Checklist and Habitat Preferences of Dragonflies (Odonata) in Wetlands of the Niger Delta, Delta State

This study develops a checklist and documents the habitat preferences of dragonflies (Order Odonata) in wetland habitats in Delta State, located in Nigeria's South South geopolitical zone. Dragonflies are sensitive bioindicators of wetland health and are among the most charismatic and ecologically important invertebrates in tropical aquatic ecosystems, yet formal species inventories for Delta State wetlands are absent from the literature. Visual encounter surveys and sweep net sampling were conducted at six wetland types: freshwater swamp forest, riverine margins, rice paddies, fish ponds, seasonal pools, and degraded oil-impacted wetlands over three months. Specimens were photographed and identified using regional taxonomic resources. Habitat parameters including vegetation structure, water clarity, and hydroperiod were recorded. A total of 42 Odonata species from 14 families were recorded, comprising 28 dragonfly (Anisoptera) and 14 damselfly (Zygoptera) species. Species richness was highest in freshwater swamp forest margins (31 species) and lowest at oil-impacted sites (8 species), demonstrating the severe impact of petroleum contamination on Odonata diversity. Freshwater specialist species including Trithemis stictica and Hadrothemis defecta were restricted to unpolluted sites. The study delivers the first systematic Odonata checklist for Delta State and proposes dragonfly diversity as a practical biomonitoring tool for assessing oil spill impacts on freshwater ecosystems. Keywords: dragonflies, Odonata, wetlands, Delta State, bioindicators.