Department Of Zoology

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https://ir.unilag.edu.ng/handle/123456789/3397
The Department offers courses which will enable the Zoology student acquire a considerable knowledge of the animal kingdom such as classification, anatomy, physiology, evolution, phylogenetic relationship and adaptations to environment of the major animal group from protozoa to mammals. The foci of the programme are General Zoology, Applied Entomology, Parasitology, Ecotoxicology and Conservation.

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    Open Access
    The artificial substrate preference of invertebrates in Ogbe Creek, Lagos, Nigeria
    (Life Science Journal, 2006-05-09) Saliu, J.; Ovuorie, U.
    The colonisation patterns of the invertebrates of Ogbe Creek on four different types of artificial substrates (Kakaban, gravel bucket, glass and wood) was investigated within the period of September and November, 2002. A total number of 100,700/cm invertebrates comprising of 33 species were harvested. The gravel bucket supported the highest number of invertebrates, 46,740/cm comprising 17 species, while the glass substrate had the lowest number of invertebrate’s 2,100 /cm comprising 11 species (p < 0.05). The Kakaban substrate had the highest species richness (5.55) while the wood had the lowest (2.78). The four artificial substrates showed selectivity with respects to the organism that colonised them. The ability of the invertebrates to colonise artificial substrates was found to be influenced by the nature and permanence of the substrate.
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    Open Access
    Helminth Bioload of Chrysichthys nigrodigitatus (Lacepede 1802) from Lekki Lagoon Lagos, Nigeria
    (2007-04-11) Akinsanya, B; Otubanjo, O.A; Ibidapo, C.A
    Two hundred and sixty randomly selected specimens of a common fish, Chrysichthys nigrodigitatus (Lacepede 1802) collected over a period of one year from Lekki Lagoon, Lagos were subjected to parasitological examinations. The prevalence of helminth infections was 12.7%. Thirty three (33) of the fish specimens examined were infected with gastrointestinal helminth parasites. A total of seventy eight (78) parasite specimens were recovered from the fish specimens examined. The males (205) recorded a lower rate of infection (10.7%) than the females (55) which had a prevalence of 20%. Helminth parasites recovered include a cestode, Proteocephalus sp, an aspidogastrid trematode, Aspidogastrea africanus, and a nematode Paracamallanus cyathopharynx. Worm burden and intensity were low and independent of sex and age of fish. No seasonal variation in parasite intensity was observed.
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    Open Access
    Estimation of “environmentally sensitive” dispersal ratios for chemical dispersants used in crude oil spill control
    (The Environmentalist, 2009-12) Otitoloju, Adebayo A.; Popoola, Temitope O.
    The toxicities of two dispersants (Biosolve and OSD 9460), Forcados light crude oil and their mixtures based on ratios 6:1, 9:1, and 12:1 (v/v) were evaluated against the juvenile stage of African catfish, Clarias gariepinus, in laboratory bioassays. On the basis of the derived toxicity indices, Biosolve (96-h LC50 = 0.211 μl/l) was found to be about 27,284 times more toxic than crude oil (96-h LC50 = 5.757 ml/l) and 6,450 times more toxic than OSD 9460 (96-h LC50 = 1.361 ml/l). OSD 9460 was also found to be four times more toxic than crude oil when acting alone against C. gariepinus. Toxicity evaluations of the mixtures of crude oil/dispersants mixtures varied, depending largely upon the proportion of addition of the mixture components. The interactions between mixture of crude oil and Biosolve at the test ratios of 6:1, 9:1, and 12:1 were found to conform with the model of synergism (SR = 7,655, 14,876, and 8,792, respectively), and the mixtures were therefore more toxic than the crude oil acting singly. Similarly, the interactions between mixture of crude oil and OSD 9460 at the test ratios of 6:1 and 9:1 also conformed to the model of synergism (SR = 2.2 and 1.84, respectively). Interactions between the dispersant OSD 9460 and the crude oil at test ratio 12:1, however, conformed to the model of antagonism (SR = 0.84), indicating that the mixture was less toxic than crude oil acting alone. The results of the emulsification potential of OSD 9460 and Biosolve [measured in terms of optical transmittance (%)] prepared at the dispersal ratios 6:1, 9:1, and 12:1 revealed that the dispersal ratio of 6:1 achieved the highest emulsification of the crude oil with optical transmittance value of 4% and 6%, respectively. Estimation of an “environmentally sensitive” dispersal ratio for OSD 9460 and Biosolve revealed the optimum dispersal ratio for OSD 9460 range between ratios 7.5:1 and 9:1, while for Biosolve such an optimum dispersal ratio was indeterminate within the range of test dispersal ratios. The implications of these results in setting manufacturer’s and regulatory dispersal ratios for chemical dispersants used for oil spill control were discussed.
