Evaluation of speculated reproductive habitat for Somatochlora calverti (Corduliidae), a rare and range-restricted dragonfly

Abstract

Globally, freshwater ecosystems and the organisms that depend on them are at risk. Dragonflies and damselflies (collectively, “odonates”) have a history of being used as bioindicators of freshwater habitat quality due to their wide range in environmental sensitivities across species and because they are relatively accessible. However, the nymphal stage is severely understudied compared to the adult stage, which inhibits conservation efforts. Somatochlora calverti is a rare species of dragonfly in the family Corduliidae; members of the genus Somatochlora are notoriously difficult to find and collect in the field as nymphs and adults. Somatochlora calverti is known primarily from the Florida panhandle but has been documented in Alabama, Georgia, and South Carolina. The nymph of this species is speculated to use seepage streams analogous to sympatric congeners; however, the nymph has never been collected in the field and, therefore, its specific microhabitat is unknown. We conducted a review from a suite of informational sources to generate a holistic consensus on what is defined to be suitable reproductive habitat for S. calverti. Sources identified eight major environmental characteristics that are likely to harbor S. calverti: shallow seepage streams, including steephead ravines, with undercut banks and mats of Sphagnum moss adjacent to intact sandhill forest. These ecosystems are being lost and degraded by anthropogenic activity, which has considerable impacts on the persistence of habitat specialists, including S. calverti, and managers’ ability to conserve them.