Baetidae– “Small Minnow Mayflies”

Author: Ashley Maderr

Baetidae Morphospecies 1



Kingdom: Animalia

Phylum: Arthropoda

Class: Insecta

Order: Ephemeroptera

Family: Baetidae


General Description

Baetids are small mayflies, measuring about 10mm in length (not counting their long cerci), which inhabit many freshwater environments. They have three segmented legs on their thorax, and gills extending from abdominal segment 2 through segment 7. They have long oval wingpads (in later instars) and antennae 2-3 times the length if their head width. Their body color ranges from sandy brown to rustic grey.

Functional feeding group: Collector-gatherer

Morphospecies 1

TRW-Tuolumne River at Waterford

BC1-Basin Creek

NFT2-North Fork Tuolumne (mid)

Morphospecies 1: Lateral view of abdominal gills

Morphospecies 1: Lateral view of mouthparts and legs


Morphospecies 2

TRW-Tuolumne River at Waterford

Morphospecies 2: Claws are half the length of tarsi


Morphospecies 2: Simple gills and no tail bands

Morphospecies 3

TRW-Tuolumne River at Waterford