Montana Field Guide

The longtail tadpole shrimp is the largest species of tadpole or fairy shrimp found in Montana. They can reach up to 2.5-3.5 inches (80 millimeters) in length. This species of tadpole shrimp (order Notostraca) is a member of the crustacean class Branchiopoda. Their large, hardened carapace (shell) makes them look like a fat tadpole swimming through the water or crawling along the bottom. They are important components of many freshwater and saline intermittent or temporary wetlands (Dodson and Frey 2001 and Brendonk et al. 2008). These animals are especially common in seasonal wetlands, where populations are maintained by banks of resting eggs that may remain dormant and can survive drying periods of decades or longer (Brendonck 1996). Mostly found in the prairie ecoregion in habitats of isolated temporary or ephemeral wetlands that are fishless and dry up regularly.

Longtail tadpole shrimps scavenge both living and dead plant and animal materials.