living biota within it. This research focuses on the temporal and spatial physico-chemical parameters of River Galma. Water samples were collected from five different locations along the river course from August, 2014 to January, 2015 for the determination of eleven physico-chemical parameters on monthly basis following standard methods. The results indicate high significance difference (P˂0.05) in biological oxygen demand, hardness, alkalinity, sulphate, nitrate, phosphate-phosphorus, total dissolved solids, electrical conductivity, and temperature of the sampling months with significance difference in dissolved oxygen. There were no significant differences amongst the sites. Electrical conductivity range...
International Journal of Fisheries and Aquatic Studies, 2021
The spatial and temporal variations in the Physico-chemical parameters and the abundance of macro... more The spatial and temporal variations in the Physico-chemical parameters and the abundance of macroinvertebrates in Gurara Reservoir, Kaduna State were evaluated monthly for 6months from February-July, 2018 using standard water sampling and modified kick sampling techniques, respectively. From the results, the water temperature ranged from 25.6-29.1ºC, Air temperature ranged from 23.7-32.9 ºC, pH ranged from 8.8-9.8, Electrical Conductivity ranged from 37-114µS/cm, Total Alkalinity ranged from 24-44mg/L, BOD ranged from 1.0-2.2mg/L, DO ranged from 2.0-4.8mg/L in all the stations. A total of 1801 individual species of macro-invertebrates in 12 families from 3 orders were collected from 3 stations during the research. The most dominant species are Melanoides tuberculata, followed by Corbicula nitens and Union mancus. The abundance of macro invertebrate was high during the dry season than raining season. The marginal high nutrient levels (Phosphate and nitrate) obtained at these stations during wet season are indication that the water body is stressed with organic input and increased high levels of anthropogenic activities. This study revealed that macro invertebrates communities responded to changes in habitat quality of the reservoir.
Egyptian Journal of Aquatic Biology and Fisheries, 2020
Applied Scientific Reports, 2017
The river ecosystem serves as ultimate sink for myriads of xenobiotic all over the world with del... more The river ecosystem serves as ultimate sink for myriads of xenobiotic all over the world with deleterious effects on the living biota within it. Histopathological alterations in kidney and liver of the catfish Clarias gariepinus (Burchell, 1822) were studied in River Galma, Zaria Nigeria. Twenty-five samples of Clarias gariepinus were exposed to the river ecosystem at the peak of rainfall in August, 2015 for 14 days at five stations along River Galma, using the cage system. Fish samples and controls from each station were subsequently harvested and transported to the laboratory for histopathological examination of liver and kidney. Results from photomicrographs of tissues from different stations revealed varying histopathological alterations which ranged from vacuolation, constrictions, necrosis and aggregations of cells to congestion of the blood vessels. These results indicated that River Galma is witnessing pollution. This calls for ameliorative measures by relevant authorities so as to protect aquatic life as well as the public from the toxic effects of aquatic environmental pollution.
This research focuses on the effects of some heavy metals on production of Vitamin E and C in Cla... more This research focuses on the effects of some heavy metals on production of Vitamin E and C in Clarias gariepinus in an in situ bioassay in River Galma.120 samples (40 per exposure) of 20-45g size range of juveniles were exposed to the river environment for fourteen days in a cage system at five different locations along the river course for three different periods of the year. Vitamins E and C were assayed for after the 14 th day of exposure. Heavy metal (Pb, Cr, Cd, Zn and Mn) contents were also tested for in digested pooled samples of water, livers and gills of the fish. The results indicate significant difference in the levels of Vitamin E and C production in the gill in all the months of exposure at P<0.05 level of significance but not in the liver. There were significant differences in the Chromium concentration in the gills and livers of the fish in all the exposures. Also, there was significant difference amongst the fish organs, water samples and Lead (Pb) concentrations. There were correlations amongst Vitamin E and C and the heavy metals. There was strong correlation between Vitamin E levels and Lead concentrations in all the exposure periods. This research also established the presence of heavy metals examined in varying degrees of concentrations in water samples and fish organs. Vitamin E and C can be used as biomarkers of pollution in River Galma to give early warning on environmental pollution to the community and policy makers.
The presence of pollutants in the environment of an aquatic organism such as fish can lead to the... more The presence of pollutants in the environment of an aquatic organism such as fish can lead to the production of reactive oxygen species and consequently, oxidative stress. The effects of lead nitrate on aspartate amino transferase (AST) in C. gariepinus and how such effects can be ameliorated through administration of vitamins were investigated. C. gariepinus fingerlings (whose initial weight ranged from 3-11g) were exposed to sub-lethal concentrations of Pb (00, 26mg/L, 44mg/L, 61mg/L and 79mg/L) with replicate in each case. 26mg/L of the vitamins in each case was administered across all bud. Fresh concentrations of both toxicant and vitamins were administered every 72 hours for a period of 12 weeks every time the water medium was changed. 3 samples of the fish were randomly selected and sacrificed from each aquarium tank every 2 weeks of the exposure period. The gills, kidneys and liver were excised from these specimens and homogenized in sodium phosphate buffer and then assayed f...
