Browsing by Author "Amusata, A. I."
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Item Composition, abundance and diversity of macro-benthic fauna and aquatic insects of Erelu reservoiur and its physical properties(Oyo State College of Agriculture and Technology, 2015-06) Amusata, A. I.; Popoola, K. O. K.; Adedokun, M. A.; Rafiu, R. A.Erelu Reservoir was studied between July 2012 and June 2013, to assess the composition, abundance and diversity of macro-benthic fauna, aquatic insects and its physical parameters. The water, benthic and aquatic insects were collected once every month from three stations. Highest mean value of transparency was 94.42± 5.49cm, Temperature 29.08 ± 0.38°C and Hydrogen ion concentration (PH) 7.27 ± O.l5mg/1. The range for transparency was (70-130)cm, (6.40-7.8) Mg/l for pH and (26-32°C) for temperature. Seven families of benthic macro-fauna; Ampullaridae, Viviparidae, Chironomidae, Lymneaidae, Planorbidae, Thiaridae and Margaritiferidae as well as eight families of aquatic insects; Gyrinidae, Notonectidae, Gerridae,Veliidae, Nepidae, Aeshnidae, Coenagrionidae and Libellulidae were recorded. A total number of 4,632 benthic individuals and 8,648 insects were recorded. Melanoides tuberculata dominated the benthic fauna with a total relative abundance of 90.71% while Planorbidae (Biomphalaria pfeifferi) were the least abundant (0.11 %) by number in the reservoir. Notonectidae (Notonecta sp.) dominated the aquatic insects with abundance of 92.43% while Nepidae (Lacotrephes japonensis) was the least abundant, (0.01 %). Margalef's index (H) in stations 1-3 was (0.60-1.14), Shannon Index (D)was (0.23-0.60), Evenness (E) was (0.41-0.90) for the benthic fauna while H= (0.35-0.50), D= (0.21-0.87) and E= (0.50-2.60) for the aquatic insects. The Margalef's index recorded across the stations for both benthic and aquatic insects showed that the reservoir was moderately polluted.