Open Access

Comparative studies on cellular resistance of bivalves from marine and brackish waters

  • Hans Theede1, 2 and
  • Julius Lassig1, 2
Helgoländer wissenschaftliche Meeresuntersuchungen196716:BF01620693

Published: 1 August 1967


1. The cellular resistance of representatives from four euryhaline poikilosmotic bivalves caught in Büsum (North Sea, 30‰ S), Kieler Förde (Belt Sea, 15‰ S), and Tvärminne (Gulf of Finland, 6‰ S) has been tested. All experiments were performed in October.

2. According to their cellular salinity rangesMacoma baltica andMytilus edulis are more euryhaline thanMya arenaria andCardium edule.

3. The cellular heat resistance decreases in specimens from the North Sea in the following order:Cardium, Mya, Macoma, Mytilus. Among the representatives collected near Tvärminne,Macoma has the highest heat resistance.

4. The cellular freezing resistance in specimens from the North Sea is highest inMytilus. The bivalves of the Gulf of Finland practically lack resistance to freezing.

5. In localities of decreased salinity the cellular resistance of these bivalves to a dilution of the external medium is somewhat increased, but simultaneously the cellular resistance to other environmental factors, such as heat, freezing and high salinity, decreases unspecifically.