Books by Prof. Simeon Oluwatoyin Ayoola
Papers by Prof. Simeon Oluwatoyin Ayoola
African Journal of Agricultural Research, Dec 31, 2008
Fish are particularly sensitive to a wide variety of agrochemicals including glyphosate herbicide... more Fish are particularly sensitive to a wide variety of agrochemicals including glyphosate herbicide that may arise from not only deliberate discharge of these chemicals into waterways but also from approved agricultural practices. In the present study, the toxicity of glyphosate an herbicide was investigated with emphasis on histopathological effects. Nile tilapias (Oreochromis niloticus) juvenile 15 ± 1.0 g were exposed to 0, 2, 9, 30, 97, 310 mg/l of glyphosate. The lethal concentration (LC 50) value of glyphosate was 1.05 mg/l for 96 h of exposure. Glyphosate concentration corresponding to the 96 h LC 50 values for juvenile tilapia was used to study the effects of glyphosate exposure for 4 days in inducing histopathological changes of gills, livers, kidneys and brains. In the gills, filament cell proliferation, lamellar fusion, lamellar cell hyperplasia, and epithelial lifting were observed. In the liver, there was vacuolation of hepatocytes and necrosis. Kidney lesion consisted of hyaline droplets in the tubular epithelial cells and pkynosis. The brain lesion also consisted of generalized neuronal degeneration and spongiosis. The changes in these tissues occur predominantly in the 96 h exposure. Respiratory stress, erratic swimming and instant death of fish were observed in exposed fish, which varied with the concentration of the toxicant and this showed that mortality increased with increase in concentration. Glyphosate is highly toxic to Nile tilapias, which are more susceptible to this herbicide; therefore their use near fish farm or in area close to aquatic environment should be discouraged.
This study examined the willingness of secondary school students to choice of aquaculture as a pr... more This study examined the willingness of secondary school students to choice of aquaculture as a profession in Okitipupa Local Government Area of Ondo State, Nigeria. The sample was made up of 100 science students randomly selected among science students in two public secondary schools. Questionnaire was used in data collection. Data were analysed by the use of frequency counts, percentages and Chi-square. The findings revealed among others that 52% of respondents were aware of Aquaculture as a profession, 56% were willing to study aquaculture with the award of scholarship; gender and parental educational level are not significant to the willingness of secondary school students to study aquaculture (p>0.05). It follows that interest of students in the profession should be aroused starting from the secondary school levels. Based on this study, it is recommended that Governments, public and private organizations, individuals and NGOs should embark on various enlightenment programmes ...
Iranica Journal of Energy and Environment, 2017
Industrial waste discharge has increased the hazard of water pollution. The total hydrocarbon con... more Industrial waste discharge has increased the hazard of water pollution. The total hydrocarbon content and bioaccumulation of heavy metals in Sarotherodon melanotheron at Atlas cove area and at Okobaba end of Lagoon Lagos were assessed between November, 2014 and January, 2015. The physicochemical parameters were determined according to APHA-AWWA-WEF and heavy metals in the fish species were determined using Atomic Absorption Spectrometer. The total hydrocarbon content (THC) in the fish samples were analysed by using Soxhlet extraction gravimetric methods. The heavy metal values evaluated are Fe, Cr, Pb, Ni and Cu. The concentration of Iron (Fe) in Sarotherodon melanotheron was 72.72 ± 125.95mg/kg, Chromium (Cr)-10.29 ± 4.61mg/kg; Lead (Pb)-1.08 ± 0.23mg/kg; Nickel (Ni)-0.39 ± 0.26mg/kg; and Copper (Cu)-0.20 ± 0.26mg/kg at Atlas cove area while at Okobaba the concentration were;Fe-115.98±87,Cr-5.25±1.02,Pb-2.04±1.50,Ni-0.78±0.08,and Cu is 0.36±0.15mg/kg. The levels of accumulation of all the heavy metals in Sarotherodon melanotheron were above the WHO permissible limits. The concentration of n-alkanes in Sarotherodon melanotheron at Atlas cove was 164.69 ± 