Wilcox, S.J. and T.H. Dietz, 1998. Salinity Tolerance of the Freshwater Bivalve Dreissena polymorpha (Pallas, 1771) (Bivalvia, Dreissenidae), Louisiana State University.

Reprinted with Permission from Nautilus (1998) 111(4): 143-148

Salinity Tolerance of the Freshwater Bivalve Dreissena polymorpha (Pallas, 1771) (Bivalvia, Dreissenidae)

Abstract
The effects of elevated ion concentrations in the bathing medium on osmoregulation and mortality rates were examined in the freshwater bivalve Dreissena polymorpha. Animals acclimated to artificial pondwater (APW) tolerated an acute transfer to approximately 100 mosmol kg(-1) artificial seawater (3.5 parts per thousand ASW), for months, with virtually no mortality. However, there was substantial mortality, within days, when the animals were acutely transferred to dilute ASW greater than 150 mosmol kg(-1) (5 parts per thousand). Dreissena polymorpha rapidly (similar to 12 h) became isosmotic to the bathing medium when exposed to 100 mosmol kg(-1) ASW, although it took 3 d of acclimation before the ion concentrations in the blood stabilized. Salinity tolerance was increased when the animals were acclimated for 3 d to a salinity of 54 mosmol kg(-1) ASW followed by 54 mosmol kg(-1) salinity increases every third day. Although some mussels acclimated for 2 weeks to 377 mosmol kg(-1) ASW could survive direct transfer to APW, survival was improved when the acute reduction in salinity was less than 260 mosmol kg(-1). Dreissena polymorpha has the capacity to tolerate oligohaline water with small fluctuations in salinity.

Entire Paper
Contact: Thomas Dietz, Louisiana State University, Department of Biological Sciences, 202 Life Sciences Bldg., Baton Rouge, LA 70803
Key Words: Zebra_mussel, Basic_biology
Product Type: Research, Basic_biology
User Type: General