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    Open Access
    Migration patterns and morphometrics of Common Sandpipers Actitis hypoleucos at Ottenby, southeastern Sweden
    (Ringing & Migration, 2011) Iwajomo, Soladoye B.; Hedenström, Anders
    Current knowledge of the migration of the Common Sandpiper Actitis hypoleucos is still limited. The species has been ringed at Ottenby Bird Observatory, southeast Sweden, since 1947, allowing for analyses of long-term and seasonal trends. We analysed trapping data for 1,942 adults and 3,290 juveniles with respect to patterns in phenology, morphometrics, and fuel load. We used fuel loads to estimate potential flight ranges. The number of adult birds trapped increased significantly over the years, whereas juveniles declined. Median passage date was 27 July and 7 August for adult and juvenile birds respectively, and juveniles showed a significant advancement in median passage date. Mean fuel loads were 28.8% and 27.8% of lean body mass (LBM) for adult and juvenile birds respectively, while maximum fuel load was as high as 98.7% in juveniles and 105.4% in adults. Fuel load increased significantly with date in juveniles but declined in adults. Advancement in passage of juvenile birds over the year is possibly due to climate change. Also, the average adult and juvenile are theoretically capable of a direct flight to central France; a major recovery area. Fuel load patterns suggest that in autumn, the two age classes use different migration strategies.
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    Open Access
    The stopover behaviour of the Garden Warbler Sylvia borin in Obudu, southeast Nigeria
    (Ornis Svecica, 2011) Iwajomo, Soladoye Babatola; Ottosson, Ulf; Barshep, Yahkat; Helseth, Anders; Hulme, Mark F.; Stevens, Matthew; Waldenström, Jonas
    The Garden Warbler breeds in the Palaearctic and migrates to sub-Saharan Africa for the non-breeding season. We studied its passage, body mass and moult at the Obudu Plateau in southeast Nigeria in October–December 2005 and December 2007–January 2008. In Nigeria, Garden Warblers in the Guinea savanna have been shown to increase body mass in October–November, preparing for migration to wintering sites further south. They begin to arrive at Obudu from mid-October and the numbers gradually increase with time; median date of passage was 3 December. This influx is clearly different from that which has been recorded for other sites in West Africa. The patterns in wing length and size-corrected body mass of individuals suggest a difference in the migration time of individuals of different sizes in the two years. Average fuel loads were lower at Obudu than has been reported in Central Nigeria. This, and the capture of moulting individuals, suggests that Garden Warblers may not embark on a longer journey southwards in mid winter, and possibly may even winter at Obudu.
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    Open Access
    Autumn phenology and morphometrics in the Garden Warbler Sylvia borin at the Ottenby Bird Observatory, Sweden
    (Ornis Fennica, 2012) Iwajomo, Soladoye Babatola; Hedenstrom, Anders; Ottosson, Ulf
    Trapping and ringing near ecological barriers can provide useful information about the migration strategies of bird species. In this paper we analyzed ringing data of the Garden Warbler, collected within the period of 1950–2008 at the Ottenby Bird Observatory, south-eastern Sweden, and describe patterns in migration phenology, morphometrics and fuel load. A total of 4,351 individuals aged as either adults or juveniles were ringed during the period (yearly averages 7.3 adults and 83.1 juveniles) in addition to 1,514 birds of unknown age. Both age-specific and combined yearly totals did not significantly vary over the years.Median passage dates were 24 August, 30 August and 2 September for adults, juveniles and birds of unknown age, respectively.Median passage did not change significantly over the years. Among adults, larger individuals passed the observatory earlier than smaller individuals. The average fuel load was estimated at 24.3% of Lean Body Mass (LBM), and late-migrating individuals had higher fuel deposits than early migrants. Maximum fuel load was estimated at 82.5% of LBM; such an individual may be capable of a direct flight from Ottenby region to the Mediterranean area.
