Biting Behaviour of The Filarial Vector Mosquito, Culex quinquefasciatus Say,in an Urban Area

Mosquitoes depend on blood meal for the development of their eggs into offsprings. By knowing the biting behaviour of mosquitoes, we may control mosquito-borne diseases and manage the mosquitoe menace successfully. The present study has been designed to study the biting behaviour of the filarial vector, Culex quinquefasciatus Say, in Madurai, Tamil Nadu, India from July to November 2006. This period was selected as mosquitoes are prevalent during this rainy season. Biting was more during September, October and November and the maximum of 28 caught/man/hour was recorded in November. It is predominantly an exophilic biter, but biting was also noticed as maximum inside the house during July in the study. The density of the biting population in the first floor was more than that of the second floor, which indicated the existence of vertical stratification in the biting behaviour of Cx quinquefasciatus.

Distribution Spread and Environmental Risk Status of Pb, Cd And Cr in Soils of an Open-Air Waste Dumpsite along Tombia/Amassoma Road in Yenagoa Metropolis

In spite of the popularity of open-air waste dumping in Nigeria, it remains a relatively less effective waste management option across the globe because of its associated environmental impacts which includes the release of green house gases (GHGs), persistent organic pollutants (POPs), and metal micro-pollutants amongst others. This study aims to assess the potential environmental risks associated to metals released and vertically delineated across the soil profile within surroundings of dumpsite. Heavy metals in soil samples were acid-digested using the aqua-regia mixture of hydrochloric and nitric acid, followed by instrumentation analysis using the GBC 908 PBMT model atomic absorption spectrophotometer. Contaminated sites showed metal concentrations ranging from 1.493 to 109.460 mg/kg, 0.133 to 4.237 mg/kg, and 5.200 to 25.367 mg/kg for lead, cadmium and chromium respectively, with location 1 land area showing the most contamination. Only soil chromium was observed within regulatory stipulations in all cases. There was significant variation (p < 0.05) between the different sample locations, thereby indicating variations in composition of dumped wastes. Lead and cadmium showed the strongest positive correlation (r = 0.855, p < 0.01) and the application of some heavy metal pollution indicators revealed relatively higher metal loads and degree of contamination, as well as depicting potential ecological risk for soils of location 1. The significant heavy metal contamination of soils in the Tombia-Amassoma waste dumpsite requires that the local environmental sanitation and regulatory authorities take necessary remedial action to forestall the escalation of public health concerns that may emanate from this open-air dump.

The Effect of 2,4 Dimethylamine salt on the Blood, Liver and Muscle of Oryclotagus Cuniculus

Aminoforce containing 720g/l of 2,4-dimethylamine salt induced changes on some enzymes and electrolytes in the male Oryclotagus cuniculus (New Zealand rabbit) were assayed. The organisms were exposed to varying sub-lethal concentrations of the toxicant (720g/l). The concentrations were prepared by pipetting 0.4mls, 0.8mls and 0.12mls making it up to 1.5L clean water in a metal container to make 2.0 mgl-1, 4.0 mgl-1 and 6.0 mgl-1. Aspartate amino transferase (AST), Alanine amino transferase (ALT) and Acid phosphatase (ACP) were assayed in the liver and blood. Results showed that aspartate amino transferase values in the liver and blood were significant (p<0.05) across the concentration of the toxicants. Aspartate amino transferase increased as the concentration of the toxicant increased in the liver, and decreased as the toxicant concentration increased in the blood. Alanine amino transferase in the blood and liver were akin to AST while ACP values increased in the blood and decreased in the liver as the concentration of the toxicant increased. Electrolytes (Sodium (Na+), potassium (K+) and magnesium (Mg2+) ions) showed statistical deviation across the various concentration of the toxicants. Chloride ion values stabilized in the experimental group being not significantly different (p>0.05) across the various concentration of the toxicants. From the study, AST, ALT and ACP are suitable biomarkers for showing sub-lethal effect of aminoforce on Oryclotagus cuniculus. The effects recorded clearly unveiled the potential effect of this xenobiotics on Oryclotagus cuniculus. Therefore, exposure of Oryclotagus cuniculus to this toxicant will affect the organism’s physiological responses and over prolong period of time it could lead to death. Additionally, via food chain man may be affected. The use of this toxicant close to rabbittory should be done with utmost caution.

