Results from our pilot Fairy Shrimp survey this spring doubled the number of species known in Vermont…from one to two. Previously, the Knob-lipped Fairy Shrimp (Eubranchipus bundyi) was the only species confirmed in Vermont. We suspected the state had additional species, and after a hectic season of surveying, we now know Vermont also hosts the Intricate Fairy Shrimp/Smooth-lipped Fairy Shrimp (Eubranchipus intricatus). Both species are widespread across North America, but the Intricate Fairy Shrimp is considered rare in nearby Massachusetts, where it is listed as a “Species of Special Concern.”
In some areas of North America, these two species have been found in the same pool. However, as a 1967 paper in the Canadian Journal of Zoology noted, when the two species are found together, Knob-lipped Fairy Shrimp is often found at an advanced stage of development, suggesting that their growth rate is higher than the Intricate Fairy Shrimp at low temperatures.
During our surveys this spring, we sampled Fairy Shrimp at 19 vernal pools across Vermont. We discovered Intricate Fairy Shrimp at six pools in Pomfret, Sharon, Strafford, and Berlin. The Knob-lipped Fairy Shrimp was more widespread, occupying 12 pools from the Champlain Islands, west to Danville, and south to Woodstock (Fig. 1). The shrimp we collected at a pool in Westminster hadn’t matured, and therefore couldn’t be identified to species by our partner on this project, Dr. Christopher Rogers of the Kansas Biological Survey. The Westminster pool was also a site where we hoped to find the Spring Fairy Shrimp (E. vernalis), which is common in Massachusetts and southern New England. We’re also hoping to find the Holman Fairy Shrimp (E. holmanii), which has been documented in both NY and Quebec.
Although we didn’t find both Knob-lipped and Intricate Fairy Shrimp coexisting in any pools we sampled, we plan to visit some sites again later this fall, since different species can be active at different times of the year. We also have plans to survey more pools next year in different regions of the state. You can help by letting us know if you’ve seen these engaging little guys anywhere in Vermont.
The video below shows Intricate Fairy Shrimp at a pool in Pomfret. Video by Peter Brooke.