97.04µg/g, polycyclic aromatic hydrocarbon (PAH) was 73.58 ± 72.48µg/g, and total petroleum hydrocarbon was 526.67 ± 214.34µg/g. The average intake of polycyclic aromatic hydrocarbon through fish consumption at Atlas cove area was estimated to be 5039.94 ± 49.2mg/kg; body weight/day. The mean concentration of nalkanes hydrocarbon in Sarotherodon melanotheron at Okobaba was 152.62±54.11µg/g, the Polycyclic Aromatic Hydrocarbon (PAH) was 74.4±50.30 µg/g.The carcinogenic high molecular weight polycyclic aromatic hydrocarbons (HMW-PAH) were of higher concentrations than the lower molecular weight polycyclic aromatic hydrocarbon (LMW-PAH). Therefore, Atlas cove area is more exposed to carcinogenic health risks associated with the consumption of the studied fish than Okobaba end of Lagos Lagoon. This indicates significant carcinogenic health risks associated with the consumption of black jaw Tilapia fish caught from the study areas.
American-Eurasian Journal of Toxicological Sciences, 2014
The aquatic environment makes up the major part of our environment and resources, its safety is d... more The aquatic environment makes up the major part of our environment and resources, its safety is directly related to the safety of our health and food security. This study investigated the cytogenetic effect of black jaw Tilapia, Sarotherodon melanotheron exposed to pawpaw leaf ( Carica papaya L.) as replacement for rice bran for twelve weeks (90 days). The haematological effects of feeding Carica papaya leaf meal rations to Sarotherodon melanotheron Juvenile were also carried out. The study also investigated the haematological effects of feeding Carica papaya leaf meal rations to Sarotherodon melanotheron Juvenile. The treatments of the pawpaw leaves for the experiment were T 0 (0%), T 1 (25%), T 2 (50%), T 3 (75%) and T 4 (100%). The physico-chemical parameters showed a significant difference (p 0.05) in the micronuclei present in 30 day in all the treatment while, day 60 and 90 showed a significant difference (p < 0.05) in all treatments. Analysis of Variance ( ANOVA) showed a ...
African Journal of Livestock Extension, 2010
Effects of oven and air-dried pituitary hormone on the ovulative capacity of gravid Clarias garie... more Effects of oven and air-dried pituitary hormone on the ovulative capacity of gravid Clarias gariepinus was carried out in a commercial fish hatchery farm between the months of October and November, 2008. Nine female gravid Clarias gariepinus weighing about 1kg each was injected with oven dried, air dried and wet pituitary hormone (wet pituitary hormone acted as the control). Injected brooders underwent indoor temperature conditions varied from 240C -270C, ovulated eggs were manually expressed and incubated. Differences occurred among the means of the treatment with respect to weight of the egg per treatment and rate of hatchability among the samples. There is no significant difference between oven dried pituitary (Treatment 2) and (Treatment 1) which is the control except in the number of eggs. The mean difference percentage hatching and weight of ovulated egg is significant at (p < 0.05).
African Journal of Livestock Extension, 2013
Global wild fisheries are in decline, it is therefore important to domesticate fish production to... more Global wild fisheries are in decline, it is therefore important to domesticate fish production to meet the protein need of the society with the view to use natural herb to achieve sustainable production. The effect of different concentrations of garlic (Allium sativum) supplement in fish diet on growth and haematological parameters of Clarias gariepinus Juvenile was investigated. Fifteen tanks were used and 10 Clarias gariepinus Juvenile with mean weight (51.41 ± 0.23) were separated into five experimental group. Diet T5 contain 0g Allium sativum (control diet) while other group contain 1.0g, 1.5g, 2.0g and 2.5g concentrations of garlic in diet and fed at 3% body weight per day . Result shows that Allium sativum supplemented diets have significant effect on weight gain of C. gariepinus when compared to fish in the control diet. However, final fish weight was significantly (P<0.05) higher than the initial fish weight in all concentrations of garlic in fish diet and in the contro...
