• Translucent elongated body, typically yellow to orange in colour (although sometimes greenish)
• 11 pairs of feather-like appendages
  One pair of large compound eyes; two pairs of antennae
• Long segmented tail
• Clear sexual dimorphism: although females typically larger than males, the head of males is much more robust, with distinct claspers (enlarged second antennae) on either side of the mouth
  

• 10-20 mm
  

• Widely distributed in North America between the 40 and 60o N latitude
  
  

Abundance

• Can be found in high abundance where habitat is suitable
• Presence and abundance can fluctuate from year to year in a particular habitat
  

• Small temporary, fishless bodies of water
  

• Entire lifecycle completed during the spring of each year (small populations can sometimes appear in the fall also)
• Hatching of resting eggs typically occurs immediately after spring thaw in late March or early April (Ontario)
  
• Growth is typically rapid during the first two weeks (maturation period), and mating begins shortly thereafter
  

• After mating, development of an egg sac on the lower abdomen of females occurs
• Production of both “summer” and “winter” eggs
• Summer eggs hatch soon after release, while winter eggs remain in the bottom substrate until at least the next freeze-thaw cycle
• Average clutch size is 22 eggs
• Winter eggs are resistant to heat, desiccation and freezing, and can remain viable for many years
  

• Fairy shrimp are filter-feeders, consuming a wide variety of aquatic microorganisms and small particulate matter.
  

• Primarily preyed upon by various aquatic insects, such as predacious diving beetles (Dytiscidae), and other larger vernal pool inhabitats.
• Predation thought not to have a serious impact on fairy shrimp populations (partially due to the fact that they appear very early in vernal pools and complete their lifecycle in a relatively short time span)
  

• The ephemeral presence of these crustaceans and their habitat, along with the unpredictability of their appearance in a given pool from one year to the next, can make conservation a challenge
• During the dry-phase, fairy shrimp habitat can easily be overlooked and potentially destroyed unknowingly