MEASURING AND MODELLING THE DYNAMIC RESPONSE
OF REMOTE MOUNTAIN LAKE ECOSYSTEMS TO
ENVIRONMENTAL CHANGE
A programme of MOuntain LAke Research
MOLAR
Sediment cladocera
PROTOCOL FOR isolation, preparation of slides and counting
Work Package 3.
Jan Fott
Wolfgang Hofman
Charles University, Prague
Max-Planck-Institute for Limnology
Sediment Cladocera: isolation, preparation of slides, counting
1. Equipment
Precision balance
Stirrer hot-plate
Compound microscope and/or good quality stereomicroscope
Counter
2. Isolation of cladoceran remains from the sediment
OPTIONAL (if carbonates are present)
Put the residue from the sieve into a 100 ml beaker, add 10% HCl and repeat (3)
4. Transfer the residue into a labelled vial
3. Preparation of slides and counting
OPTIONAL
a. Fractions >100 m m and 100>(fraction)>40 m m are separated by screening and steps 1 - 6 are carried out separately. This improves the counting of large but scarce remains (e.g. ephippia of Daphnia).
b. Staining or use of phase contrast is left to the discretion of the analyst
c. Glycerol may be added in order to prebent drying up.
4. Expression of the results
Calculation of numbers per gram wet weight of the sediment is carried out according to Frey (1986) tab. 1, total exuviae. Data on lithography (wet density, dry weight, loss on ignition) may be used for recalculation per unit volume, dry weight or organic matter).
5. Permanent slides
Permanent slides will be produced for intercalibrations of taxonomy and circulated among the members of the group. Two methods of making permanent slides are suggested:
a. The fast method: (1) let the subsample on the slide dry, (2) add a drop of 96% alcohol, (3) mount in EUPARAL
b. The method using Chlorazol Black for staining chitin and mounting in PVA: The technique as recommended by Mirka Prazakova was circulated among all members of the group.
6. References
Frey D., 1986: Cladocera Analysis.- p. 227 - 257 in: Berglund B.E. (ed.), Palaeohydrological changes in the temperate zone in the last 15 000 years. Subproject B. Lake and mire environments. Volume II. Specific methods. International Geological Correlation Programme, Project 158.