Biodiversity and Seasonal Variation of Macro Invertebrates in Four Water Bodies in Odogbolu Local Government Area of Ogun State

Abstract

The biodiversity and seasonal variation of aquatic macroinvertebrates in four different water bodies in Ijagun, Ijele, Odepo and Imaweje in Odogbolu Local Government Area of Ogun State were investigated using modified kick sampling technique between July and December 2014. The aquatic macroinvertebrates were sampled twice in a month using a scoop net (0.5mm mesh size with 0.4m diameter). The collected samples were preserved separately in 10% formalin and later identified. The physical properties (air and water temperature ( o C), water current and water depth) of the water bodies were measured. Analysis of variance and spear man analytical tools were used to analyze the collected data. The different aquatic macro-invertebrates encountered belong to the super phylum Arthropoda, and three phylaviz: Mollusca, Annelida and Nematoda. The most abundant macro-invertebrate group was insects belonging to the orders Diptera (Simuliumyahense, Chironomussp., Anophelissp., and Cricotopus sp. ), Odonata (Agrocnemisfemina, Abiaserica, Macromiasp and Calopteryx sp. ), Coleoptera (Dysticusmarginalis and Hydrophylis sp. ), and Heteroptera (Gerrislacustris). The correlation coefficients (rho) of water depth, water current, water and air temperature in relation to frequency of occurrence of macro invertebrates were found to be -6.2, -4.2, -4.6 and -2.6 respectively. Water depth was the strongest factor that could determine the abundance of organisms. All physical properties showed inverse relationship with variation of aquatic macro invertebrates in the water bodies.