Other Mayfly Nymphs

Burrowing, Spiny crawler, Hacklegill, Prong-gilled 

Statistics

Taxonomic order: Ephemeroptera

Taxonomic families: Potomanthidae, Ephemerellidae, Ephemeridae, Leptophlebiidae, Caenidae, Siphlonuridae

Length: up to 3.5 cm

Average life span: 1 to 2 years

Juvenile stage (in water): up to 2 years

Adult stage (out of water): up to 2-4 days

When To See

All year round.

Photo credit: lifeinfreshwater.org & Iain Reid

Habitat

The taxonomic order of mayflies is Ephemeroptera which is derived from the ancient Greek words ephḗmeros meaning to live for a day and pterón, meaning wing.  This describes the final stage of their lifecycle as mayflies spend most of their lives as truly aquatic insects.  They grow by shedding their skins, becoming progressively more and more like the adult flies with each moult.  Finally, when the time is right they emerge from the water as adult flies whose only purpose is to reproduce and complete their life cycle.  As their name suggests they live for a very short time with the final adult stage only having vestigial non functioning mouthparts and lacking the ability to feed.  Nymphs live in flowing waters of rivers and streams with moderate current. They cling onto stones, submerged wood or leaf packs.

How To Identify

Burrowing mayflies (Ephemeridae) – forelimbs modified to allow burrowing in sand and gravel, feathery gills on top of the abdomen

Spiny crawler mayflies (Ephemerellidae) – Abdomen has distinctive spiky protrusions, four pairs of feathery gills on the abdomen covered by protective plates

Hacklegill nymphs (Potamanthidae) – short antennae and mandibular tusks, branched and fringed gills to extract more oxygen from the water

Prong-gilled nymphs (Leptophlebiidae) – flattened head and body, slender, filamentous gills on the sides of the abdominal segments

A stickleback eating a spiny crawler mayfly nymph

Seen It?

Been kicking about in your local river and come across one of these invertebrates? Not sure? Share it with us at trust@forthriverstrust.org, we enjoy chatting about inverts with you.