Section 6
Chapter 5,211

Ecological requirements of developing Dreissena polymorpha eggs

Sprung, M.

Archiv fur Hydrobiologie, Supplementband 79(1): 69-86


ISSN/ISBN: 0365-284X
Accession: 005210526

What are the conditions under which Dreissena eggs can develop ? - This question has been pursued in laboratory cultures with respect to factors which may be of ecological importance. It could be demonstrated that fertilization of the eggs can be delayed for 2.5 to 4.75 hours after release depending on the temperature. Sperm keeps its motility longer at most temperatures tested (2 to 22 hours). High sperm concentration (up to 106 sperm ml-1) does not affect the rearing success in a negative way. Rearing is possible between pH values of 7.4 and 9.4 and a temperature span between 12.degree. and 24.degree.C. The developmental speed is clearly temperature dependent. The embryos are fairly robust towards the absence of all ions except Calcium. They turned out to be quite tolerant towards a reduced oxygen content of the water (down to 20 per cent at 18.degree.C). They react quite sensitive to turbulence caused by aeration.

PDF emailed within 1 workday: $29.90