The occurrence, length-frequency distribution, length-weight relationship and condition factors o... more The occurrence, length-frequency distribution, length-weight relationship and condition factors of 449 specimens of cichlids, Sarotherodon melanotheron, Tilapia zilli, Tilapia guineensis and Hemichromis fasciatus from Lagos Lagoon were investigated from September 2009 - February 2010. The relative abundance of the species collected from the lagoon was: S. melanotheron (45.43%), T. zilli (26.73%), T. guineensis (26.06%) and H. fasciatus (1.78%). All the cichlids were found throughout the sampling peri od except H. fasciatus which was collected only in February. The standard length of S. melanotheron ranged from 8.0 – 14.5cm (weight: 22.00 – 90.00g), T. zilli (SL: 8.0 – 14.5cm; weight: 32.80 – 108.00g), T. guineensis (SL: 9.0 – 17.0cm; weight: 42.00 – 85.00g) and H. fasciatus (SL: 11.0 – 14.0cm; weight: 65.00 –84.00g). The frequency polygon reflected one age group in S. melanotheron, one age group in T. zilli, three age groups in T. guineensis and two age groups in H. fasciatus. The c...
As human population increases with the growth of industrialization, there is a resultant increase... more As human population increases with the growth of industrialization, there is a resultant increase in the rate of pollution in aquatic ecosystems. Changes in plasma concentrations can be indicative of stress in fishes exposed to pollutants. This study investigated the toxicity and plasma indices changes in Chrysichthys nigrodigitatus of Bariga landing site, Lagos lagoon. Physiochemical parameter of Bariga landing site (Lagos lagoon) were also analyzed. Temperature, pH, dissolved oxygen, salinity, transparency had a mean of 25±1.0, 7.44±0.05, 4.33±0.15, 15.33±3.06, 73.17±0.76 respectively. TSS, phosphate, COD, BOD, nitrate, TDS had a mean value of 2.0±0.58, 2.0±0.58, 13.1±1.015, 8.87±0.23, 5.3±0.1, 161.13±9.50 respectively. The mean value of AST, ALT, ALP, CHOL, GLU, TP enzymes activity in the plasma of Chrysichthys nigrodigitatus from the month of May to July are 48.26±77.54, 21.79±13.49, 62.10±44.198, 86.21±27.64, 51.18±10.78, 24.58±14.10 respectively. The AST, ALT, ALP found within...
The differential acute toxicity of aqueous and ethanolic extracts of Ipomoea aquatica leaf on Nil... more The differential acute toxicity of aqueous and ethanolic extracts of Ipomoea aquatica leaf on Nile Tilapia, Oreochromis niloticus were carried out under laboratory conditions. The LC50 after 96hr of exposure for aqueous and ethanolic extracts of Ipomoea aquatica were 2.659g/L and 0.196g/L respectively. These values showed that ethanolic extract of Ipomoea aquatica was more toxic than its aqueous extract. Signs of agitated behaviours, respiratory distress and abnormal nervous behaviors including eventual deaths were observed in exposed fish. Control fish neither died nor exhibited any unusual behaviour. The randomized analysis of variance (ANOVA) showed that there were significant differences (P<0.05) in the quantal response (mortality) of O. niloticus to aqueous and ethanolic extracts of I. aquatica at 24hrs, 48hrs, 72hrs and 96hrs of exposure period. It was investigated that leaf of Ipomoea aquatica has piscicidal property and can be put into use in the control and management of...
