Spatial Distribution and Abundance of Freshwater Snails in Relation to Physico-chemical Parameters at Lake Njoboliyo, Adamawa State, Nigeria

Abstract

A study on the spatial distribution and abundance of snail intermediate host in relation to some physico-chemical parameters at Lake Njoboliyo, Adamawa state, Nigeria was carried out. Snail and water samples were collected on a monthly basis from three distinct sites (A, B, and C) between November, 2023 and March, 2024 using a scoop net and handpicking technique. Snails were identified to species level on the basis of their morphological characteristics, using standard keys. Physicochemical parameters of the water body, including temperature, pH, dissolved oxygen, biological oxygen demand, total dissolved solid, electrical conductivity, transparency and water depth were measured following standard procedures. A total of 1,602 freshwater snails were collected, comprising five (5) families and eight (8) different species, including Melanoides tuberculata 490(30.6%), Bellamya unicolor 387(24.2%), Pila ovata 328(20.5%), Lanistes ovum 288(17.9%), Lymnaea natalensis 74(4.6%), Bulinus globosus 19(1.2%), Cleopatra bulimoides 10(0.6%) and Bulinus truncatus 6(0.4%). All snail species were encountered in the three sites of the lake. However, site C recorded the highest snail population, with a total count of 586. Melanoides tuberculata was the most abundant snail species in the study area, comprising approximately 30.6% of the total snail population surveyed, while Bulinus truncatus was the least, constituting about 0.4%. The highest prevalence of snails was observed in the month of January 398(24.85%), while March recorded the least 273(17.04%). There was a significant difference (P<0.05) in the distribution of snails across the sampling months. Transparency was the only significant water parameter influencing the abundance of snail species in the lake. Hence, public awareness on the role of snails in transmitting diseases for efficient control program is highly recommended.