Section 2: Lakefly Invertebrate Identification
Estimated Time For Lesson: 3 minutes
ID Notes
Stoneflies are poor swimmers with a distinctive swimming motion.
Stoneflies either crawl or reluctantly swims by flexing their body from side to side. Some can be dark in colour while others much lighter. Their bodies are flattened with sturdy legs for crawling on stones.
They have 3 pairs of visible legs
2 tails that are long and slender
1 pair of long antennae
They may have gills on their thorax
Tails can be broken off partially or entirely, so check carefully how many there are.
Stoneflies can be found resting on vegetation or on rocks. Most are highly sensitive to pollution and low oxygen levels.
They are predatory or feed on detritus.
Size: Can be up to 28mm
Photos Credit: Dr Cyril Bennett MBE