The sensitivity of two cladocerans to water quality variables : alkalinity

• Published in: Archives of environmental contamination and toxicology Vol. 21; no. 2; pp. 224 - 232
• Main Authors: COWGILL, U. M, MILAZZO, D. P
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer-Verlag 01-08-1991; Berlin; New York, NY
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Ceriodaphnia dubia; Daphnia magna; Fundamental and applied biological sciences. Psychology; Invertebrates; Protozoa. Invertebrata; Crustacea; Freshwater environment; Arthropoda; Cladocera; Tolerance; Alkalinity; Invertebrata; Branchiopoda; Daphnia magna
• ISSN: 0090-4341; 1432-0703
• DOI: 10.1007/BF01055341

Results are reported from 3-brood tests on the sensitivity of Daphnia magna and Coriodaphnia dubia to carbonate alkalinity and to the reference toxicant, sodium chloride. Low alkalinity had no statistically significant effect on either species. For both alkalinity and salinity, the most sensitive end-point for D. magna was the EC50 value based on total progeny. For C. dubia the most sensitive end-point for both alkalinity and salinity was the EC50 value based on total progeny and average brood size. As the brood number increased from 1 to 5, the mean brood size for C. dubia relative to that of the controls was enhanced, suggesting a chronic effect at higher alkalinities. Problems associated with measurement of carbonate alkalinity are discussed.