Indiscriminate solid waste disposal to the environment without proper treatment poses a serious threat to the public health. This study was carried out to investigate genotoxicity of the raw and simulated leachates samples collected from Amilegbe municipal dump site located in Ilorin metropolis in Nigeria. Some of the physicochemical properties of both raw and simulated leachate samples were determined. Mice were exposed to 1%, 2.5%, 5%, 10% and 25% (raw leachate) and 1%, 5% and 10% concentrations (simulated leachate) respectively for 35 days. Distilled water and colchicine were used for negative and positive control respectively. Two standard genotoxicity tests namely abnormal sperm-head morphology and micronucleus (MN) assays were used to assess possible genotoxicity of the raw and simulated leachates samples. Sperm head morphology assay showed some abnormalities (folded, amorphous, banana shaped, two tails, pin tail among others) and the frequencies of the abnormalities increases was concentrationdependent. Congestion, necrosis, degeneration and appearance of vacuolation were observed in the histopathological analysis of the liver. The histopathological changes were also more pronounced with higher concentrations of raw and simulated leachates. MN and abnormal nuclei frequencies also showed statistically significant differences (p>0.05) such that MN and other nuclear abnormalities reached the maximum at the highest concentration (25% >10% >5% >2.5%>1%). This study shows that the raw and simulated leachates contain potentially genotoxic and cytotoxic substances capable of causing DNA damage. ©JASEM https://dx.doi.org/10.4314/jasem.v21i5.11

The presence of the West African manatee, Trichechus senegalensis in a semi-wild holding facility in Little Stream Farm, Ibesikpo Asutan Local Government Area, presented an opportunity to study directly, aspects of their biology, which hitherto were little known. This study was conducted to identify their plant food preferences and feeding behaviour as a reflection of what may approximate their activities in the wild. The selected plants were weighed (wet weight in kg) with spring balance in batches of 3kg per plant species and offered in batches to the manatee for a specified period (initially for 24 hours, then 4 hours and 10 hours). Of the 15 plant species presented, Emilia sonchifolia, Commelina diffusa, Nymphaea sp., Panicum laxum, Eleusine indica and Rhynchosia sp. had high preference levels while the quantity of Chromolaena sp. consumption was minimal. Bambusa sp., Heliotropium indicum, Ludwigia abyssinica and Hyptis lanceolata were ignored by the animal on repeated presentations. Studies on day-time and night-time feeding showed little difference in quantities of food consumed. However, the maximum consumption of 7kg was observed at daytime feeding on day 4 of the 14 days trial. The result showed that in the event of West African manatee rescue and fostering in temporary holding facilities, these plants’ checklists may come in handy as food materials. They may also come for important considerations as plants whose natural growth and propagation should be encouraged in areas designated for West African manatee conservation.

Indiscriminate discharge of solid waste materials from anthropogenic activities has become a major environmental problem in Nigeria. Leachate samples were collected from Amilegbe dumpsite in Ilorin. The physico-chemical qualities of the leachate as well as heavy metals content were analysed using standard methods. Different concentrations (3.625 %, 6.25 %, 12.5 %, 25.0 %, 50.0 % and 100.0 % (v/v leachate/distilled water)) of leachate samples were prepared. The 96-h LC50 of leachate samples was determined for Clarias gariepinus fingerlings using Probit method. Allium cepa bulbs were also exposed to the different concentrations of the leachate and the root length inhibition and chromosomal aberration were investigated. The results showed certain sample-constituents of the leachate (e.g. pH, BOD, COD, heavy metals) to be at concentrations beyond the maximum permissible limits set by National Environmental Standards and Regulatory Enforcement Agency NESREA. The 96-h LC50 of leachate to Clarias gariepinus fingerlings was 20.26%. Prior to the mortalities at various concentrations, symptoms of toxicity such as rapid and erratic swimming, uncoordinated movement and prolonged gaping of jaws were observed. These observations as well as mortality records were concentration-dependent. The root lengths' mean of A. cepa exposed to different concentrations of the Amilegbe leachate when compared to the control, were statistically significantly different (p<0.05) with concentration dependent. The leachate concentrations were observed to induce different chromosomal aberrations with mitotic indices decreasing as the concentration rises. Leachates from the dumpsite have detrimental effects on both Clarias gariepinus and Allium cepa.

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The tremendous increase in world's population necessitates the increase in food production for the teaming population. Concomitantly, this has led to the increased use of pesticides against insect infestation of food crops and weeds in order to boost crop yield. Nigeria is an agro-based country with its teeming population dependent on agricultural products. Unfortunately, due to pest and weed infestations ARTICLE INFO ABSTRACT Article History

There is a lack of comprehensive understanding of environmental factors influencing fish species’ abundance and distribution in some Nigerian freshwater ecosystems. Our study investigated the environmental factors that drive the abundance and distribution of three economically important fishes – Lates niloticus, Citharinus citharus, and Distichondus rostratus – in Jebba Hydroelectric power dam in Northcentral Nigeria. The species catch abundance was determined using gillnets of different mesh sizes, each measuring 50 m length and 20 m deep. The physicochemical parameters were also assessed following standard methods. A total relative abundance of 47.49%, 27.74%, 24.77% were observed for C. citharus, L. niloticus, and D. rostratus, respectively. The canonical correspondence analysis showed that the catch abundance of L. niloticus associates with water volume, turbidity, phosphate, and hydrogen carbonate. Analysis showed that water hardness, biological oxygen demand (BOD), dissolved oxygen (DO), and chloride levels drive the catch abundance of D. rostratus, while C. citharus associates with temperature and depth. The linear Pearson correlation showed a strong positive relationship of the abundance of L. niloticus with turbidity, phosphate, total suspended solids, hydrogen carbonate, water depth, temperature, and water volume. Our result showed a strong positive association of the abundance of C. citharus with water volume, total dissolved solids, temperature, and water depth. A strong positive relationship of the abundance of D. rostratus with conductivity, water depth, and total dissolved solids was reported. Our study improved knowledge on the environmental factors affecting the abundance of three economically important freshwater fishes in Jebba Hydroelectric dam. Further study is needed to investigate the impact of global climate change on the future distribution of these freshwater fish species.