“We have fairy shrimp. They came from my friend’s vernal pond,” said the director of Schoolmates one morning as Stephen arrived for preschool. The fairy shrimp were swimming in tea-colored water in a large glass jar on one of the tables. Next to the jar was a magnifying glass. Stephen picked up the magnifying glass, looked into the jar, and saw shrimp of different sizes swimming in the water.
Fairy shrimp inhabit vernal ponds in the spring. They are 1/2- to 1 1/2-inch crustaceans. Full-grown fairy shrimp have stalked eyes, two sets of antenna, and eleven pairs of swimming legs. They vary in color depending on what they eat. Usually they are red-orange, but can also appear translucent white to gray, blue, or green.
Fairy shrimp propel themselves with a wave-like beating motion of their legs, while swimming upside down. By changing the angle of their outermost legs they can change the speed of motion.
Female fairy shrimp can produce two types of eggs: thin-shelled “summer” eggs and thick-shelled “winter” eggs. Summer eggs hatch rapidly. The babies will grow and live during the same season they were laid. Winter eggs remain in the mud and leaves at the bottom of the vernal pond. When the water dries up, the eggs remain dormant, hidden among the mud and leaves. The eggs will hatch when the water returns, usually the following year(though eggs have been hatched in a laboratory after fifteen years). The eggs also remain viable at very high (99ºC) temperatures and very low (-190ºC) temperatures. Amazing!
Visit a vernal pond in your area and see if you can discover fairy shrimp. They are a rare and incredible find.