Observation tasks:

Then we put an animal into a petri dish or into an other little vessel.

1.Describe the animal in words:

tiny ,looks like shrimps, has many feet, invertebrate

2.Describe the locomotion of the animal:

The hindfoots are used more actively.

The animal moves sideways along.

At crawfishes: Now put an sheet of a tree from the vessel to the animals.

3.The changing of the behaviour :

The animal look for a cover under or over the leaves..

4.Conclusion of our observation:

The animals are shady.

At crawfishes: Take out the sheet of a tree and put the animal back into the vessel.

Determine the temperature preference

Now we fill a petri dish with hot water (approximately 60°C) and the other petri dish with a common salt/ ice compound. Then we put the one end of the groove on the petri dish with the hot water and the other end on the petri dish with the salt/ice compound.

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Now we measure the temperature of the water with a thermometer or a pyrometer between the lines.

You can also fix two slots into the thick boards of Styrofoam in a distance, which fits to the length of the sheet metal. There you can fill in hot water respectively the salt/ice compound and put the sheet metal on it, so that the one end is cooled and the other is heated.

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NwT practical course 12.03.2007 (part 2)

5. After there was a temperatur difference about 30° K, we wrote a table, in which we had to note the temperature on one side and on the other side we had to note the area ( 0- 10 cm, 10-20 cm, 20-30 cm .....) where the animal will prefer being.

After that we put the animal into the water.

6. Now the animal is in and our task is it note within 2 minutes every 5 seconds in which area ( 0-10 cm, 10-20 cm, 20-30 cm .......) preferred to be. After having done this with one animal, we made the same with six other animals. So we collected enough data to finish our table.

7. With this data we compiled a chart bar.


8. Interpretation of our results: Out of about 7 animals, 4 preferred the cold area (average: 8°C), only 2 stayed in the area of (aver.) 20,6°C

NwT practical course 12.03.2007 (temperature preference of flea cancers)

Material:
a zinc coated plate (100cm x 8cm), sticky tape (breadth at least 2 cm), yard stick, 2 Petri dishes (100 x 20 x 5 cm), thermometer, hot water (approximately 60°C), water with ice, flea cancers, water snails etc.

Lead- through:
Creation of a temperature organ

First of all we measured the plate with the yard stick and made a mark in a distance of 1 cm. Then we took the sticky tape to bond it on the borders of the plate.

We marked the plate longitudinal with 10cm distance, so that we could see how far the animals go. Then we super scribe the markers with 0-10cm; 10-20cm etc.

The borders were bended with a tong, the walls should have a high of 2-3cm. The salient angles should also be bended.

To make it easier to bend the plate, we took two planks, put the plate on them and beat with a hammer on it.

NwT practical course 26.02.2007 (cold water aquarium/light)

Measure of abiotic factors of the aquarium
Light

Measure the light

Material:
GTR, HQI- lamp, measuring tool

Experiment set-up:
Measure the light in different areas of the room for example the light in the room and the HQI-lamp.

Observation:
Area – brightness

Room light: 305 Lux

Straight under the room light: 663 Lux

Straight under the HQI-lamp:2362 Lux

NwT practical course 26.02.2007 (cold water aquarium/nitrogen compounds)

Measure of abiotic factors of the aquarium
Nitrogen compounds

We measured the concentration of the following nitrogen compounds in the aquarium water:
Nitrate, Nitrite and Ammonium

Nitrate
Material:
Water of the aquarium, measure equipment for measuring the concentration of nitrate which is made up of a test-tube (1,5cm calibre and 5cm high), control strips and a colour scale to compare

Experiment set-up:
We filled into the test-tube around 0,5ml of the aquarium water. Next we put a control strip into the test-tube for some seconds, took it out and waited for 1 minute. Then you could compare the colour which appeared on the strip with the colours of the colour scale.

Result:
Our control strip showed nothing. That means that there wasn’t a reaction, there wasn’t a colour to compare.

Comment:
After watching the package of the measure equipment closely, we’ve noticed that the use-by date of that product was already proceed.


Nitrite:
Material:
Water of the aquarium, measure equipment for measuring the concentration of nitrite which is made up of a test-tube (1,5cm calibre and 5cm high), control strips and a colour scale to compare

Experiment set-up:
Look at the experiment set-up of nitrate!

Result:
The colour that appeared was white. That means the concentration of nitrite was 0mg/l.





Ammonium:
Material:
Water of the aquarium, measure equipment for measuring the concentration of ammonium which is made up of a test-tube (1,5cm calibre and 5cm high), control strips and a colour scale to compare.

Experiment set-up:
Look at the experiment set-up of nitrate!

Result:
The colour that appeared was white. That means the concentration of ammonium was 0mg/l.

NwT practical course 26.02.2007 cold water aquarium/oxygen content

Measure of abiotic factors of the aquarium
Oxygen content

Material:
Water of the aquarium, GTR, Interface, oxygen electrode and distillated water for the oxygen electrode.

Experiment set-up:
First we connected the measuring tool (Interface) with the calculator (GTR) and also the oxygen electrode. Then we took the electrode which was in the distillated water before and put it into the aquarium water.

Observation:
First of all we’ve recognised a lot of values of the oxygen concentration, but then it stopped by 6mg/l.

Explanation:
By dipping the oxygen electrode into the water, the oxygen concentration in the water changes all the time until the value stabilised.

NwT practical course 26.02.2007 (cold water aquarium/ pH-value)

Measure of abiotic factors of the aquarium

pH-value

material:

cold water aquarium, measuring tool which is divided into 3 parts, a pillar to fill something in and to the right and left one pillar with colours to compare

experiment set-up:

First we fill some of the aquarium water into the pillar in the middle, and then we add an indicator. Shake the measuring tool a little bit to mix up the water and the indicator, so that the indicator dissolves in the water. Wait some seconds for a colour to compare it with the pillars besides.

Result:

We’ve got a pH-value of 8,5