Riffle Beetle vs Labrador Minnow Mayfly

Side-by-side species comparison

Attribute Riffle Beetle Labrador Minnow Mayfly
Scientific Name Elmis aenea Baetis labradoriensis
Order Coleoptera Ephemeroptera
Family Elmidae Baetidae
Size 1.5-2.5 mm 5-8 mm
Habitat Rivers & Streams Rivers & Streams
Diet Detritivores Omnivores
Regions Europe North America
Conservation Least Concern Least Concern

Riffle Beetle

A tiny, dark beetle that spends its entire adult life underwater clinging to rocks in riffles. It breathes using a plastron, a permanent thin film of air.

💡

Did You Know?

Its plastron air film never needs replenishing, allowing it to remain permanently submerged.

Labrador Minnow Mayfly

A small mayfly found in cold northern streams with rapid currents. Nymphs cling to submerged stones and feed on periphyton.

💡

Did You Know?

Nymphs can complete their development in as little as three weeks during warm summer conditions.