PUBLICATION

Effects of calcium content and humic substances on the toxicity of acriflavine to juvenile zebrafish Danio rerio

Authors
Meinelt, T., Rose, A., and Pietrock, M.
ID
ZDB-PUB-030103-2
Date
2002
Source
Journal of aquatic animal health   14(1): 35-38 (Journal)
Registered Authors
Meinelt, Thomas
Keywords
Antimicrobial agents; Calcium; Dyes; Water chemistry; Water hardness; acriflavine; humic substances; Aquarium culture; Humic acids; Disease control; Therapy; Physicochemical properties; Toxicity tests; Protozoan diseases; Bacterial diseases; Danio rerio
MeSH Terms
none
PubMed
none
Abstract
Acriflavine, a fluorescent acridine dye, is one of the most universal dyes used in fisheries to treat external bacterial and protozoan diseases of fish. However, there is only limited information on the influence of physicochemical water parameters on acriflavine toxicity. Therefore, we conducted laboratory experiments to test the combined effects of water hardness (calcium ion content or Ca2+) and humic substances (HS) on acriflavine toxicity to embryos and larvae of zebrafish Danio rerio, also known as zebra danio, as a test model. Developing fish embryos (prehatch) were exposed to different concentrations of acriflavine (0, 0.2, 0.4, 0.8, 1.6, and 3.2 mg acriflavine/L) in test media containing various combinations of Ca2+ and HS for a period of 144 h. The test media were high () Ca2+ (2 mmol/L) without () HS, Ca2+ with (+) HS (5 mg C/L), low () Ca2+ (0.2 mmol/L) HS, and Ca2+ +HS. Mortality was observed every 24 h up to 144 h. The increasing toxicity ranking of acriflavine based on LC50 values in the different test media was 0.229 mg/L in Ca2+ HS, 0.473 mg/L in Ca2+ HS, 2.059 mg/L in Ca2+ +HS, and 2.339 mg/L in Ca2+ +HS. The HS groups were significantly different from the +HS groups. Because the anion of acriflavine is positively charged, it can bind to the functional groups of the HS, subsequently reducing the amount available for uptake by fish. Calcium ions are able to elevate the toxicity of the dye while HS is reducing. The toxicity, and therefore the therapeutical index, is modified by the content of Ca2+ and HS in the waters.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping