Eastern fairy shrimp

DISTRIBUTION AND HABITAT

The Eastern fairy shrimp is found in eastern North America, from Quebec in the north to Alabama in the south and as far west as Minnesota. The actual extent of its range, however, is not known. Although the species is known to occur in New Jersey, its range within the state is unknown.

Due to their relatively large size, slow movement, and lack of a hard shell, fairy shrimp are prey for many other animals. Because of this, they primarily inhabit vegetated vernal pools where there are fewer predators than in permanent water bodies and where fish cannot survive. They prefer clear cool to cold water with a neutral to low pH and they do not inhabit running water.

DIET

This species of fairy shrimp is a filter feeder which feeds on plankton and other small organic particles in the water.

LIFE CYCLE

Fairy shrimp have a life cycle specialized for living in their temporary vernal pool habitat. They are known as “fairy” shrimp due to the seemingly “magical” way in which they seem to appear out of nowhere in their woodland pools of water, often in locations where they have not been seen in years.

In New Jersey, fairy shrimp usually begin hatching between February and March. They may often be observed swimming under frozen water surfaces. They are sexually mature within 45 days and have a maximum lifespan of 70 days.

Females lay eggs which can withstand heat, cold, and dry conditions. These eggs are drought resistant and may survive several years without water. Fairy shrimp eggs have been known to survive for 15 years before hatching. Eggs overwinter in a dormant stage. Upon exposure to water, the eggs will soon come out of dormancy and will then hatch.

Fairy shrimp cannot tolerate warm water conditions and, in New Jersey, are usually not found within vernal pools after late May or whenever water temperatures reach 68-72° F.