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Fairy shrimp growing guide

Fairy shrimp growing guide

Inside your Fairy Shrimp sets, you will find a white envelope. Inside the envelope is a folded
coffee filter. It contains a small amount of what looks like dust or dirt. In this dust are some of
the most amazing structures you can find on earth – the “cysts” of the vernal pool fairy shrimp.
Each cyst contains a baby shrimp, an embryo in suspended animation. In its drought resistant
casing, it waits patiently for the right time to hatch out and begin its life cycle!
The cysts in this kit are from The Versatile Fairy Shrimp (Branchinecta lindahli). This Fairy
Shrimp is a common, non-endangered, freshwater shrimp that normally lives in the vernal pools
of California and other western United States.
To grow these fascinating little creatures indoors, you will need to create a small artificial vernal
pool to mimic their natural environment. These instructions will guide you through the steps of
growing healthy, happy critters.
1) TIME – These fairy shrimp will do best when hatched in the wintertime, between
Halloween and Valentines Day. Their hatch rate will be the greatest in cool water (50-65
degrees), which is hard to maintain during warm weather. School classrooms in the
winter are perfect for growing fairy shrimp, as they are often poorly heated during the
day and are unheated at night.
2) LOCATION – Choose a level, stable surface, away from heaters and incandescent lights.
Try to find a place where your shrimp pan will not be bumped or spilled. Pick a spot with
sufficient room to allow students to observe the shrimp with their faces close to the pan.
A window ledge is a perfect place as long as they are not in direct sunlight at any time of
the day.
3) LIGHT – Your fairy shrimp will grow bigger and healthier if they are brightly lit with a
light that mimics springtime sunshine. This will also encourage the growth of the algae
and bacteria that they feed on. If your classroom windows will provide 12 hours of light
and 12 hours of dark each day, that should be sufficient. Alternatively (and more
reliably), you may hang or support a fluorescent light fixture about 18” above your
shrimp pan. An old aquarium hood, or fixture designed to mount under counters will
work fine. A simple way to simulate a day/night cycle is to plug your light source into an
appliance timer, set to come on at 6:00 am and go off at 6:00 pm.
4) CONTAINER – A clear glass baking/lasagna pan makes a great tank for your shrimp.
The 3-liter size is the best. They have a high heat capacity that helps to stabilize the water
temperature. They are also easy to clean. Wash your pan with a very diluted bleach
solution. This will clean and sterilize it. Be sure to thoroughly rinse and dry your pan. Do
not use any soap or detergent, as even a little residue is very toxic to baby shrimp.
5) WATER – The best and most economical water for your fairy shrimp to live in is
Arrowhead Mountain Spring Water. Make sure the label says Spring Water. Spring
water mimics the clean but slightly mineralized and alkaline water of a vernal pool. Other
brands of spring water could work as well, but Arrowhead works for sure. Do not use tap
water, as the chemicals and chlorine are toxic to the shrimp.
6) CYSTS – When everything is set up and ready, carefully take your coffee filter out of the
envelope, and hold it over your pan. Open it slowly, and gently dump the “dust” (cysts)
into the water. Rub the sides of the filter against one another to release all the dust. If you
still see a soiled area on the filter, carefully cut out the area with scissors, and float it
soiled side down in the pan. (You can remove the filter paper when the first baby shrimp
appear). The dust will just float on the water, and does not need to be stirred or shaken.
Now you are ready to watch and wait!
7) HATCHING – The cysts will immediately begin to absorb water, but the baby shrimp
will not come out until they are convinced that the water will last. This will take about 24
to 48 hours, sometimes longer, depending on conditions. The baby shrimp will start
swimming right away, in fast jerky movements. They are extremely tiny and easily
missed at first. One way of viewing them is to darken the room and shine a flashlight into
the side of the pan. They are “phototropic,” meaning they are attracted to bright lights.
Leave the flashlight on for several minutes, and the baby shrimp will swim toward the
light. A magnifying glass is very helpful in viewing them at this stage.
8 FEEDING – The day after you first see your baby shrimp swimming around, you may
start feeding them. In the wild, fairy shrimp are filter feeders. They strain tiny particles
out of the water for food, mostly bacteria, algae, and fungal spores. In captivity, they will
live quite happily on a diet of “yeast soup”.
To make yeast soup, dissolve one packet of dried yeast (either bakers or brewers yeast),
one teaspoon of sugar, and a big pinch of crushed fish food flakes in 1/3 cup of hot water
(around 100 degrees, microwave some of your spring water). Mix well, and let it sit for
about an hour to activate the yeast. Be sure to use a container tall enough to allow the
yeast to bubble up. (An old plastic frosting container works well.) Store your “soup” in
the refrigerator or another cool place. This will be enough food to feed your shrimp for
weeks.
To feed your shrimp, stir or shake the mixture thoroughly. (It settles out quickly.) Use an
eyedropper or pipette to drip a few drops of the soup into the water. The baby shrimp are
still extremely tiny and need very little food. You can determine how much food is
enough by using this rule of thumb: The water should be slightly hazy, but not cloudy.
You should be able to see through it. If it becomes cloudy, stop feeding for a day or two
until it clears up. If it becomes extremely clear, feed a little bit more. Increase their food
as they grow. At about 2 weeks, the shrimp will need approximately 1 ml per day. When
they are fully grown, they will need up to 3 mls daily.
9) GROWTH – Your little fairy shrimp will grow very quickly. In a couple of days they will
look like a small crescent. At about 1 week old, they will begin to elongate. They will
reach adulthood when they are about ½ inch long. By four weeks old, they will be close
to 1 inch long. The Versatile Fairy Shrimp have a live span of about 6 to 8 weeks, at
which time they will start to die off from old age.
10) MAINTENANCE – You should try to keep the water level fairly constant in the pan. As
the water evaporates, you will need to top it off with fresh spring water. You might notice
a “scum” developing on the surface of the water. While this film might be unsightly, it is
not dangerous in any way. It can be removed by dragging a piece of paper towel gently
across the top of the water.