Assessment of Heavy Metals Contamination of Water and Cupscale Grass (Sacciolepisafricana) along the Epie Creek in Bayelsa State, Nigeria

This study was conducted to investigate the concentration of three heavy metals; iron, chromium and lead in surface water and plant (Sacciolepisafricana) tissues along the Epie creek. This was aimed at determining the heavy metal loading of surface waters and the extent of bioaccumulation in the most prevalent grass species found growing within the river course. Metals were determined using atomic absorption spectrophotometer. Result of water analysis recorded the least and most significant iron concentrations of 3.42 ± 0.06 mg/L and 12.06 ± 0.06 mg/L for Agudama and Edepie axis respectively. Contrastingly, water samples showed chromium and lead levels which were below their instrument measurable limits. Consequently, lead (Pb) and chromium (Cr) levels were within WHO permissible limits, while iron (Fe) exceeded regulatory standard for water samples collected from all field locations. Similarly, iron recorded elevated iron concentrations in plant (cupscale grass) with the least amount being revealed for Igbogene stem (196.63 ± 5.21 mg/kg), and the most concentration been reflected for Edepie root sample (9,423.17 ± 48.55 mg/kg). Even though iron levels prevalently exceeded recommended threshold in plants, the stem were mostly within limit for iron. The only grass sample depicting significant lead amount (0.34 mg/kg) was the stem section collected at Akenfa location. Evidently, metals were least stored in plant stems and most bioaccumulated in plant roots. Furthermore, Cr and Fe are the only significantly correlating metals in plants (r = 0.700, p < 0.01). Overall, the increasing level of Fe in the water environment is further indication of the impact of unregulated dumping of scraps and domestic waste along the creeks embankment.

Impact of Aluminum Phosphide on the Transferases in Liver and muscle of Parophiocephalus obscurus

This study assessed the effect of aluminum phosphide on transferases in liver and muscle of Parophiocephalus obscurus (with mean weight of 42.20±1.5 gSD and mean length of 16.50± cmSD, respectively). The fish were obtained from a private fish farm in Yenagoa Metropolis, Nigeria, and the fish was allowed acclimatized to laboratory condition for 7 days, and then exposed to sublethal concentrations (0.00mg/L, 4.20mg/L, 6.30mg/L and 8.40mg/L) of aluminum phosphide for 14 days. Renewal bioassay was adopted in this study. At the end of the experimental period, the fish was dissected and the muscle and liver were collected, processed and analyzed for alanine aminotransferase and aspartate aminotransferase using colorimetric method. Results of the phosphatase at 0.00mg/L, 4.20mg/L, 6.30mg/L and 8.40mg/L were 94.50±6.44µ/L, 134.47±15.27 µ/L, 106.47±9.21 µ/L and 31.00±3.46 µ/L, respectively (liver), 107.50±9.24, 92.00±6.93 µ/L, 116.50±8.95 µ/L and 146.33±9.33 µ/L respectively (muscle) for aspartate aminotransferase; and 40.00±1.15µ/L, 26.50±3.18µ/L, 14.50±2.02µ/L and 9.80±1.44 µ/L, respectively (liver) and 17.00±1.75µ/L, 8.50±0.87µ/L, 21.00±2.89µ/L and 5.50±0.87 µ/L, respectively (muscle) for alanine aminotransferase. Statistically, there were significant variations (p<0.05) among the various concentration in the transferances. In addition, at some concentration, there was significant variations (p<0.05) between the level of the transferases in the muscle and liver. The significant alteration observed in the various concentrations is an indication that aluminum phosphide is lethal to fish. Therefore, caution should be exercise during the use of aluminum phosphide near biological system.

Phytoplankton Community of Taylor Creek in the Niger Delta Using Diversity Indices

This study evaluated the phytoplankton community of Taylor creek from Polaku to Agbia between November 2013 and July 2014. Sampling was carried out in 12 locations along the stretch of the creek following standard protocol. The phytoplankton enumeration was done and identified accordingly. In all the 12 locations, 100 species of phytoplankton belonging to 14 taxonomic groups including Bacillariophyta (31 species), Chlorophyta (25 species), Pyrrophyta (4 species), Cyanophyta (17 species), Spermatophyta (9 species), Euglenophyta (3 species), Phaeophyta (1 species), Heterokontophyta (2 species), Myxophyta (1 species), Xanthophyta (1 species), Chrysophyta (2 species), Lycopodiophyta (1 species), Cryptophyta (1 species), Dinophyta (2 species). Bacillariophyta, Chlorophyta, Cyanophyta and Spermatophyta with occurrence rate of 36%, 34%, 10% and 10%, respectively were the predominant phytoplankton in the study area occurring in all the locations across the period of the study. The various species have some distinct environmental condition that enable them thrive in their niche, and this determines the structure of the phytoplankton in the study area. The diversity indices provided information about the distribution and health condition of the creek. The study showed significant relationships between Shannon-Wiener, Menhinick, Margalef, equitability and Fisher-alpha indices. The ecosystem showed moderate to heavy pollution based on Shannon Wiener index. There is the need for improved method of waste disposal and other anthropogenic activities being carried in and/ or within the creek.