International Journal of Fisheries and Aquaculture, 2018
The effects of Lead Nitrate on catalase (CAT) production levels in post juvenile Clarias gariepin... more The effects of Lead Nitrate on catalase (CAT) production levels in post juvenile Clarias gariepinus were investigated. A total of 250 samples of the fish were acclimatized for two week. Six samples of the fish were exposed to the sub-lethal concentrations of 00, 28, 43 and 57 mg/L with replicate in each case for 28 days. Two samples of the fish were randomly selected from the treatments and control for the bioassay of catalase on the 14th and 28th day respectively. The fish organs (kidney, liver and gill) were excised from the fish and homogenized in sodium phosphate buffer (0.2 M, pH 8.0). The data generated were subjected to one-way analysis of variance followed by Duncan Multiple Range test where significant. The results showed that 96 h LC50 of C. gariepinus exposed to lethal concentrations of Lead Nitrate was 284.189 mg/L. The CAT production levels were significantly higher in the kidney of the fish exposed in 28 mg/L on day 14; 43 and 57 mg/L on day 28, respectively. The CAT p...
International Journal of Modern Botany, 2013
Biodiesel development in Nigeria over the years has been given little attention because of the my... more Biodiesel development in Nigeria over the years has been given little attention because of the myriads of economic strain and stress facing the country like any other third world country. Biodiesel is a renewable source of energy that has not been fully tapped. Biodiesel can facilitate clean air, readily usable in existing engines and transport facilities, capable of generating employ ment and inco me fo r citizens and country at large. The major b io mass world-wide is Jatropha plant which is currently generating interest in every economy of the world. The major means of converting the biomass into viable fuel is transesterification. The major problems facing the full exp loit of this modern fuel is surmountable including the fear of taking-up arable agricultural land. Various generations of biofuel feed-stocks can be made use of in place of agricultural crops. The benefits and prospects of biodiesel production is huge and numerous. Deliberate efforts should be made by the government in terms of massive capital investment, train ing of man-power in the field of biofuel or biodiesel development, granting tax holidays to would-be investors_ companies and individuals, amongst many other things. If adequate policy frame-work is put in place and necessary political will is exp ressed and applied to the develop ment and production of biodiesel in the country the economy would be better for it.
Some aspects of the biology of Hemisynodontis membranaceus (Geoffrey St-Hilaire, 1809) in Zaria w... more Some aspects of the biology of Hemisynodontis membranaceus (Geoffrey St-Hilaire, 1809) in Zaria were examined between the months of May and July, 2006. A total of 134 specimens were observed with the sex ratio of 1:1.23 males to females in all the months together. The mean standard length was 14.05cm while the body weight ranged from 22.8g to 318.5g with a mean of 75.3g. The length-weight relationship indicated positive and high correlation in both males (with 0.8809) and females (with 0.8479) and all the sexes combined (with 0.8269). The fish exhibited isometric growth in both sexes. The condition factor for both males and females indicated that the well-being was high through-out the period of study. The mean condition factor ranged from 2.50 to 2.84. The analysis of the stomach contents indicated that H. membranaceus is an omnivore with algae (which constituted 40.29%), plant material (29.10%) and insects (22.38%) as its main diets. Since H. membranaceus is an omnivore it can be used in large aquarium set-up to feed on mollusc, algae, insects and other aquatic organisms.
There is growing global concern about the future of non-renewable biomass in form of fossil fuel ... more There is growing global concern about the future of non-renewable biomass in form of fossil fuel and its attendant consequences on the environment as evident in global warming. There is also, ever growing demand for energy and the need for environmental susteinability. Renewable energy sources from agricultural wastes especially those from biennial and perennial crop can be employed in the generation of biogas that will not only be environmentally friendly but also capable of solving the challenges of competition of biofuel with food crops. This review focuses on the possibility of using biomass from banana and peach palm's wastes for biogas production with twin advantages of clean energy and environment. Biomethantion is one of the major processes of conversion of wastes to biogas in digesters via anaerobic digestion in the presence of microorganisms in optimal environmental conditions in terms of temperature and pH. It is well known that fossil fuel is finite no matter the deposits or reserves the world can boast of today. Biomass on the other hand, is abundant, renewable and available worldwide. If this energy source is tapped into effectively with concerted efforts from all and sundry, the economies of the developing world in particular and the whole world in general will be better for it.
