ASSESSMENT OF ODONATA COMMUNITY STRUCTURE AND SPECIES DIVERSITY ACROSS TWO COASTAL ECOSYSTEMS IN LAGOS STATE, NIGERIA

Abstract

Odonata are globally recognized bioindicators of freshwater ecosystem health. This study examined their species composition, distribution, abundance, and diversity across two ecologically distinct coastal sites in Lagos State namely: Badagry and Ojo. The study also assessed the physicochemical properties of associated water bodies to determine how environmental conditions influence odonate assemblages. A nine-month field survey was conducted across multiple sampling locations in Badagry and Ojo, with systematic collection and identification of Odonata specimens to species level. A total of 1,335 Odonata individuals representing 35 species from two families (Libellulidae and Coenagrionidae) were recorded. Species distribution exhibited marked spatial heterogeneity, with 11 species found exclusively in Badagry and never recorded in Ojo. Diplacodeslefebvri demonstrated strong habitat specificity, with all 64 individuals (8.25 % relative abundance) collected solely from one sampling point (Opposite Lasu foundation, Topo, Badagry). Similarly, Brachythemisleucostica (38 individuals) was found exclusively at the Nigerian French Language Village. Regional distributional asymmetry was also evident, with Orthetrumjulia (n=34) and Chalcostrephiaflavirons (n=27) showing higher abundance in Ojo, while Trithemisstrictica was completely absent from this location. Taxa diversity varied significantly across sites, ranging from 12 individuals at Gberefu Island and Opposite General Hospital to 98 at Nigeria French Village. These findings provide a valuable biodiversity baseline for Lagos State's freshwater ecosystems and emphasize the need for site-specific conservation strategies to protect ecologically sensitive odonate communities across the Lagos coastal wetland mosaic.