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    Open Access
    Influence of Volatile Organic Solvents’ Inhalation on Activity Quotient and Biochemical Indices of Mus musculus.
    (Journal of Environmental and Occupational Science, 2012) Akpan, Kenneth V.; Sogbanmu, Temitope O.; Otitoloju, Adebayo A.
    The influence of volatile organic solvents (nitrocellulose thinner, gasoline and xylene) on the activity quotient and liver biochemical indices of laboratory mice, Mus musculus over a period of 60 days were evaluated. The study entailed the use of a modified nose inhalation exposure method in which the exposure chambers were saturated with the test chemicals for 8 hours daily following which they were transferred to the vapour- free section of the chamber. The estimation of activity quotient by day 60 indicated that mice exposed to xylene were most restless followed by nitrocellulose thinner and gasoline (least restless) with activity quotient values of 0.69, 0.58 and 0.21 respectively. The results of the biochemical indices showed that there was a significant decrease (p<0.05) in the levels of antioxidant enzymes such as reduced gluthathione (GSH), superoxide dismutase (SOD) and catalase (CAT) in exposed mice from day 21 to 60 compared to control. Furthermore, the level of lipid peroxidation indicated by malondialdehyde (MDA) was found to be significantly higher (p<0.05) in exposed mice compared to control. The significance of these findings is that workers (laboratory technicians, painters and petrol station attendants) who are occupationally exposed to these volatile organic solvents for elongated periods may be at risk of lung related disorders.
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    Open Access
    Diversity of the Edible Fishes of the Lagos Lagoon, Nigeria and the Public Health Concerns Based on their Lead (Pb) Content.
    (Academic Journals, 2012-02-09) Ajagbe, F.E; Osibona, A.O; Otitoloju, A.A
    In this study, a total of eighteen fish species were recorded in the Lagos Lagoon, Nigeria during a one year survey. Among the animals species recorded, the following, Galeoides decadactylus, Dentex gibbosus, Elops lacerta, Scomber japonicus, Ethmalosa fimbriata, Lutjanus agennes, Caranx senegallus, Callinectes amnicola, Paeneus notialis and Mytilus edulis were considered to be abundant in the Lagos lagoon based on the frequency of occurrence in fishermen catches. The analysis of the lead content in muscles of the edible fisheries revealed that the animals accumulated measurable quantity of lead in the edible parts. The level of lead detected in most (12 out of 18 species) of the fisheries species were found to be lower than the daily allowable concentration of 2.0 μg/g standard recommended by the World Health Organisation (WHO). Fishes species with high level of lead in their edible parts include Senegal jack, C. senegallus (2.188 μg/g), Bobo croaker, Pseudotolithus elongatus (2.024 μg/g), Cassava croaker, Pseudotolithus senegalensis (3.157 μg/g), crayfish, Penaeus notialis (25.46μg/g), edible mussel, Mytilus edulis (17.69 μg/g) and crab, Callinectes amnicola (10.19 μg/g). The mean levels of lead in Mytilus edulis, Penaeus notialis, and Callinectes amnicola collected from the Lagos lagoon were about 8 to 24 times higher than the WHO daily allowable standards for lead in sea foods and are therefore unsafe for human consumption. The need for regular monitoring of the levels of metals and other contaminants in edible fisheries resources and collaboration between environmental, health and food agencies to avert human tragedies due to lead accumulation are discussed
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    Open Access
    Toxicological Evaluation and Usefulness of Lipid Peroxidation as Biomarker of Exposure to Crude Oil and Petroleum Products Tested against African Catfish, Clarias gariepinus and Hermit Crab, Clibanarius africanus
    (Nature Environment and Pollution Technology, 2012-03) King, Michael A.; Sogbanmu, Temitope O.; Osibona, Adesola O.; Doherty, Victoria F.; Otitoloju, Adebayo A.
