Related Experiment Video

Updated: Jun 18, 2026

Environmental Screening of Aeromonas hydrophila, Mycobacterium spp., and Pseudocapillaria tomentosa in Zebrafish Systems
09:58

Environmental Screening of Aeromonas hydrophila, Mycobacterium spp., and Pseudocapillaria tomentosa in Zebrafish Systems

Published on: December 8, 2017

Toxicity of peracetic acid (PAA) to tomonts of IIchthyophthirius multifiliis

T Meinelt1, S Matzke, A Stübert

  • 1Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany. meinelt@igb-berlin.de

Diseases of Aquatic Organisms
|November 11, 2009
PubMed

Insights

Ichthyophthirius multifiliis tomonts were tested for susceptibility to peracetic acid (PAA). Newly released and encysted tomonts showed varying susceptibility, with encysted stages being less responsive to chemical treatments.

Area of Science:

  • Aquatic pathology
  • Parasitology
  • Fish health

Background:

  • Ichthyophthirius multifiliis (white spot disease) is a significant parasite affecting freshwater fish.
  • Historically, only the free-living theront stage of I. multifiliis was considered treatable.
  • Understanding the susceptibility of other life stages is crucial for effective disease management.

Purpose of the Study:

  • To develop a method for assessing the toxicity of compounds to different stages of the I. multifiliis life cycle.
  • To determine the efficacy of peracetic acid (PAA) against newly released, encysted, and developing tomonts of I. multifiliis.

Main Methods:

  • Toxicity of Wofasteril E400 (40% peracetic acid, PAA) was evaluated against I. multifiliis tomonts at various times post-sampling from fish.
  • Tomonts were treated immediately, 2.5 hours, and 24 hours after removal from the host.
  • Different concentrations of PAA were applied for varying treatment durations to assess theront production.

Main Results:

  • Immediate treatment of newly released tomonts with 0.6-0.9 mg/L PAA killed 39-82% within 48 hours.
  • Treatment of tomonts 2.5 hours post-sampling with ≥0.5 mg/L PAA significantly reduced theront emergence compared to controls.
  • PAA treatment of tomonts 24 hours post-sampling showed variable results, with no concentration halting theront production.

Conclusions:

  • Newly released and early-stage encysted tomonts of I. multifiliis are susceptible to peracetic acid treatment.
  • Later-stage encysted tomonts exhibit reduced susceptibility to chemical intervention.
  • This study highlights the differential sensitivity of I. multifiliis life stages to PAA, informing treatment strategies.

More Related Videos

Protocol for Acute and Chronic Ecotoxicity Testing of the Turquoise Killifish Nothobranchius furzeri09:43

Protocol for Acute and Chronic Ecotoxicity Testing of the Turquoise Killifish Nothobranchius furzeri

Published on: April 24, 2018

Related Concept Videos

Toxicity Testing in Animals01:23

Toxicity Testing in Animals

Toxicity tests in animals are grounded on two main assumptions: first, the effects observed in laboratory animals can be extrapolated to humans, especially when adjusted for body surface area; second, high-dose exposure in animals is essential to identify potential human hazards from lower doses. This is based on the quantal dose-response concept, which faces the challenge of extrapolating results from relatively few test animals to much larger human populations. For example, a 0.01% incidence...
Toxic Reactions: Overview01:26

Toxic Reactions: Overview

When toxic substances penetrate the human body, they disseminate to various tissues, undergoing metabolic changes. This process yields reactive metabolites that may covalently bind with specific target molecules, resulting in toxicity.
Toxicity falls into two primary categories: local and systemic.
Local toxicity appears at the exposure site, such as protein denaturation caused by caustic substances.
In contrast, systemic toxicity requires the toxic agent's absorption and distribution,...
Anticholinesterase Agents: Poisoning and Treatment01:26

Anticholinesterase Agents: Poisoning and Treatment

Anticholinesterases, also known as cholinesterase inhibitors, work by blocking the breakdown of acetylcholine, leading to its accumulation in the synaptic cleft. This accumulation indirectly enhances both muscarinic and nicotinic actions. These agents are classified as reversible or irreversible based on their mechanism of action.     
Irreversible agents form a strong bond with the cholinesterase enzyme, making it inactive. The breakdown of the phosphorylated enzyme is slower than the...
Physical Properties of Amines01:26

Physical Properties of Amines

Amines with low molecular weight are usually gaseous at room temperature, while those with high molecular weight are liquid or solids in nature. Usually, low molecular weight amines have a rotten fish-like smell. Diamines typically have a pungent smell. For instance, cadaverine and putrescine, depicted in Figure 1, are two molecules responsible for decaying tissue.
Inhalation Anthrax01:25

Inhalation Anthrax

Anthrax is a zoonotic disease caused by Bacillus anthracis, a Gram-positive, spore-forming bacterium. It primarily affects herbivorous animals but can be transmitted to humans through skin contact, ingestion, or inhalation of spores.Cutaneous anthrax, the most common form, typically results from direct contact with bacterial spores through skin abrasions and is generally less severe. Gastrointestinal anthrax results from eating undercooked or contaminated meat. It affects the mouth, throat, or...