Redtail Fairy Shrimp

Redtail Fairy Shrimp is the most popular fairy shrimp kind in Arizona, and they are classified as Streptocephalus. We call them as Redtail Fairy Shrimp, because their tail is always red except special cases. They habit in ephemeral pools and light muddy water of dry lakes during the monsoon season. Their color can be changed by the amount of sunlight and their food: red pattern, green, white, and blue.

Eggs are 150-190 micrometer in diameter, and the color is light brown and white. Eggs are developed inside of female shrimp's body to tail. The eggs are moved into the brood sack before developed to the full size, and it takes about 1 day to be mature and covered by thick membrane. They stay about 2 more days before being released. Released eggs fall into tangled algae or buried by the mud of pools.

Egg hatching rates In distilled water

Under direct sunlight : About 90% of eggs hatched out. Eggs survived and hatched out very well in the water that had been about 100F(38C) for a few hours.

Under 100W fluorescent lamp : About 75% of eggs hatched out. Less activity of shrimp than the shrimps hatched under sunlight.

Eggs start hatching 7 hours after submerged, and keep hatching for about 72 hours. The baby shrimps of Redtail Fairy Shrimp swim right after hatching like other fairy shrimps, but sometimes they stop swimming and stay at one spot for 10 seconds to a few minutes in the day they hatched out. After the first day, they keep swimming but slower and calm, which is a very different behavior compared to other fairy shrimps. They grow up slower than any other fairy shrimps, but larger and stronger than fairy shrimps of dry lakes. They can even jump out of water to flee from predators, and easily free themselves when entangled by algae.