Brachycercidae, Coenidae[1] Caenidae, is a family of mayflies, sometimes called "small squaregill mayflies".

Species are found throughout the world in lotic, depositional environments, and they are sprawlers.

[2] Caenids occur in quiet and even stagnant water and are often overlooked because they are so small.

They like to live in silty bottoms, and their gills are specially adapted for such environments.

[2] The Global Biodiversity Information Facility[1] includes: