skip to main content

Title: Energy allocation in Daphnia magna exposed to xenobiotics: A biochemical approach

A new approach to sublethal aquatic toxicity testing based on a biochemical assessment of the energy budget of Daphnia magna was developed and evaluated. With this method energy consumption (E{sub c}) is estimated by measuring the electron transport activity based on the calorimetric measurement of a tetrazolium salt reduction. Total available energy (E{sub a}) is assessed by measuring the lipid, protein and sugar content of the test organism using calorimetric methods. E{sub a} {minus} E{sup c} can subsequently be calculated and represents the ``surplus`` energy available for growth and reproduction. D. magna neonates were exposed to cadmium and 2,4-dichlorophenoxy acetic acid for 4 days after which the electron transport activity and the total lipid, protein and sugar content of the test organisms were determined. Using the enthalpy of combustion of the different macromolecular groups and converting the oxygen consumption into oxyenthalpic equivalents, an estimation of the total energy budget of the test organisms was made. Additionally, the age specific survival and reproduction and the growth of D. magna populations exposed to the same sublethal concentrations was assessed in 21 day life table experiments. Energy allocation patterns of stressed D. magna obtained with the new biochemical approach were similar to thosemore » obtained with the conventional Scope for Growth determinations. Although more research is needed, comparison between the suborganismal (biochemical) and supraorganismal (life table) endpoints indicate that the proposed short-term assay based on energy allocation could be used to predict long-term effects on the survival, growth and reproduction of daphnids.« less
Authors:
; ;  [1]
  1. Univ. of Ghent (Belgium). Lab. for Biological Research in Aquatic Pollution
Publication Date:
OSTI Identifier:
201200
Report Number(s):
CONF-9511137--
ISBN 1-880611-03-1; TRN: IM9613%%177
Resource Type:
Conference
Resource Relation:
Conference: 2. Society of Environmental Toxicology and Chemistry (SETAC) world conference, Vancouver (Canada), 5-9 Nov 1995; Other Information: PBD: 1995; Related Information: Is Part Of Second SETAC world congress (16. annual meeting): Abstract book. Global environmental protection: Science, politics, and common sense; PB: 378 p.
Publisher:
Society of Environmental Toxicology and Chemistry, Pensacola, FL (United States)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 56 BIOLOGY AND MEDICINE, APPLIED STUDIES; WATER POLLUTION; BIOLOGICAL INDICATORS; DAPHNIA; BIOLOGICAL STRESS; CADMIUM; TOXICITY; ACETIC ACID; XENOBIOTICS; AGE DEPENDENCE; ANIMAL GROWTH; SURVIVAL TIME; BIOASSAY; CALORIMETRY