How do mayfly nymph gills differ among species?

Mayfly nymphs possess tracheal gills attached to the outer edges of their abdominal segments, which serve as essential respiratory structures for their aquatic life. These gills vary significantly among species in both form and function:123

• Morphology: The gills may be platelike, feathery, or filamentous in appearance.2
• Specialization: Beyond simple gas exchange, certain gill plates are modified to perform specialized functions, such as moving in ways that generate water currents over the exchange surfaces to improve oxygen uptake.23

These structural variations are often linked to the specific ecological niches the nymphs occupy. For instance, while some species have bodies and legs adapted for burrowing into silt or sand, others possess flattened forms that allow them to cling to bottom materials or enter narrow crevices in swift-moving currents.2