This study was carried out to evaluate the use of Ocimum gratissimum leaves on the growth perform... more This study was carried out to evaluate the use of Ocimum gratissimum leaves on the growth performance 3 and haematological parameters of Oreochromis niloticus juveniles. Five tanks (21.5x14.5x9cm ) containing 10 Oreochromis niloticus juveniles were fed with five isonitrogenous diets (27.11% crude protein) containing varying inclusion of O. gratissimum (Control diet 0%, O. gratissimum T1=25%, T2=50%, T3= 75%, and T4= 100%). The fish were fed twice daily for an experimental period of 12 weeks. The fish in tank T3 (0.23inclusion of O. gratissimum) had the best weight gain 26.00±3.00g which ranges from 22.00±1.00 to 26.00±3.00g. The highest specific growth rate of 0.56±0.06 was recorded in tank T3with a range of 0.52±0.01 to 0.56±0.06. The highest food conversion ratio 1.25±0.09 was recorded in tank T1 (25%0.075 inclusion of O. gratissimum) with a range of 1.11±0.23to 1.25±0.09. The highest protein efficiency ratio 0.03±0.01was also recorded in T3 (0.23 inclusion of O. gratissimum) with...
A study was conducted to determine distribution and abundance of fish over two years (dry and wet... more A study was conducted to determine distribution and abundance of fish over two years (dry and wet seasons) in lagoon systems of Ogun waterside Local Government Area, Ogun State, Nigeria. Fish sampling was carried out in four selected stations based on catch. Physical and chemical characteristics of the lagoon systems and fish distribution was also carried out. The study revealed that Bagridae represented by Chrysichthys nigrodigitatus contributed the highest number of fish in the two seasons. Fish species were evenly distributed in the wet seasons than dry seasons. Simpson index (D) computed for the 4 sites are 0.29, 0.14, 0.14 and 0.29 respectively for Ode-Omi, Awodikora, Eba and Ebute-Okun in the dry seasons and 0.09, 0.10, 0.07 and 0.09 for dry seasons. There are positive correlations between fish number and some physico-chemical parameters, phosphate (r= 0.74), Ammonia (r= 0.4*). There are variations among physico-chemical parameters of water samples. Information revealed by this study will be useful in fisheries resource management for the study locations.
Potentially harmful substances such as pesticides, heavy metals, and hydro chemicals are often re... more Potentially harmful substances such as pesticides, heavy metals, and hydro chemicals are often released into the aquatic environment. The objective of the present study was to assess the concentration of lead, copper, cadmium, chromium, and nickel in water samples from two different points (Mid-stream and downstream), also determine the levels of Lead, Zinc, Manganese and copper in four commercially important fish species, Pseudotolithus senegalensis (croaker fish) and Ethmalosa fimbriata (bonga), Oreochromis mossambicus (Tilapia fish) and Bagrus bayad (silver catfish) from Makoko water body, Yaba, Lagos, Nigeria. Histopathological profile of the fish species selected was also examined. The results were compared to the World Health Organization (WHO) acceptable limit. The concentrations of the heavy metals were analyzed using Perkin Atomic Absorption Spectrophotometer (AAS). Pseudotholithus senegalensis had 3.01±0.02, 2.41±0.02, 3.48±0.01, 1.04±0.10 mg kg as the mean concentration o...
A total of 2400 Sarotherodon melanotheron fry were reared in six (6) plastic (High density polyet... more A total of 2400 Sarotherodon melanotheron fry were reared in six (6) plastic (High density polyethylene) tanks for three months. Each tank was stocked with 400 fry of which three tanks T1 T1 and T1 1, 2 3, served as treatment tanks while the other three tanks T0 , T0 and T0 , served as control. The treatment tanks 1 2 3 were administered with 17a-methyl testosterone hormone, which functioned as a sex reversal hormone for 30 days and further reared for 60 days in which physico-chemical parameters were taken and growth performance was evaluated. The results show that temperature in the broodstook ponds was 29.5°C±1.2°C, Dissolve Oxygen (DO) of 6.222mg/L ±1.502 mg/L and hydrogen ion concentration (pH) value of 9.8±0.476. This did not alter spawning ability in fresh water. Water parameters for control were 29.5±1.2°C, 8.4 mg/L and 6.8±0.3 for Temperature, DO and pH respectively while treatment tank has temperature of 27.8±0.7°C, DO of 8.46±0.05 mg/L and pH values of 6.53±0.28. Sex rever...
