Zoologist (The)

Assessment of gastrointestinal parasites in burst sewer effluents in Nsukka zone, Enugu State, Nigeria using various diagnostic methods and community practices

I.O. Abdullahi — 2026-06-30

Gastrointestinal parasites threaten public health where sewage is improperly managed. Untreated sewage in the environment increases the risk of disease transmission. This study investigated gastrointestinal parasites in effluents from broken sewers and assessed the Knowledge, Attitudes, and Practices (KAP) of the local population in Nsukka, Enugu State, Nigeria. A total of 463 effluent samples were collected and analysed using zinc sulphate (ZnSO₄) flotation and formol-ether concentration techniques. Structured questionnaires were administered to 367 residents to assess KAP regarding gastrointestinal parasites. Overall parasite prevalence was 28.10% and 9.70% using formol-ether and ZnSO₄, respectively. With formol-ether technique, prevalence varied considerably across sites (χ² = 37.54, p=0.04). Nsukka town had the highest number of species (6). The prevalence of Strongyloides stercoralis was highest, especially in Ibagwa-Aka. Helminths (17.50%) were more common than Protozoa (9.30%). The highest parasite occurrence was in June (31.2%) and July (15.90%), and 56.4% of the respondents considered sewage a source of infection. Open defecation (28.60%) and use of untreated water (46.00%) were prevalent risky behaviours. Burst sewers are reservoirs and pathways for the spread of gastrointestinal parasites. Therefore, proper maintenance of sewers and community health education are necessary to prevent public health risk.

Comparative prevalence of malaria and anaemia among pregnant and non-pregnant women attending selected hospitals in Makurdi, Benue State, Nigeria

T.P. Zawua — 2026-06-30

Malaria is a life-threatening disease and potentially one of the most serious infections during pregnancy in many sub-Saharan nations. This study was conducted to evaluate the distribution of Plasmodium malaria and anaemia among pregnant and non-pregnant women attending selected health facilities within Makurdi, Benue State. Two hundred and fifty volunteered pregnant women and 100 non-pregnant women were randomly selected from 4 different health facilities within Makurdi. Five millilitres (5ml) of blood sample was collected via venipuncture into EDTA bottles. The overall total malaria prevalence was 56.3%. Pregnant and non-pregnant women had malaria prevalence of 65.2% and 34% (p>0.05). Age, education and occupation were significant (p<0.05) factors in the distribution of malaria. Trimester was a significant (p<0.05) factor while parities/gravidities were not significant factors (p>0.0%) in the distribution of malaria. There was a significant (p<0.05) difference in the mean Packed Cell Volume (PCV) across trimesters. Pregnancy with malaria was a significant (p<0.05) factor that exacerbated PCV, leading to anaemia. Pregnant women were more susceptible to malaria and anaemia than non-pregnant women in the present study; hence, pregnant women should develop the habit of sleeping under an insecticide-treated net and should avail themselves of antenatal care.

Seasonal abundance and habitat use by birds in Kano, Nigeria

A.S. Magaji — 2026-06-30

Robust environmental data is a prerequisite to curtailing the current environmental degradation. Understanding species-habitat interactions and species’ response to habitat and seasonal changes is necessary, considering the degradation in the quality and quantity of native habitats. Moreover, assessing the interaction between birds and their habitats is essential in regions like Kano, Nigeria that are subjected to extensive land degradation. During this study, the avian species composition and seasonal variation in abundance and richness in four habitats (farmland, shrubland, wetland, and suburban) were assessed. The line transect sampling method was used to count birds across the wet and dry seasons from 2018 to 2019. Species richness and abundance varied considerably across seasons and habitats. Species abundance was highest in the wetland, while the shrubland had the highest species richness. Environmental factors had significant effects on species abundance and richness. The results indicated that habitat is more important in predicting species composition than season, and there was significant interaction between habitat and season in explaining species abundance and richness. This study highlights the significance of the shrubland and wetland as hotspots for avian biodiversity. Therefore, there is need to prioritise these sites in the course of conservation action by the concerned authority.

