Bresser National Geographic 90-39100 Instrucciones De Uso página 16

The fi bres crinkle in the same way after drying. Observe the similarities and differ-
ences between the different fi bres.
7.3. Saltwater brine shrimps
Accessories:
1. Brine shrimp eggs (20d)
2. Sea salt (20c)
3. Hatchery (18)
4. Yeast (20a)
CAREFUL!
These eggs are not fit for human consumption.
7.3.1. Winter eggs of Artemia salina
Artemia salina are species of brine shrimp typically found in salt lakes — bodies of
water with a higher salinity than even the ocean. During a drought, a salt lake can
become a hostile habitat for organisms, and entire populations of Artemia salina
sometimes die off. During drought conditions, to ensure that the species will re-
populate the salt lake when the drought ends, Artemia salina lay thick-shelled eggs
called winter eggs that can survive for up to ten years in a dormant state. Winter
eggs can withstand heat, cold and chemicals. These eggs hatch when favourable
conditions return to their ambient environment. The eggs provided (20d) are of
this type.
7.3.2. Hatching winter eggs
To hatch the brine shrimps, create a solution with an appropriate salinity and tem-
perature. First, fi ll two containers with a half litre of freshwater each, and let them
both stand for about thirty hours. Next, pour half of the provided salt (20c) into one
container and stir the solution until the salt dissolves. Pour some of this solution
into the hatchery (18). Place a few eggs close to the lid. Position the hatchery
somewhere with plenty of light but not in direct sunlight. The ambient temperature
should ideally hover around 25 °C. As water in the hatchery evaporates, gradually
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add freshwater from the second container. After two to three days, the eggs will
hatch brine shrimp larvae, called nauplii.
7.3.3. Observing Artemia salina under a microscope
Using the pipette (17a), move some larvae from the container to a microscope slide
for examination. When viewing the larvae, you'll notice that they swim through the
solution using hairlike limbs! Each day, examine a few more. You can even view the
entire hatchery under the microscope if you remove its lid. The larvae will mature in
six to ten weeks, depending on the temperature of the water. Soon, you will have
an entire generation of saltwater brine shrimps that reproduce frequently!
7.3.4. Feeding your Artemia salina
Feed your brine shrimps often to keep them alive. The best food is dry powdered
yeast (20a). Give them some every other day. Be careful not to overfeed them, as
doing so can cause the water to stagnate and poison the brine shrimps. If the water
does begin to stagnate (you'll see it darkening), transfer the brine shrimps to the
fresh saline solution you have prepared earlier (see 7.3.2).
8. MicrOcular setup
NOTE:
The MicrOcular only works without the Barlow lens supplied.
Magnifi cation setting is changed by using the MicrOcular and must
be reset by re-focussing.
Remove the Barlow lens (Fig 3, 3) and eyepiece currently in use from the eyepiece
holder (Fig 3, 5) and replace them with the MicrOcular (PC-Ocular) (Fig 4, 4) and
reducer lens (Fig 4, F) as in illustration 4 in the holders (Fig 4, 5).