    The toxicological evaluations of crude oil, petrol, kerosene and diesel were carried out against the African Catfish (Clarias gariepinus) fingerlings and Hermit crab (Clibanarius africanus). On the basis of 96hr LC 50 value, petrol (LC 50 = 2.449 mL/L) was found to be the most toxic followed by diesel (LC 50 = 7.839 mL/L), kerosene (LC 50 = 8.095 mL/L), and crude oil (LC 50 = 9.355 mL/L) to Clarias gariepinus. For Clibanarius africanus also, petrol (LC 50 = 4.569mL/L) was the most toxic followed by kerosene (LC 50 = 8.705 mL/L), diesel (LC 50 = 13.852 mL/L) and (LC 50 = 35.955 mL/L). On the basis of the computed susceptibility factor, hermit crab was found to be 2x, 2x, 6.1x and slightly more tolerant than catfish when exposed to petrol, diesel, crude oil and kerosene respectively. The results of the lipid peroxidation assay against juveniles of C. gariepinus showed that the level of malondialdehyde (MDA) in the liver of fish exposed to sublethal concentrations of all the test chemicals increased significantly when compared to control animals. The observed increase in MDA levels in the liver tissues of test animals exposed to crude oil and refined petroleum products was recommended as a good biomarker for early detection of oil related pollution during biomonitoring programmes.
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    Open Access
    Heavy metals in vegetables collected from selected farm and market sites in Lagos, Nigeria
    (2012-09) Kanife, U. C.; Wright, C.; Doherty, V.F; Sogbanmu, Temitope O.
    This study was conducted to determine the concentration of heavy metals (copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd)) in five vegetables viz; Cochorus olitorus (Jew’s mallow), Vernonia amygdalina (Bitter-leaf), Talimum triangulare (Water-leaf), Talifaria occidentalis (Flutted pumpkin) and Spinachcia oleracea (Spinach) and soil collected from selected farm and market sites in industrial, residential and commercial areas of Lagos state. The heavy metals present in the vegetables and soil were analyzed using Atomic Absorption Spectrophotometer (AAS). The results reveal that all the heavy metals were detected in both soil and vegetables from the various sites but at concentrations below the World Health Organisation (WHO) and Food and Agriculture Organisation (FAO) safe limit of 40, 60, 5, and 0.2 mg/kg for copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd) respectively in vegetables. Also, there was no significant difference (p>0.05) between the heavy metals found in vegetables collected from industrial, residential and commercial areas. The results hence shows that vegetables consumed in Lagos state are safe for consumption.
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    Open Access
    Histopathology alterations and lipid peroxidation as biomarkers of hydrocarbon-induced stress in earthworm, Eudrilus eugeniae
    (Environmental Monitoring and Assessment, 2013) Eseigbe, Francis J.; Doherty, Victoria F.; Sogbanmu, Temitope O.; Otitoloju, Adebayo A.
    This study investigated the biomarker responses of the earthworm, Eudrilus eugeniae, exposed to sublethal concentrations of benzene, toluene and xylene (BTX) for a time span of 28 days. Lipid peroxidation (LPO) and histopathological alterations were examined. Toxicological evaluations of BTX were carried out against E. eugeniae. On the basis of the 96-h LC50 value, xylene (1.212 mg/kg) was found to be the most toxic followed by toluene (1.335 mg/kg) and benzene (1.896 mg/kg) was the least toxic. The exposure of earthworms to sublethal concentrations (1/10th and 1/100th of 96 h LC50) of BTX premixed with the substrate (loamy and humus soil) induced pathological changes in the clitella such as severe lesion, necrosis and dark brown pigments. The result of the lipid peroxidation assay showed a significant increase in oxidative damage with LPO values ranging from 2.58–7.8 nM/g in exposed animals when compared to 0.07 nM/g in the control group. The findings from this study suggest the use of LPO and histopathology as useful biomarkers of exposure for early detection of petroleum related stress in terrestrial ecosystems.