The effects of lead nitrate on glutathione (GSH) production levels in Clarias gariepinus post juv... more The effects of lead nitrate on glutathione (GSH) production levels in Clarias gariepinus post juveniles were investigated. The 96 hours LC 50 of the toxicant was determined. Six samples of the fish were exposed to sub-lethal concentrations of 0 mg/L, 28 mg/L, 43 mg/L and 57 mg/L with replicate in each case for a period of 28 days. Two samples of the fish were randomly selected from the treatments and control for the bioassay of GSH production levels in the kidney, liver and gill of the fish on the 14 th and 28 th day respectively. The results showed that 96 hours LC 50 for C. gariepinus exposed to lethal concentrations of lead nitrate was 284.189 mg/L. The GSH production levels were significantly lower (P≤0.05) in the kidney of the fish exposed to treatments 28 mg/L and 43 mg/L and in the liver of the fish exposed in all the treatments on both days 14 and 28, respectively. The GSH production levels were also significantly lower in the gill of the fish exposed in all the treatments. The liver of C. gariepinus exhibited a better control of the toxicant and therefore, a better biomarker of oxidative stress due to lead nitrate.
Okoye C. Loveline, 2018
The effects of Lead Nitrate on catalase (CAT) production levels in post juvenile Clarias gariepin... more The effects of Lead Nitrate on catalase (CAT) production levels in post juvenile Clarias gariepinus were investigated. A total of 250 samples of the fish were acclimatized for two week. Six samples of the fish were exposed to the sub-lethal concentrations of 00, 28, 43 and 57 mg/L with replicate in each case for 28 days. Two samples of the fish were randomly selected from the treatments and control for the bioassay of catalase on the 14 th and 28 th day respectively. The fish organs (kidney, liver and gill) were excised from the fish and homogenized in sodium phosphate buffer (0.2 M, pH 8.0). The data generated were subjected to one-way analysis of variance followed by Duncan Multiple Range test where significant. The results showed that 96 h LC 50 of C. gariepinus exposed to lethal concentrations of Lead Nitrate was 284.189 mg/L. The CAT production levels were significantly higher in the kidney of the fish exposed in 28 mg/L on day 14; 43 and 57 mg/L on day 28, respectively. The CAT production levels were significantly higher in the gill of the fish exposed in 57 mg/L on day 14; 43 and 57 mg/L on day 28 respectively. The CAT production levels were significantly higher in the liver of the fish exposed in 28 and 57 mg/L on day 14 respectively. The highest production mean values of 149.55±43.65 and 152.80±40.40 U/mgprotein were obtained in the kidney of the fish exposed in 57 and 43 mg/L, respectively. Therefore, the kidney of the fish exhibited a better control of the toxicant and as such, catalase production level in this organ should be used in assessing the level of physiological changes in the fish.
Patrick Ozovehe Samuel, 2018
Acute toxicity assessment of lead nitrate ((PbNO3)2) on post juvenile Clarias gariepinus under la... more Acute toxicity assessment of lead nitrate ((PbNO3)2) on post juvenile Clarias gariepinus under laboratory conditions were investigated. A total of 150 samples of the fish were acclimatized for two week. 6 aquaria tanks were setup for determination of the 96hours LC50 with 6 samples of fish per tank. The lethal concentration values of lead nitrate used were 240mg/L, 260mg/L, 290mg/L, 320mg/L and 34mg/L with replicate in each case. The control setup was without the toxicant. The fish samples exhibited varying behavioural and physical changes which ranged from erratic swimming, poor feeding habit, frequent gasping for air at the surface of the tank, lacerations of the skin and secretion of mucus, and eventually death. The vigour and severity of these features were time and concentration dependent. The results showed that 96hours LC50 of Clarias gariepinus was 284.189mg/L. This indicated that greater quantity of the toxicant is needed to cause mortality in the fish and less deleterious at lower concentrations.
Patrick Ozovehe Samuel
The river ecosystem serves as ultimate sink for myriads of xenobiotic all over the world with del... more The river ecosystem serves as ultimate sink for myriads of xenobiotic all over the world with deleterious effects on the living biota within it. Histopathological alterations in kidney and liver of the catfish Clarias gariepinus (Burchell, 1822) were studied in River Galma, Zaria Nigeria. Twenty-five samples of Clarias gariepinus were exposed to the river ecosystem at the peak of rainfall in August, 2015 for 14 days at five stations along River Galma, using the cage system. Fish samples and controls from each station were subsequently harvested and transported to the laboratory for histopathological examination of liver and kidney. Results from photomicrographs of tissues from different stations revealed varying histopathological alterations which ranged from vacuolation, constrictions, necrosis and aggregations of cells to congestion of the blood vessels. These results indicated that River Galma is witnessing pollution. This calls for ameliorative measures by relevant authorities so as to protect aquatic life as well as the public from the toxic effects of aquatic environmental pollution.
