THE XERCES SOCIETY FOR INVERTEBRATE CONSERVATION

Aquatic Invertebrates in Pacific Northwest Freshwater Wetlands
An Identification Guide and Educational Resource

Branchiopoda
(fairy, tadpole and clam shrimp, water fleas)

Key to Orders/Suborders | Order/Suborder List

The freshwater Class Branchiopoda includes four orders. Probably the easiest place to find Branchiopods is in your local pet store, where you'll find the Anostracan Artemia sold as sea monkeys or as brine shrimp for fish food. Most Branchiopoda live in fresh or brackish water, and many inhabit vernal pools.

The appearance, feeding strategies, and life histories of the three orders are truly fascinating, but won't be covered here. For the curious, internet searches for the different orders should pay off. A little water can take them from being dust on parched earth to large (sometimes 3 or 4"), prehistoric-looking creatures in a matter of days!

The following external links have great information on the Branchiopoda:

Anostraca (fairy shrimp) - http://www.sacsplash.org/critters/fairyshr.htm
Notostraca (tadpole shrimp; triops) - http://www.sacsplash.org/critters/leppac.htm
Conchostraca (clam shrimp) - http://www.sacsplash.org/critters/clamshrimp.htm

Nice introduction pages with additional information...
http://www.ucmp.berkeley.edu/arthropoda/crustacea/branchiopoda.html

Key to Orders/Suborders

Anostraca
(brine or fairy shrimp)
Stalked eyes, no carapace, legs in 10-32 (usually 11) pairs.

Cladocera (order Diplostraca)
(water fleas)
Sessile eyes, carapace not covering the head, thorax and abdomen undifferentiated.

Conchostraca
(clam shrimp)
Sessile eyes, bivalved carapace that includes the head, thorax and abdomen undifferentiated.

Image ©David Rosen/Wildside Photography