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    Open Access
    Joint action toxicity and biochemical effects of binary mixtures of forcados light crude oil and three dispersants against Clarias gariepinus.
    (International Journal of Environmental Research, 2014) Sogbanmu, Temitope O.; Otitoloju, Adebayo A.
    Laboratory-scale experiments were conducted to evaluate the joint action toxicity and biochemical effects of sublethal concentrations of Forcados light crude oil (FLCO) and three dispersants against Clarias gariepinus over a period of 28 days. The derived 96hrLC50 values revealed that the dispersant, DS/TT/066 (0.03mL/L) was the most toxic, followed by dispersant, OC/TT/OSI (0.19mL/L), FLCO (5.06mL/L) and crystal clear oil dispersant (CCOD = 12.06mL/L) the least toxic when acting singly. Joint action toxicity evaluations of FLCO and dispersants showed that the interaction between FLCO:DS/TT/066 and FLCO:OC/TT/OSI was synergistic (synergistic ratio (SR) > 1) with SR values of 10.5 and 3 respectively. However, for the mixture of FLCO:CCOD, the interaction was antagonistic (SR < 1) with SR value of 0.97. The result of the biochemical effects study revealed that malondialdehyde (MDA) levels decreased significantly (P<0.05) in the exposed fishes, reduced gluthathione (GSH) and gluthathione-s-transferase (GST) activities increased significantly (P<0.05) in fishes exposed to FLCO: CCOD mixture alone while there was no significant difference (p>0.05) in superoxide dismutase (SOD) and catalase (CAT) activities in all the exposed fishes compared to control animals. The observed increase in GSH and GST levels in conjunction with a decrease in MDA concentration in the liver of test animals exposed to binary mixtures of FLCO and CCOD reveals the ability of the animals to overcome the effects of lipid peroxidation in this group. Further studies on the mechanism of toxicity of these dispersants in field and laboratory assays are recommended.
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    Open Access
    Lagos lagoon sediment organic extracts and polycyclic aromatic hydrocarbons induce embryotoxic, teratogenic and genotoxic effects in Danio rerio (zebrafish) embryos
    (Environmental Science and Pollution Research, 2016) Sogbanmu, Temitope O.; Nagy, Eszter; Phillips, David H.; Arlt, Volker M.; Otitoloju, Adebayo A.; Bury, Nic R.
    An expansion of anthropogenic activity around Lagos lagoon, Nigeria, has raised concerns over increasing contaminants entering the lagoon's ecosystem. The embryotoxicity, teratogenicity and genotoxicity of sediment organic extracts from four sampling zones around Lagos lagoon, Ilaje, Iddo, Atlas Cove and Apapa, as well as the dominant polycyclic aromatic hydrocarbons (PAHs) identified in water measured during the wet season (naphthalene, phenanthrene, pyrene, benzo[a]pyrene and a mixture of these), were assessed with Danio rerio embryos. Embryos were exposed to varying concentrations of toxicants from 0-72 h post-fertilization (hpf). Embryotoxicity at 72 hpf showed a dose-dependent increase in mortality upon exposure to extracts from all zones, except Atlas Cove. Similarly, higher levels of teratogenic effects, such as increased oedema, and haemorrhage and developmental abnormalities resulted from exposure to extracts from Ilaje, Iddo and Apapa zones. Treatment with single PAHs revealed that significant levels of detrimental effects were obtained only for phenanthrene. The modified comet assay revealed that the oxidative damage to DNA was generally low (<12 %) overall for all sediment extracts, but was significantly elevated with Ilaje and Iddo sediment extracts when compared with solvent controls. Oxidative damage was observed with the single PAHs, phenanthrene and benzo[a]pyrene, as well as with the PAH mixture. This study highlights that Lagos lagoon sediment extracts have teratogenic, embryotoxic and genotoxic properties, which are likely due to the high molecular weight PAHs present in the extracts, some of which are known or are suspected human carcinogens.
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    Open Access
    Bioaccumulation and distribution of organochlorine residues across the food web in Lagos Lagoon, Nigeria
    (AFRICAN JOURNAL OF AQUATIC SCIENCE, 2016) Akinsanya, B.; Alani, R.; Ukwa, U.; Saliu, J.
    Eighteen organochlorine pesticide (OCP) residues were measured in the water, sediment, plankton, benthic invertebrates and fish in various sections of the Lagos Lagoon in 2014 to investigate their bioaccumulation and distribution in the food web. The analysis was done using gas chromatography with an electron capture detector. The concentrations of OCPs in water and sediment ranged from 0.00 to 2.24 μg kg−1 and 0.00 to 1 673.57 μg kg−1, respectively. The sediment had the highest deposition of OCPs, with a total concentration of 2 953.84 μg kg−1. Lindane and heptachlor epoxide had the highest mean concentrations in the sediment, 1 673.57 μg kg−1 and 1 122.74 μg kg−1, respectively, while other OCPs were also found in the biota. Bentho-pelagic fishes had the highest biota-sediment accumulation factor (BSAF) in nine OCP residues, ranging from 1 to 32, and benthic invertebrates had the highest BSAF in three OCP residues, ranging from 1 to 91. The trend in total concentration of OCPs in the lagoon was sediment > Melicertus kerathurus > Eleotris soaresi > Pomadasys jubelini > Tilapia guineensis > Callinectes amnicola > plankton > water. The transfer of organochlorine residues in the food chain and its distribution in the trophic levels was influenced by habitat, environmental conditions, feeding habit and biochemical composition of individual populations. The total residual concentration of OCPs in shellfish and fish ranged between 0.16 ppm and 0.69 ppm. This concentration is quite high compared to the Federal Ministry of Environment limit of <0.01 ppm, and can be harmful if the trend is not checked. Continuous monitoring procedures need to be put in place for environmental safety.
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    Open Access
    Haematologic and Oxidative Stress Effects of Occupational Exposure to Volatile Organic Compounds in Mus musculus at Printing Presses in Lagos, Nigeria.
    (University of Lagos Journal of Basic Medical Sciences, 2016-12) Akeredolu, Excellence O.; Sogbanmu, Temitope O.; Okunoye, Temitope E.
    Background: Solvents and inks used in printing presses are major sources of occupational exposure to Volatile Organic Compounds (VOCs). Objective: The biological effects of short-term occupational exposure to VOCs were investigated using albino mice, Mus musculus. Materials and Methods: Structured questionnaires were administered to printing press workers to assess their knowledge of the potential health effects of VOCs. Hepatic biochemical and haematological indices were evaluated in Mus musculus exposed to VOC emissions from two printing presses in Lagos, Nigeria over a period of 45 days following standard methods. Total VOC (TVOC) levels were determined using a VOC Sampler. Results: The questionnaire analyses revealed that printing press workers in Mushin experienced more health symptoms compared to those at Somolu. There were no significant differences (p>0.05) in the hepatic biochemical and haematological indices between mice at control and exposed locations. Average TVOC level was highest at the printing press in Mushin (466.33±130.78 mg/m3) followed by Somolu (387.00±105.15 mg/m3) and control location (3.50±0.71 mg/m3). Conclusion: The results indicate that short-term exposure to VOCs may not be harmful to human health. However, the questionnaire analyses demonstrated that long-term exposure may be harmful to human health. Hence, it is recommended that a longer-term study be conducted in addition to other biomarkers such as behavioural and physiological indices in order to provide a robust indication of the potential biological effects of these VOCs. The use of personal protection equipment (PPE) and short-term exposure through reduced-time shift regimes are recommended.