African Journal of Biotechnology, 2008
The use of biotechnology in various aspects of human endeavour have obviously created a great imp... more The use of biotechnology in various aspects of human endeavour have obviously created a great impact but not without some risks. Not withstanding, there is still the need for its adoption as more of the already adopted biotechnologies are being improved upon with lesser demerits. Aquaculture is not also left out in the application of biotechnological approaches. The aquaculture industry is currently faced with solving the simultaneous problems of developing economically viable production systems, reducing the impact on the environment and improving public perception. Whereas significant progress has been made in understanding production systems, improvement in cultured stocks has not kept pace with productivity demands. This paper considered aquaculture as the only way to increase fish production and also discusses technical environmental and management considerations regarding the use of genetically modified fish organism (e.g. fish) in aquaculture. This paper discusses advantage o...
Aceh Journal of Animal Science, 2020
Growth and all activities of fish depend significantly on the food they consume. However, with t... more Growth and all activities of fish depend significantly on the food they consume. However, with the rising price of conventional feedstuffs, there is a need to investigate less expensive and readily available plant source as an additive. This research is designed to study the effect of dietary Aloe vera on the growth performance of Oreochromis niloticus juveniles (41.71±0.78g) and its effect on genotoxicity (MN: Micronucleus; LB: Lobed; BD: Bud; BL: Blebbed; BN: Binucleated; NT: Notched). This research investigated the growth performance and genotoxicity activity of Oreochromis niloticus juveniles in a tank culture system. Aloe vera (fine powder) was used as a test ingredient in the feed formulation at five inclusion levels (T1 = 5g, T2 =10g, T3 =15g, T4 =20g, T5 =25g) and the Control diet (C0) without the test ingredient. Test diets were fed to Oreochromis niloticus juveniles, and each diet was assigned to the treatments and control overall in triplicates. Feeding with test die...
ACEH JOURNAL OF ANIMAL SCIENCE, 2017
The fish abundance was determined by monitoring and recording the fish-catch data at the Otto Jet... more The fish abundance was determined by monitoring and recording the fish-catch data at the Otto Jetty in the Ologe lagoon. The diversity indices used for the purpose of this project were Species richness (S) and Shannon-Weiner index (H´). Three fish species from the lagoon were used for the micronucleus assay and nuclear aberrations; these are Tilapia guineensis, Sarotherodon melanoteron, and Chrysichthys nigrodigitatus. Diversity indices (H) obtained for the months of June, July, August and September were 2.61, 2.54, 2.54, 2.61 respectively while evenness (J) for the months were 0.64, 0.60, 0.53, 0.44 respectively. Apart from the presence of micronucleus, the genotoxicity assay also showed the presence of binucleated nucleus and blebbed nucleus. These are evidences that Ologe lagoon has a certain level of pollution, though in a minimal level. As advanced by this research work, there is great variation in fish composition and abundance in Ologe lagoon in relation to changes in the physical and chemical state of the water in the lagoon during the months of this research and this is very crucial to the biological life of the lagoon. However, anthropogenic activities should be regulated so as to prevent the level of pollution from increasing beyond tolerable limits.
