Premium
Humic substances and the water calcium content change the toxicity of malachite green
Author(s) -
Meinelt T.,
Pietrock M.,
Wienke A.,
Völker F.
Publication year - 2003
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/j.1439-0426.2003.00488.x
Subject(s) - malachite green , toxicity , calcium , biology , acute toxicity , zoology , toxicology , chemistry , organic chemistry , adsorption
Summary Laboratory experiments were conducted to test interactive effects of calcium (Ca 2+ ) content and the presence of humic substance (HS) on malachite green (MAG)‐induced toxicity in fish embryos and larvae by means of a semistatic 144‐h‐embryo‐larval‐test with zebrafish ( Danio rerio ). Two kinds of reconstituted water samples were used to produce the test media by mixing salts into deionized water resulting in either hard water (↑Ca − HS), or soft water (↓Ca − HS). By adding HS two additional test media were produced (↑Ca + HS, ↓Ca + HS). MAG was tested in concentrations of 0.05, 0.10, 0.15, 0.20, 0.25 mg L −1 . The toxicity ranking of MAG (mg L −1 ) to embryos based on 96‐h‐LC 50 in the different test water samples is: ↑Ca − HS (0.061) > ↑Ca + HS (0.123) = ↓Ca − HS (0.12) ≥ ↓Ca + HS (0.134) and on 144‐h‐LC 50 to larvae is: ↑Ca − HS (0.038) > ↑Ca + HS (0.06) > ↓Ca − HS (0.077) = ↓Ca + HS (0.077). Mortality of all the groups was significantly different (P < 0.05). Increased Ca 2+ concentrations did not protect zebrafish embryos and larvae from MAG‐induced toxicity. At high Ca 2+ conditions, the mortality of the embryos as well as of the larvae is reduced in the ↑Ca + HS group relative to the ↑Ca − HS group. Thus, at high Ca 2+ conditions the HS does affect the MAG‐induced mortality. The mechanism which causes the higher toxicity of MAG in the presence of higher Ca 2+ concentrations is poorly understood. A probable explanation could be the stimulation of the calcium‐binding protein calmodulin as well as the calmodulin kinase II in cell membranes in the presence of high Ca 2+ concentrations.