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    Open Access
    Spatial behaviour and food choice of the Garden Warbler Sylvia borin during its non-breeding season
    (Ostrich, 2017) Iwajomo, Soladoye B.; Ottosson, Ulf; Thorup, Kasper
    Information regarding the spatial behaviour of migratory bird species on their wintering ground is important in understanding the factors that can influence breeding success and population size. The Garden Warbler Sylvia borin is a migratory species that has been well studied in West Africa. However, information regarding its spatial behaviour during the non-breeding season in sub-Saharan Africa is still limited. Consequently, we investigated the 50% and 95% kernel density home-range size and overlap as well as food choice of 10 radio-tracked Garden Warblers at Amurum, central Nigeria and Obudu, south-eastern Nigeria. Home-range overlap was estimated using the kernelUD function within the package adehabitat in R. The mean home-range was 7.0 ha and 3.3 ha at Amurum and Obudu, respectively, whereas the core of the home-range was on average 1.5 ha and 0.7 ha, respectively. Mean home-ranges were larger than the average territory of individuals on the temperate breeding grounds. Home-range overlap ranged between 19% and 57% at Amurum and 39% and 71% at Obudu, suggesting that Garden Warblers are not territorial during the non-breeding season in Nigeria. The diet of the Garden Warblers at both sites comprised of berries and insects and several individuals were often observed foraging together.
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    Open Access
    Influence of a Dispersant on the Types and Growth of Microbial Hydrocarbon Degraders in a Crude Oil-contaminated Medium
    (Journal of Health & Pollution, 2017-06) Sogbanmu, Temitope O.; Doherty, Victoria F.; Buraimoh, Olanike M.; Arokoyu, Olawunmi F.
    Background: Dispersants are first-order response strategies for oil spill cleanup in an aquatic environment. However, their effects on the biodegradation capacity of indigenous hydrocarbon-degrading microorganisms are little known. Objectives: The influence of a dispersant (DS/TT/066) on the type(s) and growth of hydrocarbon-degrading bacteria (HDB) and hydrocarbon-degrading fungi (HDF) in a crude oil-contaminated medium (water) was investigated in the laboratory for 28 days. Methods: The experiment was set up in duplicates with the first set containing Forcados light crude oil (FLCO) alone in water while the other was a mixture of FLCO and DS/TT/066 (ratio 9:1 v/v). Identification and enumeration of HDB and HDF were conducted according to standard methods. Total petroleum hydrocarbons (TPH) in the test media was analyzed using a gas chromatography/flame ionization detector. Results: The results showed that HDB identified in the FLCO alone included Pseudomonas aeruginosa (day 0), Proteus vulgaris (day 14), P. aeruginosa and Kliebsiella pneumoniae (day 28). However, in the mixture, Escherichia coli was identified on day 14 in addition to the other species observed in FLCO alone. HDF identified in FLCO alone were Candida krusei and Candida albicans (days 0 and 14), Trichosporon cutaneum and C. albicans (day 28). In the mixture, HDF identified were C. albicans (day 0), C. albicans and Aspergillus spp. (days 14 and 28)" Furthermore, the mixture enhanced the growth of HDBF (average counts: 32.5 x 107 and 225 x 106 cfu/mL) compared to FLCO alone (17.5 x 107 and 17.5 x 106 cfu/mL) by day 14 respectively. Total petroleum hydrocarbon reduction was highest (85%) in the mixture compared to 5% in FLCO alone by day 14. Conclusions: The study demonstrated the biodegradation efficiency of E. coli, P. vulgaris (bacteria), C. albicans and Aspergillus spp. (fungi) in a crude oil-contaminated aquatic environment in conjunction with dispersant use. Further studies in the field are recommended in order to explore their potential for rapid and large scale crude oil clean-up operations.
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    Open Access
    Comparative Studies of Genotoxicity and Anti-plasmodial Activities of Stem and Leaf Extracts of Alstonia boonei (De Wild) in Malaria-infected Mice.
    (2017-09) Babamale, O. A.; Iyiola, O. A.; Adeyemi, S. B.; Sulaiman, A. F.; Abdulkareem, A. O.; Anifowoshe, A. T.; Awe, O. D.; Ajani, D.; Ugbomoiko, U. S.
