Conditions of Eleyele dam in Ibadan Nigeria inhabited by Melanoides tuberculata

Abstract

Melanoides tuberculata is now been monitored worldwide because of its fast growing distribution and its economic importance. M. tuberculata, a freshwater mollusc that is an invasive species of freshwater snail, serves as vector transmitting several diseases causing parasites, was found inhabiting Eleyele dam in Ibadan, Nigeria. The prevailing environmental conditions of Eleyele dam were studied between May and October, 2013. Standard methods were used to collect and analyze water samples for physico-chemical variables at four different points on the dam. Conductivity, total solid, water temperature, water depth, dissolved oxygen, biological oxygen demand, nitrate, calcium, alkalinity, total hardness, total suspended solids ranged between 123.95 ± 100.66 mg/L, 143.34 ± 73.21 mg/L 28.42 ± 1.05 °C, 25.73 ± 6.70 cm, 2.71 ± 1.33 mg/L, 0.85 ± 0.90 mg/L, 1.44 ± 1.86 mg/L, 30.70 ± 27.56 mg/L, 43.12 ± 45.04 mg/L, 25.33 ± 23.71 mg/L, 63.15 ± 50.71 mg/L respectively. Calcium significantly correlated with alkalinity (r = 0.864, P < 0.05), total hardness correlated with calcium concentration (r = 0.86, P < 0.05) and alkalinity (r = 0.984, P < 0.05), conductivity with total dissolved solids (r = 0.97, P < 0.05). The observed environmental conditions that favor colonization of M. tuberculata in the Eleyele dam suggest its possible spread in several water bodies in Nigeria. Great precaution must be taking when introducing new aquatic plants into water bodies because this provides a likely route for introduction of nonnative snails as small snails can easily be overlooked on leaves and also during the introduction of M. tuberculata as biocontrol of snails, particularly hydrobes that may carry Schistosoma.