ACEH JOURNAL OF ANIMAL SCIENCE, 2017
A plant has become a preferred source of protein for fish species in aquaculture. A twelve-week f... more A plant has become a preferred source of protein for fish species in aquaculture. A twelve-week feeding trial was carried out in order to assess the effect of feeding walnut leaves on haematological and biochemical parameters as well as the genotoxicity level on Clarias gariepinus fingerlings as a bio-indicator of their health status and overall response of the fish towards the experimental diets. One hundred and fifty fingerlings of Clarias gariepinus of mean weight 6.90±0.2g were stocked randomly as ten fish per tank (52.5 X 33.5 X 21 cm 3) in triplicate. Fish were fed to satiation and the water changed every day to maintain good water quality. Five experimental diets with 40% crude protein each were formulated; the control, without the test ingredient and the other four diets (test diets1, 2, 3 and 4) contained 25%, 50%, 75% and 100% inclusion respectively. The Control diet had the highest mean weight gain (P < 0.05) (118.8±17.3) among the entire group. A similar pattern was observed in specific growth rate. The least significant (P < 0.05) feed conversion ratio was recorded by the Control diet(0.68±0.03), the diet also recorded the best protein efficiency ratio (3.53±0.23).The genotoxicity test shows that some Micronucleus of the test diets were normal, lobed and binucleated nucleus compared to the Control diet. The fish fed with T. conophorum showed a significant difference in haematological values when compared to the values of fish fed the control diet. The fish fed with T. conophorum showed a significant difference in biochemical value when compared with control diet. There was a reduction in the biochemical values of the fish fed T. Conophorum with Cholesterol (2.20±0.05) Albumin (8.35±0.21) and Triglyceride (0.98±0.13) compared with the values of fish fed with the control diet with cholesterol (3.81±0.07) Albumin (12.35±2.33) and Triglyceride (7.29±7.02). It was concluded that using T. Conophorum leaves as feed for Clarias gariepinus enhances the growth of the fish. Therefore, partial replacement of feed T. Conophorum should be encouraged.
Aceh Journal of Animal Science, 2019
Aquaculture industry is facing challenges of the high cost of fish feed, and therefore it is very... more Aquaculture industry is facing challenges of the high cost of fish feed, and therefore it is very crucial to explore the alternative raw materials for feed formulation at the lowest cost. Therefore, the objective of the present study was to evaluate the effect of Plukenetia conophora shells on the growth, haematological and biochemical parameters, and its genotoxicity on African catfish Clarias gariepinus juveniles. Five experimental diets were formulated having three replicates at 0% (0WS), 25% (25WS), 50% (50WS), 75% (75WS) and 100% (100WS) inclusion of walnut shell respectively. The fishes were fed on experimental diet two time a day for 12 weeks. The results showed that the fish in tank 25WS had the best weight gain with the mean of 33.5±5.8 g and the least was recorded in tank 100WS. The specific growth rate was highest in-tank 75WS with the mean value of 0.46±0.05 g was recorded. The highest feed intake was found in fish fed with 25% inclusion of P. conophora. The fish fed wi...
Aceh Journal of Animal Science, 2019
Potentially harmful substances such as pesticides, heavy metals, and hydro chemicals are often re... more Potentially harmful substances such as pesticides, heavy metals, and hydro chemicals are often released into the aquatic environment. The objective of the present study was to assess the concentration of lead, copper, cadmium, chromium, and nickel in water samples from two different points (Mid-stream and downstream), also determine the levelsof Lead, Zinc, Manganese and copper in four commercially important fish species, Pseudotolithus senegalensis (croaker fish) and Ethmalosa fimbriata (bonga), Oreochromis mossambicus (Tilapia fish) and Bagrus bayad (silver catfish) from Makoko water body, Yaba, Lagos, Nigeria. Histopathological profile of the fish species selected was also examined. The results were compared to the World Health Organization (WHO) acceptable limit.The concentrations of the heavy metals were analyzed using Perkin Atomic Absorption Spectrophotometer (AAS). Pseudotholithus senegalensishad 3.01±0.02, 2.41±0.02, 3.48±0.01, 1.04±0.10 mg kg-1as the mean concentration of ...
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Books by Prof. Simeon Oluwatoyin Ayoola
Papers by Prof. Simeon Oluwatoyin Ayoola