Behavioral Response and Acute Toxicity of Fingerlings of African Cat Fish, Clarias Gariepinus Exposed to Paraquat Dichloride

This study evaluated the behavioural response and toxicity of paraquat dichloride to fingerlings of Clariasgariepinus. The fishes were acclimatized for 14 days and exposed to sublethal concentration of 0.00 ppm, 16.56 ppm, 22.08 ppm, 27.60 ppm, 33.12 ppm and 38.64 ppm. A 24 hours’ renewal bioassay was adopted in this study. Results showed that the fishes exhibited change in swimming, opercular movement, body pigmentation, surfacing and air gulping. Mortality rate increased significantly at p<0.05 as the concentration of the toxicant increased as well as the exposure period. LC50 values at 24, 48, 72 and 96 were 59.95, 47.59, 38.12 and 26.18ppm, respectively. Based on the results, Paraquat dichloride users need to discard the remains of empty cans properly to avoid contamination. Also there is need to exercise caution when using paraquat dichloride based herbicides in agricultural fields close to surface water resources.

The Effects of Zanzalacht on the Gonotrophic cycle of the Adult House fly Musca Domestica

Melia azedarach extract were applied by feeding the adult female flies on diets mixed with the extracts at different doses. The concentrations of Melia azedarach utilized were 1.8, 2.4 and 3.6%. The gonotrophic cycles of length of 90, 753, 67.6 and 84, 72, 68 hours were obtained after feeding at age 24 hours with diet mixed with doses of 1.8, 2.4 and 3.6% fruit extract; respectively. 98 & 96 hours were the length of gonotrophic cycle in the control groups. The length of 86.7, 72.3, 57.3 and 89.3, 75, 61 hours were obtained after feeding adults at age 48 hours with diets mixed with different doses of fruit extract of the same plant 97.3 and 98.7 hours were the length of the control groups. Proportions of the egg hatching reached 69, 55.3, 49 and 72.9, 64.2, 52 in groups of eggs obtained from 24 hours adults feeding with diets mixed with doses of 1.8, 2.4 and 3.6% fruit extract; respectively. Also 68.7, 53.3,48 5 and 81 2, 70, 56.3 were the proportions of egg hatching obtained from groups at age 48 hours after feeding with diets mixed with the same doses. 85, 77.6, 62.2 and 92.6, 88.9, 84.9 were the proportions of the egg hatching obtained from groups feeding with diets mixed with doses of 1.8, 2.4 and 3.6% fruit extract of Melia azedarach; respectively. The pupae showed larval-pupal intermediates which failed to complete the pupal period and died after emerging from the third larval instar.

Growth Pattern of Saccharomyces cerevisiae in Cassava Mill Effluents

Nigeria is the world leading producer of cassava. During processing of gari from cassava tuber large volume of effluents are discharged in the environment which is toxic to the environment and some of its associated biota. This study evaluated the growth pattern of Saccharomyces cerevisiae in cassava mill effluents. The Saccharomyces cerevisiae was isolated from palm wine following standard microbiological procedure. The Saccharomyces cerevisiae was inoculated into the sterile effluents and incubated for 15 days. At every 3days interval, 1ml of the effluents was obtained from the medium and the population density determined. Results of the growth showed that the population of Saccharomyces cerevisiae were 0.00 x 106 cfu/ml at day 0 (without inoculum), which rose to 2.88 x 106 cfu/ml at day 3, 272.67 x 106 cfu/ml at day 12 and decline slightly at day 15 (13.57 x 106 cfu/ml). There was significant variations (P<0.05) among the various period of study. The study showed that the growth of Saccharomyces cerevisiae in the effluent was optimum at day 12, then after the density began to decline.

The Environmental Impact of Etelebou Flow Station In Surface Water of Gbarain, Bayelsa State, Nigeria

Environmental impact of anthropogenic activities from industrial sources, have become a threat to biodiversity. Water samples were collected from rivers around the flow station, and analysed from some physicochemical parameters and hydrocarbon contents. Result of the physicochemistry was reported for: pH (6.58± 0.04 - 6.76±0.01), conductivity (168.30±13.98 - 194.57±3.78 µS/cm), conductivity 8.29±0.04 - 10.66±0.02 NTU, salinity (0.07±0.00 - 0.09± 0.00 mg/l), and Total Solids (83.96±1.49 - 103.66±0.60mg/l). Other elemental analysis includes: sulphates (2.43±0.01 - 4.28 ±0.02 mg/l), nitrates (0.19±0.01 - 0.28±0.01 mg/l), carbonates (1.14±0.07 - 2.06±0.07 mg/l), calcium (8.45±0.10 - 11.70±0.25 mg/l), magnesium (1.14±0.07 - 2.56±0.03 mg/l), and sodium (4.37±0.15 - 5.62±0.03 mg/l). The values of THC and TPH were 0.92±0.08 - 1.51±0.03, and 0.37±0.13 - 0.76±0.07 mg/l respectively. Generally, the result indicated mild level of contamination in terms of Hydrocarbon contents. However, diagnostic data emerging for physicochemistry and some elemental property indicates the water is unfit for consumption. Notwithstanding, the order on contamination were reported as; downstream > midstream > upstream. Therefore this study concludes that there should be frequent monitoring of the recipient water bodies associated with the flow station in order to check anthropogenic activities, and conserve biodiversity.