Morphological deformities noticed, by Sydney Water taxonomists, in Coenagrionidae damselfly nymphs were believed to be more common in damselflies collected from the Botany Wetlands and were believed to be linked to a degraded environment. To assess this, damselfly nymphs were collected from five sites located in the greater Sydney area.
Sampling occasions over three seasons consisted of a 3 minute sweep net followed by a 20 minute collection of damselflies. Damselflies were then inspected under a microscope for Antennae, Prementum Setae, Lateral Setae and Palpal Setae deformities. Physico-chemical water parameters were measured each sampling occasion. Water and soil samples in spring for chemical analyses.
Results of Analysis of Variance (ANOVA) showed no significant difference in overall deformity occurrence between sites. Results of the first collection showed deformity occurrence in Botany Wetlands Pond 3 (BWP3) was significantly greater than the Hacking River while deformity occurrence in the second collection did not differ significantly between sites. A Chi – square test indicated that the relationship between deformity occurrence and site was not random. Principal Component Analysis of environmental parameters indicated that physicochemical parameters had a positive relationship with deformity occurrence with overall deformity and Prementum setae deformity displaying significant correlations with pH.
Results of this study indicate that there could possibly be a link between deformity occurrence and environmental conditions, although it is not conclusive in regards to what the main drivers of such deformity are.