    Drug resistance in malaria infection is a serious public health challenge. Thus, scientific search for alternative treatment measures among the local medicinal plants is exigent. We therefore investigated the anti-plasmodial efficacy and genotoxicity of the methanolic leaf and stem extracts of Alstonia plant at varying concentration (200 mg/kg, 400 mg/kg and 600 mg/kg) in mice infected with chloroquine sensitive Plasmodium berghei. The phytochemical screening of the extract revealed that leaf sample contained significantly higher secondary metabolites, except saponins (p<0.05). Anti-plasmodial activities of the two extracts were duration and dose- dependent. Stem bark extract showed higher curative potential with inhibition rate of 56.71% at 400 mg/kg whereas, leaf extract was efficient at 600mg/kg with 52.15% inhibition rate. Stem bark extract at 400 mg/kg improved the enzymatic activities of the mice; it lowered serum ALT (6.88±4.42) and increased liver ALT (41.07±5.56). Similarly, 400 mg/kg leaf extract showed highest AST (70.65±4.00) and ALT (44.65±7.83) activities in the kidney and liver respectively. Analysis of genotoxicity revealed that micronucleus and abnormal (binucleated, notched and blebbed) were prevalent among the experimental mice which increased significantly (p<0.05) at all concentrations except at 600mg/kg leaf extract. Therefore, this present study indicates that both leaf and stem bark extracts of A. boonei possess anti-plasmodial activity and are less genotoxic when compared with standard drug.
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    Open Access
    Intra-African movements of the African cuckoo Cuculus gularis as revealed by satellite telemetry
    (Journal of Avian Biology, 2018) Iwajomo, Soladoye B.; Willemoes, Mikkel; Ottosson, Ulf; Strandberg, Roine; Thorup, Kasper
    Despite many bird species migrating regularly within the African continent, in response to rainfall and breeding opportunities, documented evidence of the spatiotemporal patterns of such movements is scarce. We use satellite telemetry to document the year round movement of an intra-African migrant breeding in the savannah zone of sub-Saharan Africa, the African cuckoo. After breeding in central Nigeria, the birds migrated to more forested sites in the Adamawa region of Cameroon (n = 2) and western Central African Republic (n = 1). Departure from the breeding ground coincided with deteriorating environmental conditions whereas arrival at the non-breeding sites matched period of increasing vegetation greenness. Migratory movements generally occurred during dark hours. In total, an average distance of 748 km in 66 d was covered during the post-breeding migration and 744 km in 27 d during return journey with considerable individual variation and with more stopover sites used during post-breeding migration. The diversity of migration routes followed suggests a relatively variable or flexible initial migration strategy, high individual route consistency as well as high fidelity for non-breeding grounds.
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    Open Access
    Assessment of Public Health Risk Associated with Consumption of Dominant Edible Animal Species of the Lagos Lagoon, Nigeria
    (Ife Journal of Science, 2018-06) Bawa-Allah, K.; Saliu, J.; Otitoloju, A.
    Heavy metals bio-accumulated in edible aquatic animal species pre-dispose final consumers to adverse health effects of these toxins. Edible animal species were collected from the Lagos lagoon, Nigeria where elevated concentrations of heavy metals have been documented over the years. The concentrations of heavy metals in the animal species were determined and the potential health risk to three age groups of the population, associated with consumption of these species was assessed by calculating Daily Intake of Metals (DIM) and Health Risk Index (HRI). The levels of heavy metals recorded in the tissues of the animal species were below Food and Agricultural Organization (FAO) recommended limits in food, except for Zn (47.60 ppm) in Tympanotonus fuscatus. FAO recommended limits for Zn in food is 30.00 ppm. The DIM and HRI for all heavy metals analyzed were < 1 (unity) in the three animal species and for all age groups indicating that utilization of the species as a protein source does not currently pose serious health risk to consumers. The relative safety associated with utilization of edible animal species from the Lagos lagoon as a protein source reported in this study can only be maintained if heavy metal concentrations in the lagoon are kept within acceptable limits by setting effective effluent limitation standards and enforcing the set standards.