Behavioural, haematological, biochemical and histopathological alterations in African Catfish, Clarias gariepinus exposed to dragon (paraquat dichloride)

F.A. Elebe — 2026-06-30

Paraquat herbicide, commonly used to control weeds in farms, could reach the aquatic environment and imperil non-target organisms through run-offs. This study was conducted to assess the impact of paraquat on African catfish Clarias gariepinus. Juvenile C. gariepinus weighing 19.06±7.43g, acclimatised for two weeks under laboratory conditions, were randomly divided into four groups of ten fish each and exposed to 0.00 (control), 794.33, 882.59 and 992.91µg/l of paraquat, labelled A, B, C and D, respectively. The experiment was performed in triplicate for 96 hours. Thereafter, two fish from each tank were removed, and blood was collected for haematological and biochemical analyses, while the kidneys were excised for histopathological examination. The results showed that red blood cells and packed cell volume decreased while the white blood cells increased significantly (p<0.05) compared to the control. The activities of aspartate aminotransferase and alkaline phosphatase significantly increased (p<0.05) while glucose and protein decreased significantly (p<0.05). Histopathological examination revealed concentration-dependent damage to the kidney of the paraquat-exposed groups. This study shows that paraquat is toxic to juvenile fish, therefore, caution should be taken in its application. Policies should be enacted and enforced to protect the environment and non-target species.

Ecological and host determinants of parasite prevalence and diversity in edible land snails from a rural Nigerian community

N.J. Okwerekwu — 2026-06-30

Parasitic infections associated with terrestrial gastropods remain a neglected public health concern in sub-Saharan Africa, sustained by environmental and host-related factors. This study examined the ecological and host-related determinants of parasite prevalence and diversity in edible land snails from Southeast Nigeria. A cross-sectional study was conducted over six months. Snails were collected and identified using standard morphological features. Morphometric parameters (shell length, width, and weight) were recorded, and specimens were grouped into four stages. Snails were euthanized and dissected for parasitological analysis using standard laboratory procedures. A total of 834 snails comprising Achatina achatina, Archachatina marginata and Achatina fulica were examined. Achatina achatina was the most abundant species (346), while A. fulica was the least represented (189). Overall prevalence of infection was 45.6% (380/834), with parasites including protozoans, trematodes, nematodes, and mites. Infection rates were highest in A. achatina (192) and lowest in A. fulica (21). Achatina achatina also exhibited the highest parasite diversity. Edible land snails act as reservoirs of parasitic infections, with patterns influenced by host species. Enhanced public health awareness, improved food safety practices, and sustained epidemiological surveillance are recommended mitigation measures for endemic rural settings.

Comparative assessment of heavy metals concentrations in the muscles, gills and guts of croaker, Pseudotolithus senegalensis from coastal waters of Nigeria and South America

C.I. Ayo-Olalusi — 2026-06-30

Heavy metals pollution of aquatic ecosystems is a major environmental challenge because of its adverse effect on aquatic organisms and human health. This study investigated heavy metals accumulation in Pseudotolithus senegalensis obtained from Nigerian waters and imported from South America. Heavy metals concentrations were determined using Atomic Absorption Spectrophotometry. Zinc, Fe, Cu, Pb, Mn and Cr values were 1.49-11.31μg/g, 3.70-43.52μg/g, 0.6-2.72μg/g, 0.19-2.09μg/g, 0.02-4.47μg/g and 0.83-6.01μg/g, respectively. In the American samples, Zn and Fe were highest in the gut (11.31±0.387μg/g) while Fe was highest in the gills (22.26±0.014μg/g) of Nigerian specimens. Muscle tissues consistently had the lowest Zn and Fe concentrations in both groups. Copper and Cd were not detected in the muscles of the South American samples whereas Cd and Cr were absent in the gills and gut, respectively. Cluster analysis grouped Zn and Fe together whereas Cu, Cr, Cd, Pb and Mn formed a separate cluster. Principal Component Analysis identified two principal components that accounted for 98.89% of the total variance. Overall, gills and guts accumulated higher concentrations of heavy metals than muscles. Heavy metals levels in the Nigerian samples were within WHO limits whereas elevated Pb concentration in the South American samples may pose health risk to consumers.