Ayanwale AV, 2020
Effects of different temperature levels on the opercular respiratory rate of Clarias ang... more Effects of different temperature levels on the opercular respiratory rate of Clarias anguillaris fingerlings were investigated for a period of 6 weeks under laboratory conditions. Fifty fingerlings were raised in water temperatures of control (26.66±0.28), 30.00, 32.00, 34.000C with 2 replicates each respectively. Opercular Respiratory Rates (ORR), body weight, and physicochemical parameters were determined weekly based on standard methods. ORR was significantly (p< 0.05) reduced from 113.60 ± 7.67 to 105.50 ±10.23 opercular beats per minute from week 1 to 2 in the control temperature. ORR was also significantly (p<0.05) higher from 30 to 340C from week 1 to 2. A strong negative correlation was observed between body weight and ORR from all the treatments. Electrical conductivity (519.92±5.06 to 586.33±17.50 μS/cm) and Ammonia concentration (1.11±0.10 to 1.98±0.06 mg/L) were (p<0.05) higher from the control temperature to 30.000C. ORR of C. anguillaris fingerlings increased with an increase in temperature, while ORR decreased with an increase in fish size and duration of the experiment.The temperature had no effects on dissolved oxygen, biochemical oxygen demand and pH except bodyweight in weeks 1, 3 and 5. Ammonia concentration and electrical conductivity increased with an increase in temperature. The findings from
this study revealed that higher temperature levels affect the opercular respiratory rates, ammonia concentration, and electrical conductivity of Clarias anguillaris fingerlings in captivity.
Samuel PO
The anthropogenic activities culminating in environmental pollution all over the world that usual... more The anthropogenic activities culminating in environmental pollution all over the world that usually leads to release of plethora of pollutants such as cadmium calls for concern. In the present study the effects of cadmium chloride on the production of antioxidants such as Malondialdehyde (MDA) in C. gariepinus and how such effects can be ameliorated through administration of vitamins were investigated. C. gariepinus fingerlings (whose initial weight ranged from 3-11 g) were exposed to sub-lethal concentrations of Cd (00, 12 mg/L, 16 mg/L, 20 mg/L and 24 mg/L) with replicate in each case. Minimum concentration of the toxicant was taken as the concentration for each of the vitamins and administered across all bud. Fresh concentrations of both toxicant and vitamins were administered every 72 hours for a period of 12 weeks every time the water medium was changed. The various treatments group include Cd (Cd only with T1-T4 and replicates), CdVA (Cd+vitamin A with T1-T4 and replicates), CdVC (Cd+vitamin C with T1-T4 and replicates) and CdVE (Cd+vitamin E with T1-T4 and replicates). 3 samples of the fish were randomly selected and sacrificed from each aquarium tank every 2 weeks of the exposure period. The gills, kidneys and liver were excised from these specimens and homogenized in sodium phosphate buffer. From the results: samples exposed to Cd only group, the MDA production levels in the liver were generally low. The T2 and T3 mean values in the 6 th and 10 th weeks of exposure, respectively are significantly higher than other treatments including the control. The control mean values in the 8 th week of exposure are significantly higher than other treatments. The highest mean value of MDA in the liver was 40.17 ± 0.05 nM/mg obtained in T3 at the end of the 2 nd week of exposure. In the kidney, the control mean values in the 2 nd , 4 th , 8 th and 10 th weeks of exposure, respectively are significantly higher than other treatments. The T4 mean values in the 6 th week of exposure are significantly higher than other treatments. The highest MDA mean value in this regard, was 40.05 ± 0.03 nM/mg obtained in T4 at the end of the 6 th week of exposure. The control mean values in the gill of the samples are significantly higher than other treatments in the 2 nd week of exposure. The T3 and T1 mean values in the 4 th and 6 th weeks of exposure, respectively are significantly higher than other treatments. The highest mean value of MDA in the gill was 34.98 ± 0.02 nM/mg obtained in T1 at the end of the 6 th week of exposure. In the samples exposed to CdVA, MDA production levels in the liver were generally low. The T3 mean values in the 6 th and 8 th weeks of exposure, respectively are significantly higher than other treatments. The highest mean value of MDA in the liver was 39.52 ± 0.05 nM/mg obtained in T3 at the end of the 6 th week of exposure. The T2 and T3 mean values in the 2 nd and 4 th weeks of exposure, respectively are significantly higher than
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Papers by Dr. Ozovehe Patrick Samuel
this study revealed that higher temperature levels affect the opercular respiratory rates, ammonia concentration, and electrical conductivity of Clarias anguillaris fingerlings in captivity.