当前位置： SCI文献检索 > ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY期刊下所有文献 > Effects of algae frozen at different temperatures on chronic assessment endpoints observed with Daphnia magna.

Effects of algae frozen at different temperatures on chronic assessment endpoints observed with Daphnia magna.

Abstract：

:The Daphnia magna 21-day juvenile production test is not yet fully standardized because of many sources of variation. One is the diet provided to daphnids: the ration must be sufficient and the quality of algal cells must be optimal for achieving the required number of offspring defined by the new OECD guidelines. The experiments reported herein first examined the effects of Raphidocelis subcapitata after it had been maintained under four different conditions of storage (4, -20, -80, and -196 degrees C) on the survival, reproductive performance (over 21 days), and growth (ascertained by dry weight) of individually held D. magna for three generations. Under all of the four regimes tested, daphnids survived and reproduced in a manner which fulfilled the current OECD guidelines for a valid test, but the best results were obtained with fresh algae and algae frozen at -80 degrees C. Second, although D. magna has been widely used to determine toxicity of chemical substances, there are no reports in the literature that describe a rigorous study of the nutritional quality of the algae given to daphnids. Therefore, cell number, optical density, amount of organic carbon, and esterasic activity (assessed by intracellular breakdown of FDA to fluorescein) of algae that have been preserved at 4, -20, -80, and -196 degrees C were investigated. This part of the study indicated that freezing had no effect on cell numbers, in contrast to optical density, amount of organic carbon, and esterasic activity. First, it was found that esterasic activity was closely correlated to the reproductive performance of daphnids. It appears important, therefore, to consider the inclusion of this enzymatic activity as part of the routine quality control given to this microinvertebrate chronic procedure.

journal_name

Ecotoxicol Environ Saf

journal_title

Ecotoxicology and environmental safety

authors

Cotelle S,Ferard JF

doi

10.1006/eesa.1996.0017

subject

Has Abstract

pub_date

1996-03-01 00:00:00

pages

137-42

issue

eissn

0147-6513

issn

1090-2414

pii

S0147-6513(96)90017-2

journal_volume

pub_type

杂志文章

在线工具

Effects of algae frozen at different temperatures on chronic assessment endpoints observed with Daphnia magna.